1
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Tang S, Li Q, Li W, Chen S. Enhancement and Predictable Guidance of Coalescence-Induced Droplet Jumping on V-Shaped Superhydrophobic Surfaces with a Ridge. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 39133052 DOI: 10.1021/acs.langmuir.4c01809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Coalescence-induced droplet jumping has attracted significant attention in recent years. However, achieving a high jumping velocity while predictably regulating the jumping direction of the merged droplets by simple superhydrophobic structures remains a challenge. In this work, a novel V-shaped superhydrophobic surface with a ridge is conceived for enhanced and predictably guided coalescence-induced droplet jumping. By conducting experiments and lattice Boltzmann simulations, it is found that the presence of a ridge in the V-shaped superhydrophobic surface can modify the fluid dynamics during the droplet coalescence process, resulting in a much higher droplet jumping velocity than that achieved by the V-shaped superhydrophobic surface without a ridge. The enhancement of the droplet jumping velocity is mainly attributed to the combined effect of the earlier and more sufficient impingement between the liquid bridge and the ridge, as well as the accelerated droplet contraction by redirecting the internal liquid flow toward the jumping direction. A high normalized jumping velocity of V j * ≈ 0.71 is achieved by the newly designed surface, with a 930% increase in the energy conversion efficiency in comparison with that on a flat surface. Moreover, adjusting the opening direction of the V-groove at different groove angles is found to be an effective method to regulate the droplet jumping direction and expand the range of the jumping angle. Particularly, the droplet jumping angle can be well predicted based on the rotational angle (ω) and the groove angle (α), i.e., θj,p ≈ 90° - 0.5α - ω.
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Affiliation(s)
- Shi Tang
- School of Energy Science and Engineering, Central South University, Changsha 410083, China
| | - Qing Li
- School of Energy Science and Engineering, Central South University, Changsha 410083, China
| | - Wanxin Li
- School of Energy Science and Engineering, Central South University, Changsha 410083, China
| | - Shoutian Chen
- School of Energy Science and Engineering, Central South University, Changsha 410083, China
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2
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Cui J, Wang T, Che Z. Freezing-Melting Mediated Dewetting Transition for Droplets on Superhydrophobic Surfaces with Condensation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:14685-14696. [PMID: 38970799 DOI: 10.1021/acs.langmuir.4c01770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
The water-repellence properties of superhydrophobic surfaces make them promising for many applications. However, in some extreme environments, such as high humidities and low temperatures, condensation on the surface is inevitable, which induces the loss of surface superhydrophobicity. In this study, we propose a freezing-melting strategy to achieve the dewetting transition from the Wenzel state to the Cassie-Baxter state. It requires freezing the droplet by reducing the substrate temperature and then melting the droplet by heating the substrate. The condensation-induced wetting transition from the Cassie-Baxter state to the Wenzel state is analyzed first. Two kinds of superhydrophobic surfaces, i.e., single-scale nanostructured superhydrophobic surface and hierarchical-scale micronanostructured superhydrophobic surface, are compared and their effects on the static contact states and impact processes of droplets are analyzed. The mechanism for the dewetting transition is analyzed by exploring the differences in the micro/nanostructures of the surfaces, and it is attributed to the unique structure and strength of the superhydrophobic surface. These findings will enrich our understanding of the droplet-surface interaction involving phase changes and have great application prospects for the design of superhydrophobic surfaces.
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Affiliation(s)
- Jiawang Cui
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Tianyou Wang
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
- National Industry-Education Platform of Energy Storage, Tianjin University, Tianjin 300350, China
| | - Zhizhao Che
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
- National Industry-Education Platform of Energy Storage, Tianjin University, Tianjin 300350, China
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3
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Zhang Y, Wu C, Jiao S, Gu H, Song Y, Liu Y, Cheng Z. Enhanced and controlled droplet ejection on magnetic responsive polydimethylsiloxane microarrays. J Colloid Interface Sci 2024; 662:563-571. [PMID: 38367574 DOI: 10.1016/j.jcis.2024.01.208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/19/2024]
Abstract
Efficient removal of droplets from solid surfaces is significant in various fields, including fog collection and condensation heat transfer. However, droplets removal on common surfaces with static structures often occurs passively, which limits the possibility of increasing removal efficiency and lacks intelligent controllability. In this paper, an active strategy based on extrusion ejection is proposed and demonstrated on the magnetic responsive polydimethylsiloxane (PDMS) superhydrophobic microplates (MPSM). The MPSM can reversibly transit between the upright and tilted state as the external magnetic field is alternately applied and removed. Under the magnetic field, the direction and trajectories of droplets departure can be intelligently controlled, demonstrating excellent controllability. More importantly, compared with the static structure where the droplet must reach a certain size before departure, droplets can be ejected at smaller sizes as the MPSM is tilted. These advantages are of great significance in many fields, such as a highly efficient fog harvesting system. This strategy of extrusion ejection based on dynamic surface structure control reported in this work may provide fresh ideas for efficient droplet manipulation.
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Affiliation(s)
- Yang Zhang
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Chao Wu
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Shouzheng Jiao
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Haoyu Gu
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Yingbin Song
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Yuyan Liu
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China.
| | - Zhongjun Cheng
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China.
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4
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Josyula T, Kumar Malla L, Thomas TM, Kalichetty SS, Sinha Mahapatra P, Pattamatta A. Fundamentals and Applications of Surface Wetting. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:8293-8326. [PMID: 38587490 DOI: 10.1021/acs.langmuir.3c03339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
In an era defined by an insatiable thirst for sustainable energy solutions, responsible water management, and cutting-edge lab-on-a-chip diagnostics, surface wettability plays a pivotal role in these fields. The seamless integration of fundamental research and the following demonstration of applications on these groundbreaking technologies hinges on manipulating fluid through surface wettability, significantly optimizing performance, enhancing efficiency, and advancing overall sustainability. This Review explores the behavior of liquids when they engage with engineered surfaces, delving into the far-reaching implications of these interactions in various applications. Specifically, we explore surface wetting, dissecting it into three distinctive facets. First, we delve into the fundamental principles that underpin surface wetting. Next, we navigate the intricate liquid-surface interactions, unraveling the complex interplay of various fluid dynamics, as well as heat- and mass-transport mechanisms. Finally, we report on the practical realm, where we scrutinize the myriad applications of these principles in everyday processes and real-world scenarios.
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Affiliation(s)
- Tejaswi Josyula
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Laxman Kumar Malla
- School of Mechanical Sciences, Odisha University of Technology and Research, Bhubaneswar 751029, India
| | - Tibin M Thomas
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | | | - Pallab Sinha Mahapatra
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Arvind Pattamatta
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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5
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Ma C, Wang L, Xu Z, Tong W, Zheng Q. Uniform and Persistent Jumping Detachment of Condensed Nanodroplets. NANO LETTERS 2024; 24:1439-1446. [PMID: 38237068 DOI: 10.1021/acs.nanolett.3c04930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Realizing jumping detachment of condensed droplets from solid surfaces at the smallest sizes possible is vital for applications such as antifogging/frosting and heat transfer. For instance, if droplets uniformly jump at sizes smaller than visible light wavelengths of 400-720 nm, antifogging issues could be resolved. In comparison, the smallest droplets experimentally observed so far to jump uniformly were around 16 μm in radius. Here, we show molecular dynamics (MD) simulations of persistent droplet jumping with a uniform radius down to only 3.6 nm on superhydrophobic thin-walled lattice (TWL) nanostructures integrated with superhydrophilic nanospots. The size cutoff is attributed to the preferential cross-lattice coalescence of island droplets. As an application, the MD results exhibit a 10× boost in the heat transfer coefficient (HTC), showing a -1 scaling law with the maximum droplet radius. We provide phase diagrams for jumping and wetting behaviors to guide the design of lattice structures with advanced antidew performance.
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Affiliation(s)
- Chen Ma
- Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Lin Wang
- Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084, China
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Zhi Xu
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China
| | - Wei Tong
- Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Quanshui Zheng
- Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518057, China
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6
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Liu C, Zhao M, Guo J, Zhang S, Song L, Zheng Y. Exploration of Sweeping Effect: Droplet Coalescence Jumping of a Rolling and Static Droplet. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:2278-2287. [PMID: 38237057 DOI: 10.1021/acs.langmuir.3c03364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
The sweeping effect of merged droplets plays a key role in enhancing application performance due to the continuing coalescence caused by the horizontal jumping velocity. Most studies focused on static droplet coalescence jumping, while moving droplet coalescence is poorly understood. In this work, we experimentally and numerically study the coalescence of a rolling droplet and a static one. When the droplet radius ratio is larger than 0.8, as the dimensionless initial velocity increases and the vertical jumping velocity first decreases and then increases. The critical dimensionless initial velocity Vc* corresponding to the minimum vertical jumping velocity could be estimated as 0.9 ( r s 2 r m 2 ) . When the droplet radius ratio is smaller than 0.8, the dimensionless initial velocity has a positive effect on the vertical jumping velocity. The mechanism of the vertical jumping velocity can be attributed to two parts: liquid bridge impact and retraction of the merged droplet. The squeezing effect generated by the initial velocity between the two droplets promotes the growth of the liquid bridge and enhances the impact effect of the liquid bridge but weakens the upward velocity accumulation caused by the retraction of the merged droplets. However, different from the vertical jumping velocity, the horizontal jumping velocity is approximately proportional to the dimensionless initial velocity. The outcome of our work elucidates a fundamental understanding of a rolling droplet coalescing with a static one.
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Affiliation(s)
- Chuntian Liu
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Meirong Zhao
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Jinwei Guo
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Shiyu Zhang
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Le Song
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Yelong Zheng
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
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7
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Donati M, Regulagadda K, Lam CWE, Milionis A, Sharma CS, Poulikakos D. Metal Surface Engineering for Extreme Sustenance of Jumping Droplet Condensation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1257-1265. [PMID: 38156900 PMCID: PMC10795172 DOI: 10.1021/acs.langmuir.3c02713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024]
Abstract
Water vapor condensation on metallic surfaces is critical to a broad range of applications, ranging from power generation to the chemical and pharmaceutical industries. Enhancing simultaneously the heat transfer efficiency, scalability, and durability of a condenser surface remains a persistent challenge. Coalescence-induced condensing droplet jumping is a capillarity-driven mechanism of self-ejection of microscopic condensate droplets from a surface. This mechanism is highly desired due to the fact that it continuously frees up the surface for new condensate to form directly on the surface, enhancing heat transfer without requiring the presence of the gravitational field. However, this condensate ejection mechanism typically requires the fabrication of surface nanotextures coated by an ultrathin (<10 nm) conformal hydrophobic coating (hydrophobic self-assembled monolayers such as silanes), which results in poor durability. Here, we present a scalable approach for the fabrication of a hierarchically structured superhydrophobic surface on aluminum substrates, which is able to withstand adverse conditions characterized by condensation of superheated steam shear flow at pressure and temperature up to ≈1.42 bar and ≈111 °C, respectively, and velocities in the range ≈3-9 m/s. The synergetic function of micro- and nanotextures, combined with a chemically grafted, robust ultrathin (≈4.0 nm) poly-1H,1H,2H,2H-perfluorodecyl acrylate (pPFDA) coating, which is 1 order of magnitude thinner than the current state of the art, allows the sustenance of long-term coalescence-induced condensate jumping drop condensation for at least 72 h. This yields unprecedented, up to an order of magnitude higher heat transfer coefficients compared to filmwise condensation under the same conditions and significantly outperforms the current state of the art in terms of both durability and performance establishing a new milestone.
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Affiliation(s)
- Matteo Donati
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Kartik Regulagadda
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Cheuk Wing Edmond Lam
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Athanasios Milionis
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Chander Shekhar Sharma
- Thermofluidics
Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Dimos Poulikakos
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
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8
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Tran H, He Z, Pirdavari P, Pack MY. Interplay of Drop Shedding Mechanisms on High Wettability Contrast Biphilic Stripe-Patterned Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:17551-17559. [PMID: 37987777 DOI: 10.1021/acs.langmuir.3c03042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
To improve the rate of DWC, numerous studies have adjusted the distribution of drops through biphilic surface patterning and wettability gradients to control the nucleation and drop shedding rates on the condensing surface, yet the connection between drop shedding mechanisms and surface wettability patterning remains unclear. Moreover, wettability patterning places geometric bounds on the governing forces (i.e., gravity, capillary, and inertia), which drive the droplet shedding mechanisms. Thus, the subsequent influence of droplet distribution along the DWC regions on the shedding mechanisms may not be known a priori. In this study, the area fraction, ADWC, of the DWC and also the DWC region width, LN, were varied between 10 and 50% and 0.5-1.5 mm, respectively, to probe the dominant droplet shedding mechanisms on a high wettability contrast surface (i.e., the contact angle on the DWC was 159 ± 3.4° and the hysteresis 9 ± 3.6°, whereas the FWC was nearly perfectly wetting). Humid air was introduced inside a custom-built chamber with the upright steady-state condensation imaged by both real-time and high-speed imaging techniques. We found that the droplet shedding mechanisms changed with increasing LN where the sliding drop radii are reduced with LN while the jumping drop radii remained unchanged with LN. The maximum drop size for shedding also decreased by 13%, which we attribute to the secondary droplet inertia, which helps gravity overcome the capillary retention force. Lastly, although many studies have probed DWC enhancements via surface wettability patterning, an optimal combination of ADWC and LN provided in this study significantly aids in the improvement of future DWC-based condensers and water collector applications.
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Affiliation(s)
- Huy Tran
- Department of Mechanical Engineering, Baylor University, One Bear Place #97356, Waco, Texas 76798, United States
| | - Ziwen He
- Department of Mechanical Engineering, Baylor University, One Bear Place #97356, Waco, Texas 76798, United States
| | - Pooria Pirdavari
- Department of Mechanical Engineering, Baylor University, One Bear Place #97356, Waco, Texas 76798, United States
| | - Min Y Pack
- Department of Mechanical Engineering, Baylor University, One Bear Place #97356, Waco, Texas 76798, United States
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9
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Thomas TM, Mahapatra PS. Wicking assisted condenser platform with patterned wettability for space application. Sci Rep 2023; 13:18095. [PMID: 37872326 PMCID: PMC10593764 DOI: 10.1038/s41598-023-45294-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/18/2023] [Indexed: 10/25/2023] Open
Abstract
Vapor condensation is extensively used in applications that demand the exchange of a substantial amount of heat energy or the vapor-liquid phase conversion. In conventional condensers, the condensate removal from a subcooled surface is caused by gravity force. This restricts the use of such condensers in space applications or horizontal orientations. The current study demonstrates proof-of-concept of a novel plate-type condenser platform for passively removing condensate from a horizontally oriented surface to the surrounding wicking reservoir without gravity. The condensing surface is engineered with patterned wettabilities, which enables the continuous migration of condensate from the inner region of the condenser surface to the side edges via surface energy gradient. The surrounding wicking reservoir facilitates the continuous absorption of condensate from the side edges. The condensation dynamics on different substrates with patterned wettabilities are investigated, and their condensation heat transfer performance is compared. The continuous migration of condensate drops from a superhydrophobic to a superhydrophilic area can rejuvenate the nucleation sites in the superhydrophobic area, resulting in increased heat transport. The proposed condenser design with engineered wettability can be used for temperature and humidity management applications in space.
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Affiliation(s)
- Tibin M Thomas
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Pallab Sinha Mahapatra
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
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10
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Cui J, Wang T, Che Z. Melting Process of Frozen Sessile Droplets on Superhydrophobic Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:14800-14810. [PMID: 37797346 DOI: 10.1021/acs.langmuir.3c02318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Superhydrophobic surfaces can exhibit icephobicity in many ways due to their large contact angles and small rolling angles. The melting process of frozen droplets on superhydrophobic surfaces is still unclear, hindering the understanding of surface icephobicity. In this experimental study of the melting process of frozen sessile droplets on superhydrophobic surfaces, we find two types of melting morphologies with opposite vortex directions on a single-scale nanostructured (SN) superhydrophobic substrate and a hierarchical-scale micronanostructured (HMN) superhydrophobic substrate. Melting pattern visualizations and flow field measurements showed Marangoni convection and natural convection occurring in the melting sessile droplets. For the HMN superhydrophobic substrate, the internal flow was found to be dominated by Marangoni convection due to the temperature gradient along the surface of the droplet. For the SN superhydrophobic substrate, Marangoni convection was inhibited by the superhydrophobic particles at the surface of the droplet, which were shed from the fragile superhydrophobic substrate during the freezing-melting process, as confirmed by surface characterizations of the substrate and flow measurements of a water pool. These results will help researchers better understand the melting process of frozen droplets and in designing novel icephobic surfaces for numerous applications.
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Affiliation(s)
- Jiawang Cui
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Tianyou Wang
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
- National Industry-Education Platform of Energy Storage, Tianjin University, Tianjin 300350, China
| | - Zhizhao Che
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
- National Industry-Education Platform of Energy Storage, Tianjin University, Tianjin 300350, China
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11
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Rezaee B, Mahlouji Taheri M, Pakzad H, Fakhri M, Moosavi A, Aryanpour M. Enhancement of Dropwise Condensation Heat Transfer through a Sprayable Superhydrophobic Coating. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37267064 DOI: 10.1021/acs.langmuir.3c00947] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Improving the shedding rate of condensed droplets has many applications in industries and daily problems, including increasing heat transfer and self-cleaning properties. One way to achieve this goal is by enhancement of the wetting properties of surfaces. In this research, the hierarchical superhydrophobic coating over aluminum has been applied using a relatively cost-effective method, spraying, which is also applicable to any metal surface used as a condenser. According to the results obtained from the experimental tests, the fabricated surface is highly superhydrophobic, with a contact angle of 158° and contact angle hysteresis of less than 5°. The results show that the presented surface increases the heat transfer coefficient by 20.6% at the subcooling temperature of 25.5 °C when the surface temperature and relative humidity are 70 °C and 98%, respectively. In addition, this coated surface showed great potential at lower surface temperatures by increasing the water condensation rate as much as 50.5% at the subcooling temperature of 12 °C, when the surface temperature and relative humidity are 11.25 °C and 70%, respectively. Therefore, it is found that for the fabricated superhydrophobic paint in the present study, the effectiveness of the dropwise condensation mode profoundly depends on surface temperatures besides subcooling temperatures. In other words, a surface with lower temperatures shows better performance for the same subcooling temperatures. In addition, various types of durability tests are carried out. The results reveal that this coating has good durability against high surface temperatures, submerged conditions for 30 days, imposing hot steam for 150 h, corrosion, and organic solvents. Hence, it is suitable for industrial applications.
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Affiliation(s)
- Behzad Rezaee
- Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran P932+FM4, Iran
| | - Mahmoud Mahlouji Taheri
- Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran P932+FM4, Iran
| | - Hossein Pakzad
- Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran P932+FM4, Iran
| | - Mohammadali Fakhri
- Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran P932+FM4, Iran
| | - Ali Moosavi
- Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran P932+FM4, Iran
| | - Masoud Aryanpour
- Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran P932+FM4, Iran
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12
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Wong HY, Wong LW, Tsang CS, Yan Z, Zhang X, Zhao J, Ly TH. Superhydrophobic Surface Designing for Efficient Atmospheric Water Harvesting Aided by Intelligent Computer Vision. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37200621 DOI: 10.1021/acsami.3c03436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Atmospheric water harvesting (AWH) is a possible solution for the current water crisis on the Earth, and the key process of AWH has been widely applied in commercial dehumidifiers. To improve the energy efficiency of the AWH process, applying a superhydrophobic surface to trigger coalescence-induced jumping could be a promising technique that has attracted extensive interest. While most previous studies focused on optimizing the geometric parameters such as nanoscale surface roughness (<1 μm) or microscale structures (10 μm to a few hundred μm range), which might enhance AWH, here, we report a simple and low-cost approach for superhydrophobic surface engineering, through alkaline oxidation of copper. The prepared medium-sized microflower structures (3-5 μm) by our method could fill the gap of the conventional nano- and microstructures, simultaneously act as the preferable nucleation sites and the promoter for the condensed droplet mobility including droplet coalescence and departure, and eventually benefit the entire AWH performances. Moreover, our AWH structure has been optimized with the aid of machine learning computer vision techniques for droplet dynamic analysis on a micrometer scale. Overall, the alkaline surface oxidation and medium-scale microstructures could provide excellent opportunities for superhydrophobic surfaces for future AWH.
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Affiliation(s)
- Hok Yin Wong
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
| | - Lok Wing Wong
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
| | - Chi Sing Tsang
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
| | - Zhangyuan Yan
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
| | - Xuming Zhang
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong, China
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518000, China
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13
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Tang Y, Yang X, Wang L, Li Y, Zhu D. Dropwise Condensate Comb for Enhanced Heat Transfer. ACS APPLIED MATERIALS & INTERFACES 2023; 15:21549-21561. [PMID: 37083343 DOI: 10.1021/acsami.2c20874] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Dropwise condensation on superhydrophobic surfaces could potentially enhance heat transfer by droplet spontaneous departure via coalescence-induced jumping. However, an uncontrolled droplet size could lead to a significant reduction of heat transfer by condensation, due to large droplets that resulted in a flooding phenomenon on the surface. Here, we introduced a dropwise condensate comb, which consisted of U-shaped protruding hydrophilic stripes and hierarchical micro-nanostructured superhydrophobic background, for a better control of condensation droplet size and departure processes. The dropwise condensate comb with a wettability-contrast surface structure induced droplet removal by flank contact rather than three-phase line contact. We showed that dropwise condensation in this structure could be controlled by designing the width of the superhydrophobic region and height of the protruding hydrophilic stripes. In comparison with a superhydrophobic surface, the average droplet radius was decreased to 12 μm, and the maximum droplet departure radius was decreased to 189 μm by a dropwise condensate comb with 500 μm width of a superhydrophobic region and 258 μm height of a protruding hydrophilic stripe. By controlling the droplet size and departure on hierarchical micro-nanostructured superhydrophobic surfaces, it was experimentally demonstrated that both the heat transfer coefficient and heat flux could be enhanced significantly. Moreover, the dropwise condensate comb showed a maximum heat transfer coefficient of 379 kW m-2 K-1 at a low subcooling temperature, which was 85% higher than that of a superhydrophobic surface, and it showed 113% improvement of high heat flux or heat transfer coefficient when it was compared with that of the hierarchical micro-nanostructured superhydrophobic surface at a high subcooling temperature of ∼10.6 K. This work could potentially transform the design and fabrication space for high-performance heat transfer devices by spatial control of condensation droplet size and departure processes.
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Affiliation(s)
- Yu Tang
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Xiaolong Yang
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Ligeng Wang
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Yimin Li
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Di Zhu
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
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14
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Upot NV, Fazle Rabbi K, Khodakarami S, Ho JY, Kohler Mendizabal J, Miljkovic N. Advances in micro and nanoengineered surfaces for enhancing boiling and condensation heat transfer: a review. NANOSCALE ADVANCES 2023; 5:1232-1270. [PMID: 36866258 PMCID: PMC9972872 DOI: 10.1039/d2na00669c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/04/2022] [Indexed: 06/18/2023]
Abstract
Liquid-vapor phase change phenomena such as boiling and condensation are processes widely implemented in industrial systems such as power plants, refrigeration and air conditioning systems, desalination plants, water processing installations and thermal management devices due to their enhanced heat transfer capability when compared to single-phase processes. The last decade has seen significant advances in the development and application of micro and nanostructured surfaces to enhance phase change heat transfer. Phase change heat transfer enhancement mechanisms on micro and nanostructures are significantly different from those on conventional surfaces. In this review, we provide a comprehensive summary of the effects of micro and nanostructure morphology and surface chemistry on phase change phenomena. Our review elucidates how various rational designs of micro and nanostructures can be utilized to increase heat flux and heat transfer coefficient in the case of both boiling and condensation at different environmental conditions by manipulating surface wetting and nucleation rate. We also discuss phase change heat transfer performance of liquids having higher surface tension such as water and lower surface tension liquids such as dielectric fluids, hydrocarbons and refrigerants. We discuss the effects of micro/nanostructures on boiling and condensation in both external quiescent and internal flow conditions. The review also outlines limitations of micro/nanostructures and discusses the rational development of structures to mitigate these limitations. We end the review by summarizing recent machine learning approaches for predicting heat transfer performance of micro and nanostructured surfaces in boiling and condensation applications.
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Affiliation(s)
- Nithin Vinod Upot
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Kazi Fazle Rabbi
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Siavash Khodakarami
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Jin Yao Ho
- School of Mechanical and Aerospace Engineering, Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Republic of Singapore
| | - Johannes Kohler Mendizabal
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- Materials Research Laboratory, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University 744 Moto-oka, Nishi-ku Fukuoka 819-0395 Japan
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15
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Abstract
Large droplets emerging during dropwise condensation impair surface properties such as anti-fogging/frosting ability and heat transfer efficiency. How to spontaneously detach massive randomly distributed droplets with controlled sizes has remained a challenge. Herein, we present a solution called condensation droplet sieve, through fabricating microscale thin-walled lattice structures coated with a superhydrophobic layer. Growing droplets were observed to jump off this surface once becoming slightly larger than the lattices. The maximum radius and residual volume of droplets were strictly confined to 16 μm and 3.2 nl/mm2 respectively. We reveal that this droplet radius cut off is attributed to the large tolerance of coalescence mismatch for jumping and effective isolation of droplets between neighboring lattices. Our work brings forth a strategy for the design and fabrication of high-performance anti-dew materials. Spontaneous droplet jumping and control of dropwise condensation are relevant for water-harvesting, heat transfer and anti-frosting applications. The authors design a superhydrophobic surface with microscale thin-walled lattice structure to achieve effective jumping of droplets with specified radius range.
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16
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Abstract
Water harvesting from air has the potential to alleviate water scarcity in arid regions around the globe. To achieve efficient water harvesting, we prefer rapid vapor condensation and droplet collection simultaneously. Prior techniques are not able to separate the vapor and liquid flow, so the condensed droplets always hinder the vapor condensation. In this work, we report a flow-separation condensation mode on a hydrophilic reentrant slippery liquid-infused porous surface. The slippery reentrant channels absorb the condensed droplets, lock the liquid columns inside, and transport them to the end of each channel. As a result, the sustainable flow separation significantly increases the water harvesting rate. Water harvesting from air is desired for decentralized water supply wherever water is needed. When water vapor is condensed as droplets on a surface the unremoved droplets act as thermal barriers. A surface that can provide continual droplet-free areas for nucleation is favorable for condensation water harvesting. Here, we report a flow-separation condensation mode on a hydrophilic reentrant slippery liquid-infused porous surface (SLIPS) that rapidly removes droplets with diameters above 50 μm. The slippery reentrant channels lock the liquid columns inside and transport them to the end of each channel. We demonstrate that the liquid columns can harvest the droplets on top of the hydrophilic reentrant SLIPS at a high droplet removal frequency of 130 Hz/mm2. The sustainable flow separation without flooding increases the water harvesting rate by 110% compared to the state-of-the-art hydrophilic flat SLIPS. Such a flow-separation condensation approach paves a way for water harvesting.
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17
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Hu Y, Jiang K, Liew KM, Zhang LW. Nanoarray-Embedded Hierarchical Surfaces for Highly Durable Dropwise Condensation. Research (Wash D C) 2022; 2022:9789657. [PMID: 36061819 PMCID: PMC9394060 DOI: 10.34133/2022/9789657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/20/2022] [Indexed: 12/02/2022] Open
Abstract
Durable dropwise condensation of saturated vapor is of significance for heat transfer and energy saving in extensive industrial applications. While numerous superhydrophobic surfaces can promote steam condensation, maintaining discrete microdroplets on surfaces without the formation of a flooded filmwise condensation at high subcooling remains challenging. Here, we report the development of carbon nanotube array-embedded hierarchical composite surfaces that enable ultra-durable dropwise condensation under a wide range of subcooling (ΔTsub = 8 K–38 K), which outperforms existing nanowire surfaces. This performance stems from the combined strategies of the hydrophobic nanostructures that allow efficient surface renewal and the patterned hydrophilic micro frames that protect the nanostructures and also accelerate droplet nucleation. The synergistic effects of the composite design ensure sustained Cassie wetting mode and capillarity-governed droplet mobility (Bond number < 0.055) as well as the large specific volume of condensed droplets, which contributes to the enhanced condensation heat transfer. Our design provides a feasible alternative for efficiently transferring heat in a vapor environment with relatively high temperatures through the tunable multiscale morphology.
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Affiliation(s)
- Yue Hu
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Kaili Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics & Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
| | - Kim Meow Liew
- Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Centre for Nature-Inspired Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Lu-Wen Zhang
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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18
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Coalescence‐induced jumping of microdroplets on superhydrophobic surfaces – A numerical study. CAN J CHEM ENG 2022. [DOI: 10.1002/cjce.24591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Ho JY, Rabbi KF, Khodakarami S, Sett S, Wong TN, Leong KC, King WP, Miljkovic N. Ultrascalable Surface Structuring Strategy of Metal Additively Manufactured Materials for Enhanced Condensation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104454. [PMID: 35780492 PMCID: PMC9404399 DOI: 10.1002/advs.202104454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Metal additive manufacturing (AM) enables unparalleled design freedom for the development of optimized devices in a plethora of applications. The requirement for the use of nonconventional aluminum alloys such as AlSi10Mg has made the rational micro/nanostructuring of metal AM challenging. Here, the techniques are developed and the fundamental mechanisms governing the micro/nanostructuring of AlSi10Mg, the most common metal AM material, are investigated. A surface structuring technique is rationally devised to form previously unexplored two-tier nanoscale architectures that enable remarkably low adhesion, excellent resilience to condensation flooding, and enhanced liquid-vapor phase transition. Using condensation as a demonstration framework, it is shown that the two-tier nanostructures achieve 6× higher heat transfer coefficient when compared to the best filmwise condensation. The study demonstrates that AM-enabled nanostructuring is optimal for confining droplets while reducing adhesion to facilitate droplet detachment. Extensive benchmarking with past reported data shows that the demonstrated heat transfer enhancement has not been achieved previously under high supersaturation conditions using conventional aluminum, further motivating the need for AM nanostructures. Finally, it has been demonstrated that the synergistic combination of wide AM design freedom and optimal AM nanostructuring method can provide an ultracompact condenser having excellent thermal performance and power density.
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Affiliation(s)
- Jin Yao Ho
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
| | - Kazi Fazle Rabbi
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Siavash Khodakarami
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Soumyadip Sett
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Teck Neng Wong
- Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
| | - Kai Choong Leong
- Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
| | - William P King
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Department of Electrical and Computer EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Materials Research LaboratoryUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Nenad Miljkovic
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Department of Electrical and Computer EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Materials Research LaboratoryUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- International Institute for Carbon Neutral Energy Research (WPI‐I2CNER)Kyushu University744 Moto‐okaNishi‐kuFukuoka819‐0395Japan
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20
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Ho JY, Fazle Rabbi K, Khodakarami S, Yan X, Li L, Wong TN, Leong KC, Miljkovic N. Tunable and Robust Nanostructuring for Multifunctional Metal Additively Manufactured Interfaces. NANO LETTERS 2022; 22:2650-2659. [PMID: 35245074 DOI: 10.1021/acs.nanolett.1c04463] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Novel processing phenomena coupled with various alloying materials used in metal additive manufacturing (AM) have opened opportunities for the development of previously unexplored micro-/nanostructures. A rationally devised structure nanofabrication strategy of AM surfaces that can tailor the interface morphology and chemistry has the potential for many applications. Here, through an understanding of grain formation mechanisms during AM, we develop a facile method for tuning micro-/nanostructures of one of the most used AM alloys and rationally optimize the morphology for applications requiring low surface adhesion. We demonstrate that optimized AM structures reduce the adhesion of impaling water droplets and significantly delay icing time. The structure can also be altered and optimized for antiflooding jumping-droplet condensation that exhibits significant enhancement in heat transfer performance in comparison to nanostructures formed on conventional Al alloys. In addition to demonstrating the potential of functionalized AM surfaces, this work also provides guidelines for surface-structuring optimization applicable to other AM metals.
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Affiliation(s)
- Jin Yao Ho
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - Kazi Fazle Rabbi
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Siavash Khodakarami
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Xiao Yan
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Longnan Li
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Teck Neng Wong
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - K C Leong
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
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21
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Fu X, Zhu Q, Liu D, Liu B, Kuang L, Feng Y, Chu F, Huang Z. Enhanced Moisture Condensation on Hierarchical Structured Superhydrophobic-Hydrophilic Patterned Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:863-869. [PMID: 34968065 DOI: 10.1021/acs.langmuir.1c03076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Patterned surfaces combining hydrophobic and hydrophilic properties show great promise in moisture condensation; however, a comprehensive understanding of the multiscale interfacial behavior and the further controlling method is still lacking. In this paper, we studied the moisture condensation on a hybrid superhydrophobic-hydrophilic surface with hierarchical structures from micro- to nanoscale. For the first time, we demonstrated the effects of wettability difference and microstructure size on the final condensation efficiency. By optimizing the wettability difference, sub-millimeter pattern width, and microstructure size, maximum 90% enhancement of the condensation rate was achieved as compared with the superhydrophobic surface at a subcooling of 13 K. We also demonstrated the enhanced condensation mechanism by a detailed analysis of the condensation process. Our work proposed effective and systematical methods for controlling and optimizing moisture condensation on the patterned surfaces and shed light on application integration of such promising functional surfaces.
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Affiliation(s)
- Xifan Fu
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Qinpeng Zhu
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Denghui Liu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Binghan Liu
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Lintao Kuang
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Yanhui Feng
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Fuqiang Chu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhi Huang
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei Province 430072, China
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22
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Chen F, Wang Y, Tian Y, Zhang D, Song J, Crick CR, Carmalt CJ, Parkin IP, Lu Y. Robust and durable liquid-repellent surfaces. Chem Soc Rev 2022; 51:8476-8583. [DOI: 10.1039/d0cs01033b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This review provides a comprehensive summary of characterization, design, fabrication, and application of robust and durable liquid-repellent surfaces.
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Affiliation(s)
- Faze Chen
- School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
- Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300350, China
| | - Yaquan Wang
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Yanling Tian
- School of Engineering, University of Warwick, Coventry CV4 7AL, UK
| | - Dawei Zhang
- School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
- Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300350, China
| | - Jinlong Song
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Colin R. Crick
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
| | - Claire J. Carmalt
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - Ivan P. Parkin
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - Yao Lu
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
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23
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Chehrghani MM, Abbasiasl T, Sadaghiani AK, Koşar A. Biphilic Surfaces with Optimum Hydrophobic Islands on a Superhydrophobic Background for Dropwise Flow Condensation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13567-13575. [PMID: 34751032 DOI: 10.1021/acs.langmuir.1c01844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Sustaining dropwise condensation is of great importance in many applications, especially in confined spaces. In this regard, superhydrophobic surfaces enhance condensation heat transfer performance due to the discrete droplet formation and rapid removal. On the other hand, droplets tend to nucleate easier and faster on hydrophobic surfaces compared to superhydrophobic ones. To take advantage of the mixed wettability, we fabricated biphilic surfaces and integrated them to small channels to assess their effect on thermal performance in flow condensation in small channels. Hydrophobic islands in the range of 100-900 μm diameter were fabricated using a combination of wet etching, surface functionalization, and physical vapor deposition (PVD) techniques. Condensation experiments were performed in a minichannel with a length, width, and height of 37, 10, and 1 mm, respectively. Here, we report optimum island diameters for the hydrophobic islands in terms of the maximum thermal performance. We show that considering the optimum point for each steam mass flux corresponding to the best heat transfer performance, the condensation heat transfer coefficient is increased by 51, 48, 42, 40, and 36% compared to the plain reference hydrophobic surface for steam mass fluxes of 10, 20, 30, 40, and 50 kg/m2 s, respectively. The optimum island diameters are obtained as 200, 300, 400, 400, and 500 μm, with the ratios of hydrophobic to superhydrophobic surface areas (A* = Ahydrophobic/Asuperhydrophobic) of 3.2, 7.6, 14.4, 14.4, and 24.4%, for steam mass fluxes of 10, 20, 30, 40, and 50 kg/m2 s, respectively. The liquid film forming on the liquid-vapor interface acts as an insulation layer and generates thermal resistance, and bridges appear on the patterned areas and deteriorate the thermal performance. Therefore, it is crucial to characterize the role of droplet mobility on biphilic surfaces to avoid the occurrence of bridging. Through visualization, we demonstrate that the optimum conditions correspond to enhanced droplet nucleation and rapid sweeping regions, where droplet pinning and bridging do not occur. The trends in condensation heat transfer with surface mixed wettability can be divided into three regions: enhanced droplet nucleation and rapid sweeping, highly pinned droplet, and bridging droplet segments. We reveal that the interfacial heat transfer augmentation in the enhanced droplet nucleation and rapid sweeping region is due to both spatial control of droplet nucleation and an increase in the sweeping period. Furthermore, by fitting the experimental data, a correlation for predicting the optimum island diameter for biphilic surfaces is proposed for condensation heat transfer in confined channels, which will be a valuable guideline for engineers and researchers working on the design and development of thermal systems.
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Affiliation(s)
- Mirvahid Mohammadpour Chehrghani
- Faculty of Engineering and Natural Sciences (FENS), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
- Sabanci University Nanotechnology and Application Center (SUNUM), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
| | - Taher Abbasiasl
- Faculty of Engineering and Natural Sciences (FENS), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
- Sabanci University Nanotechnology and Application Center (SUNUM), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
| | - Abdolali Khalili Sadaghiani
- Faculty of Engineering and Natural Sciences (FENS), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
- Sabanci University Nanotechnology and Application Center (SUNUM), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
- Center of Excellence for Functional Surfaces and Interfaces for Nano-Diagnostics (EFSUN), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
| | - Ali Koşar
- Faculty of Engineering and Natural Sciences (FENS), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
- Sabanci University Nanotechnology and Application Center (SUNUM), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
- Center of Excellence for Functional Surfaces and Interfaces for Nano-Diagnostics (EFSUN), Sabanci University, Orhanli, 34956 Tuzla, Istanbul, Turkey
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24
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Abstract
The accumulation of ice will reduce the performance of the base material and lead to all kinds of damage, even a threat to people's life safety. Recent increasing studies suggest that superhydrophobic surfaces (SHSs) originating from nature can remove impacting and condensing droplets from the surface before freezing to subzero temperatures, and it can be seen that hydrophobic/SH coating has good freezing cold resistance. But such anti-icing performances and developments in practical applications are restricted by various factors. In this paper, the mechanism and process of surface icing phenomenon are introduced, as well as how to prevent surface icing on SHS. The development of SH materials in the aspect of anti-icing in recent years is described, and the existing problems in the aspect of anti-icing are analyzed, hoping to provide new research ideas and methods for the research of anti-icing materials.
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Affiliation(s)
- Hua He
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430000, People's Republic of China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - Zhiguang Guo
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430000, People's Republic of China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
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25
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Thomas TM, Sinha Mahapatra P. Condensation of Humid Air on Superhydrophobic Surfaces: Effect of Nanocoatings on a Hierarchical Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12767-12780. [PMID: 34714651 DOI: 10.1021/acs.langmuir.1c01012] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Vapor condensation is a well-known phase-change phenomenon observed in nature as well as in different industrial applications. Superhydrophobic surfaces (SHSs) with low hysteresis can efficiently drain off the condensate and rejuvenate the nucleation sites further. In this work, three distinct SHSs were fabricated by nanocoating three hydrophobic agents, viz., perfluoro-octyl-triethoxy-silane (PFOTS), perfluoro-octanoic-acid (PFOA), and commercial Glaco solution on a hierarchical aluminum surface. The surface morphology of all surfaces was investigated, and its effects on the wetting, droplet departure, and overall heat-transfer coefficient (HTC) during condensation phenomena in the humid air (>95% noncondensable gases) were analyzed. The contact angle hysteresis of all three surfaces was very low (∼5°); however, different wetting behaviors were observed during the condensation, depending on the adhesion of the condensate drop with nanoscale textures in the microcavities. Dropwise condensation (DWC) was observed in silane and Glaco-coated surfaces. A gravity-assisted sweeping mechanism removed the condensate from the silane-coated surface. In contrast, the condensate was ejected out of the plane of the Glaco-coated surface by droplet jumping. The PFOA-coated surface has shown DWC initially and floods in the later stages due to highly pinned condensed droplets. This study reports an enhancement of ∼35 to ∼110% in the HTC for the SHS-exhibiting gravity-assisted sweeping mechanism compared to the droplet-jumping mechanism. The present work will provide substantial insights into the fabrication of efficient hierarchical interfaces for water-energy nexus applications.
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Affiliation(s)
- Tibin M Thomas
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Pallab Sinha Mahapatra
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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26
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Abstract
Superhydrophobic coatings have a huge impact in various applications due to their extreme water-repellent properties. The main novelty of the current research work lies in the development of cheap, stable, superhydrophobic and self-cleaning coatings with extreme water-repellency. In this work, a composite of hydrothermally synthesized alumina (Al2O3), polymethylhydrosiloxane (PMHS) and polystyrene (PS) was deposited on a glass surface by a dip-coating technique. The Al2O3 nanoparticles form a rough structure, and low-surface-energy PHMS enhances the water-repellent properties. The composite coating revealed a water contact angle (WCA) of 171 ± 2° and a sliding angle (SA) of 3°. In the chemical analysis, Al2p, Si2p, O1s, and C1s elements were detected in the XPS survey. The prepared coating showed a self-cleaning property through the rolling action of water drops. Such a type of coating could have various industrial applications in the future.
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27
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Zheng SF, Gross U, Wang XD. Dropwise condensation: From fundamentals of wetting, nucleation, and droplet mobility to performance improvement by advanced functional surfaces. Adv Colloid Interface Sci 2021; 295:102503. [PMID: 34411880 DOI: 10.1016/j.cis.2021.102503] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 01/22/2023]
Abstract
As a ubiquitous vapor-liquid phase-change process, dropwise condensation has attracted tremendous research attention owing to its remarkable efficiency of energy transfer and transformative industrial potential. In recent years, advanced functional surfaces, profiting from great progress in modifying micro/nanoscale features and surface chemistry on surfaces, have led to exciting advances in both heat transfer enhancement and fundamental understanding of dropwise condensation. In this review, we discuss the development of some key components for achieving performance improvement of dropwise condensation, including surface wettability, nucleation, droplet mobility, and growth, and discuss how they can be elaborately controlled as desired using surface design. We also present an overview of dropwise condensation heat transfer enhancement on advanced functional surfaces along with the underlying mechanisms, such as jumping condensation on nanostructured superhydrophobic surfaces, and new condensation characteristics (e.g., Laplace pressure-driven droplet motion, hierarchical condensation, and sucking flow condensation) on hierarchically structured surfaces. Finally, the durability, cost, and scalability of specific functional surfaces are focused on for future industrial applications. The existing challenges, alternative strategies, as well as future perspectives, are essential in the fundamental and applied aspects for the practical implementation of dropwise condensation.
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28
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Foshat S, Jafarpur K, Yaghoubi M. Condensation heat transfer of a hybrid hydrophilic–hydrophobic surface with different arrangements. CHEM ENG COMMUN 2021. [DOI: 10.1080/00986445.2021.1958322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Saeed Foshat
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - Khosrow Jafarpur
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - Mahmood Yaghoubi
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran
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29
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Dewetting transition of water on nanostructured and wettability patterned surfaces: A molecular dynamics study. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116869] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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30
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Tailoring silicon for dew water harvesting panels. iScience 2021; 24:102814. [PMID: 34355147 PMCID: PMC8319802 DOI: 10.1016/j.isci.2021.102814] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/07/2021] [Accepted: 06/28/2021] [Indexed: 11/23/2022] Open
Abstract
Dew water, mostly ignored until now, can provide clean freshwater resources, just by extracting the atmospheric vapor available in surrounding air. Inspired by silicon-based solar panels, the vapor can be harvested by a concept of water condensing panels. Efficient water harvesting requires not only a considerable yield but also a timely water removal from the surface since the very beginning of condensation to avoid the huge evaporation losses. This translates into strict surface properties, which are difficult to simultaneously realize. Herein, we study various functionalized silicon surfaces, including the so-called Black Silicon, which supports two droplet motion modes-out-of-plane jumping and in-plane sweeping, due to its unique surface morphology, synergistically leading to a pioneering combination of above two required characteristics. According to silicon material's scalability, the proposed silicon-based water panels would benefit from existing infrastructures toward dual functions of energy harvesting in daytime and water harvesting in nighttime.
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31
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Cui C, Cao Y, Qi B, Wei J, Yuan J, Wang Y. Convenient and large-scale fabrication of cost-effective superhydrophobic aluminum alloy surface with excellent reparability. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:7810-7820. [PMID: 34129340 DOI: 10.1021/acs.langmuir.1c01123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Superhydrophobic surfaces are widely used in industry and daily life, yet their practical application is limited by their complicated preparation process, high cost, and poor repairability. We propose a low-cost, facile process for preparing superhydrophobic surfaces to address this limitation. Through a simple three-step spraying process, the rough structure was first constructed on the aluminum alloy, and upon modification by modifier, the superhydrophobic aluminum alloy surface was successfully prepared. The effect of the process parameters on wettability was experimentally studied. The results showed that this method can obtain superhydrophobic surfaces with a contact angle of 156.2° and contact angle hysteresis of 7.4° by simply adjusting the etching time and modifier concentration. In addition, it was found that the prepared surface can keep the superhydrophobic property unchanged at 180 °C, showing good thermal stability. When immersed in acetic acid and sodium hydroxide solution, the prepared surface can maintain its superhydrophobicity for about 2 days, showing good chemical stability. Besides, the surface has excellent repairability and can compensate for the short-life defects caused by poor friction resistance. This superhydrophobic surface with a simple preparation process, low cost, and excellent repairable characteristics also has excellent self-cleaning, antifogging, and antifrosting applications.
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Affiliation(s)
- Chenyi Cui
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yafei Cao
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Baojin Qi
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jinjia Wei
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jia Yuan
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Ya Wang
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China
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32
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Wen R, Liu W, Ma X, Yang R. Coupling droplets/bubbles with a liquid film for enhancing phase-change heat transfer. iScience 2021; 24:102531. [PMID: 34113838 PMCID: PMC8170143 DOI: 10.1016/j.isci.2021.102531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Evaporation, boiling, and condensation are fundamental liquid-vapor phase-change heat transfer processes and have been utilized in many conventional and emerging energy systems. Recent advances in the manipulation of interface wetting and heterogeneous nucleation using micro/nano-structured surfaces have enabled exciting two-phase flow dynamics and heat transfer enhancement. However, independently manipulating droplets, bubbles, or liquid films through surface modification has encountered bottlenecks. In this Perspective, we discuss an emerging strategy where droplets/bubbles are coupled with a liquid film to control fluid dynamics for minimizing the thermal resistance between the liquid-vapor interface and solid substrate, thus significantly enhancing the heat transfer performance beyond the state of the art.
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Affiliation(s)
- Rongfu Wen
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Wei Liu
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xuehu Ma
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Ronggui Yang
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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33
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Zhu Z, Zhang Y, Sun DW. Biomimetic modification of freezing facility surfaces to prevent icing and frosting during freezing for the food industry. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.02.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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34
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Xu Y, Zhang G, Luo Z, Qi X, Ma W, Xu C, Liu C, Yao W. Investigation of Dropwise Condensation on a Super-Aligned Carbon Nanotube Mesh-Coated Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:2629-2638. [PMID: 33586440 DOI: 10.1021/acs.langmuir.0c03263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Enhanced vapor condensation is a critical issue for improving the efficiency of energy conversion, thermal management, water recovery, and treatment. Low-energy surfaces incorporating micro/nanoscale roughness have been reported to significantly promote vapor condensation. In this research, the mesh structures of super-aligned carbon nanotube (SACNT) films were prepared by crossing monolayer SACNT films on a copper substrate. Then, the sustaining dropwise condensation was achieved on the SACNT mesh-coated surface. The SACNT mesh-coated surface could obviously enhance the coalescence and sweeping departure of the condensing droplets. Additionally, the measured overall heat transfer coefficient (HTC) of the SACNT mesh-coated surface demonstrated a 36% enhancement compared to that on the bare copper surface. The parallel stacking of SACNT films with different groove structures was also studied, and a 15% enhancement in the HTC was shown as compared with the bare copper surface. Furthermore, we developed a morphology-based model to theoretically analyze the condensation-enhancement mechanism on a SACNT mesh-coated surface. The SACNT surfaces also have advantages of low cost, durability, flexibility, and extensibility. Our findings revealed that the SACNT films could be readily used as vapor condensation-strengthening surfaces, further extending their potential applications to industrial equipment.
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Affiliation(s)
- Yantong Xu
- Department of Space Science Research, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, China
- Beijing Institute of Spacecraft Environment Engineering, Beijing 100094, China
| | - Guang Zhang
- Department of Space Science Research, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, China
| | - Zhiling Luo
- Tsinghua-Foxconn Nanotechnology Research Center and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Xin Qi
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Weigang Ma
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Changjian Xu
- State Key Laboratory of Engine Combustion, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
| | - Changhong Liu
- Tsinghua-Foxconn Nanotechnology Research Center and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wei Yao
- Department of Space Science Research, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, China
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35
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Liu C, Zhao M, Zheng Y, Cheng L, Zhang J, Tee CATH. Coalescence-Induced Droplet Jumping. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:983-1000. [PMID: 33443436 DOI: 10.1021/acs.langmuir.0c02758] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
When two or more droplets coalesce on a superhydrophobic surface, the merged droplet can jump spontaneously from the surface without requiring any external energy. This phenomenon is defined as coalescence-induced droplet jumping and has received significant attention due to its potential applications in a variety of self-cleaning, anti-icing, antifrosting, and condensation heat-transfer enhancement uses. This article reviews the research and applications of coalescence-induced droplet jumping behavior in recent years, including the influence of droplet parameters on coalescence-induced droplet jumping, such as the droplet size, number, and initial velocity, to name a few. The main structure types and influence mechanism of the superhydrophobic substrates for coalescence-induced droplet jumping are described, and the potential application areas of coalescence-induced droplet jumping are summarized and forecasted.
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Affiliation(s)
- Chuntian Liu
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Meirong Zhao
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Yelong Zheng
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Luya Cheng
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Jiale Zhang
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Clarence Augustine T H Tee
- Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
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36
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Xiao Y, Guo Z. Recent advances in biomimetic surfaces inspired by creatures for fog harvesting. NEW J CHEM 2021. [DOI: 10.1039/d1nj03675k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this review, the recent advances in artificial surfaces for fog harvesting are introduced with emphasis on the surfaces and their mechanisms used to enhance water capture and transportation, providing prospects for coping with water shortages.
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Affiliation(s)
- Yisu Xiao
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430000, People's Republic of China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - Zhiguang Guo
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430000, People's Republic of China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
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37
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Tang G, Niu D, Guo L, Xu J. Failure and Recovery of Droplet Nucleation and Growth on Damaged Nanostructures: A Molecular Dynamics Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13716-13724. [PMID: 33147034 DOI: 10.1021/acs.langmuir.0c02809] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The condensate flooding during dropwise condensation causes serious deterioration in heat transfer performance. In this study, the three-dimensional large-scale molecular dynamics simulation is carried out to investigate the droplet state transition from local flooding mode to Wenzel or from Wenzel to Cassie due to the droplet coalescence under the effect of nanostructure size. In particular, the effect of nanostructure breakage on droplet nucleation and growth is discussed to reveal the mechanism of dropwise condensation heat transfer deterioration. As a potential solution, the lubricant-impregnated surface is proposed to recover the preferred Cassie state by regulating the dynamic wetting characteristics of droplets, and thus the detrimental effect of nanostructure breakage could be effectively avoided.
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Affiliation(s)
- Guihua Tang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Dong Niu
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Lin Guo
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jinliang Xu
- Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization, North China Electric Power University, Beijing 102206, China
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38
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Song Z, Lu M, Chen X. Investigation of Dropwise Condensation Heat Transfer on Laser-Ablated Superhydrophobic/Hydrophilic Hybrid Copper Surfaces. ACS OMEGA 2020; 5:23588-23595. [PMID: 32984678 PMCID: PMC7512437 DOI: 10.1021/acsomega.0c01995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/26/2020] [Indexed: 05/10/2023]
Abstract
Heterogeneous surfaces with wetting contrast have gained extensive attention in recent years because of their potential application in condensation heat transfer enhancement. In this work, we engineered superhydrophobic/hydrophilic hybrid (SHH) surfaces on copper substrates via a laser-ablation process. We demonstrated that the as-fabricated SHH surfaces present dropwise condensation behavior; the condensate droplet growth, departure, and heat transfer performance depend strongly on the spacing of the hydrophilic spot. The surface with the hydrophilic spot spacing of 100 μm (SHH100) exhibits the most efficient dropwise condensation in terms of fast droplet growth rate, efficient coalescence-induced droplet departure, as well as enhanced heat transfer coefficient (HTC) compared to the homogeneous superhydrophobic (SHPo) surface. The mechanism underlying the enhanced condensation heat transfer performance is analyzed. A 12% enhancement on condensation HTC was found was found on SHH100 surface compared with the SHPo surface. Our results provide important insights for the design of hybrid surfaces with wetting contrast for enhancing condensation heat transfer performance in many industrial applications.
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39
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Dependencies of Surface Condensation on the Wettability and Nanostructure Size Differences. NANOMATERIALS 2020; 10:nano10091831. [PMID: 32937887 PMCID: PMC7559799 DOI: 10.3390/nano10091831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 11/16/2022]
Abstract
When changing surface wettability and nanostructure size, condensation behavior displays distinct features. In this work, we investigated evaporation on a flat hydrophilic surface and condensation on both hydrophilic and hydrophobic nanostructured surfaces at the nanoscale using molecular dynamics simulations. The simulation results on hydrophilic surfaces indicated that larger groove widths and heights produced more liquid argon atoms, a quicker temperature response, and slower potential energy decline. These three characteristics closely relate to condensation areas or rates, which are determined by groove width and height. For condensation heat transfer, when the groove width was small, the change of groove height had little effect, while change of groove height caused a significant variation in the heat flux with a large groove width. When the cold wall was hydrophobic, the groove height became a significant impact factor, which caused no vapor atoms to condense in the groove with a larger height. The potential energy decreased with the increase of the groove height, which demonstrates a completely opposing trend when compared with hydrophilic surfaces.
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40
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Peng Q, Yan X, Li J, Li L, Cha H, Ding Y, Dang C, Jia L, Miljkovic N. Breaking Droplet Jumping Energy Conversion Limits with Superhydrophobic Microgrooves. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:9510-9522. [PMID: 32689802 DOI: 10.1021/acs.langmuir.0c01494] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Coalescence-induced droplet jumping has the potential to enhance the performance of a variety of applications including condensation heat transfer, surface self-cleaning, anti-icing, and defrosting to name a few. Here, we study droplet jumping on hierarchical microgrooved and nanostructured smooth superhydrophobic surfaces. We show that the confined microgroove structures play a key role in tailoring droplet coalescence hydrodynamics, which in turn affects the droplet jumping velocity and energy conversion efficiency. We observed self-jumping of individual deformed droplets within microgrooves having maximum surface-to-kinetic energy conversion efficiency of 8%. Furthermore, various coalescence-induced jumping modes were observed on the hierarchical microgrooved superhydrophobic surface. The microgroove structure enabled high droplet jumping velocity (≈0.74U) and energy conversion efficiency (≈46%) by enabling the coalescence of deformed droplets in microgrooves with undeformed droplets on adjacent plateaus. The jumping velocity and energy conversion efficiency enhancements are 1.93× and 6.67× higher than traditional coalescence-induced droplet jumping on smooth superhydrophobic surfaces. This work not only demonstrates high droplet jumping velocity and energy conversion efficiency but also demonstrates the key role played by macroscale structures on coalescence hydrodynamics and elucidates a method to further control droplet jumping physics for a plethora of applications.
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Affiliation(s)
- Qi Peng
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Xiao Yan
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Jiaqi Li
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Longnan Li
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Hyeongyun Cha
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Yi Ding
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Chao Dang
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Li Jia
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, United States
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
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41
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Wang X, Xu B, Chen Z, Yang Y, Cao Q. Lattice Boltzmann Modeling of Condensation Heat Transfer on Downward-Facing Surfaces with Different Wettabilities. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:9204-9214. [PMID: 32660253 DOI: 10.1021/acs.langmuir.0c01469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The model of vapor condensation heat transfer on downward-facing surfaces with different wettabilities is built by a two-dimensional (2D) lattice Boltzmann method. Dynamic evolution of condensate microdroplets on different wettability surfaces is simulated and the influence on heat transfer performance is analyzed. Moreover, the mechanism of a heterogeneous wettability surface enhancing condensation heat transfer is explored by investigating the condensate behaviors in the process of condensation. The numerical results indicate that as the contact angle of the homogeneous wettability surface increases, the initial nucleation time of the condensate is prolonged, while the departure time of the condensate is reduced significantly. The temperature adjacent to the gas-liquid interface, especially in the three-phase contact line region, is much higher than elsewhere due to the release of latent heat during condensation. Coalescence and detachment behaviors of condensate droplets cause the average heat flux to fluctuate locally with time. For the hybrid wettability surface, if the proportion of hydrophobic regions is small, the condensation heat transfer performance will be deteriorated. However, increasing the hydrophobic-hydrophilic ratio has a positive effect on enhancing heat transfer. It is found that a critical hydrophobic-hydrophilic ratio exists to optimize the heat transfer performance. For the gradient wettability surface, directional migration induced by capillary force facilitates the removal of condensate droplets, thereby enhancing the condensation heat transfer. Furthermore, a larger wetting gradient benefits to further improve the heat transfer performance. The results are valuable for optimally designing the heat transfer enhancement of vapor condensation on functionalized surfaces with heterogeneous wettability.
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Affiliation(s)
- Xin Wang
- School of Energy and Environment, Southeast University, Nanjing 210096, P. R. China
| | - Bo Xu
- School of Energy and Environment, Southeast University, Nanjing 210096, P. R. China
- Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology, School of Energy and Environment, Southeast University, Nanjing 210096, P. R. China
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing210096, P. R. China
| | - Zhenqian Chen
- School of Energy and Environment, Southeast University, Nanjing 210096, P. R. China
- Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology, School of Energy and Environment, Southeast University, Nanjing 210096, P. R. China
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing210096, P. R. China
| | - Yang Yang
- Engineering and Technology Center For Space Applications, Chinese Academy of Sciences, Beijing 100094, P. R. China
| | - Qian Cao
- Engineering and Technology Center For Space Applications, Chinese Academy of Sciences, Beijing 100094, P. R. China
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42
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Mohammadian B, Annavarapu RK, Raiyan A, Nemani SK, Kim S, Wang M, Sojoudi H. Delayed Frost Growth on Nanoporous Microstructured Surfaces Utilizing Jumping and Sweeping Condensates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6635-6650. [PMID: 32418428 DOI: 10.1021/acs.langmuir.0c00413] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Self-propelled jumping of condensate droplets (dew) enables their easy and efficient removal from surfaces and is essential for enhancing the condensation heat transfer coefficient and for delaying the frost growth rate on supercooled surfaces. Here, we report the droplet-jumping phenomenon using nanoporous vertically aligned carbon nanotube (VA-CNT) microstructures grown on smooth silicon substrates and coated with poly-(1H, 1H, 2H, 2H-perfluorodecylacrylate) (pPFDA). We also report droplet-sweeping phenomenon on horizontally mounted surfaces, concluding that the frost surface coverage area and the frost growth rates observed with the droplet-sweeping phenomenon are much lower than those that are observed with the droplet-jumping phenomenon alone. We also investigate the fundamentals of droplet-jumping and the frost growth phenomena using line-shaped, hollow-cylindrical, and cylindrical microstructures, comparing the frost surface coverage area and the ice-bridging times during condensation-frosting, prolonged condensation-frosting, and direct-frosting. We find that the closely spaced thin line-shaped microstructures and hollow-cylindrical microstructures are optimal for frost coverage reduction because of their ability to exhibit droplet-jumping and droplet-sweeping phenomena. We observe that adding nonuniform roughness on top of the microstructures leads to jumping-associated droplet-sweeping on supercooled surfaces. Here, we report the evaporation of an already frozen droplet because of freezing of a supercooled condensate droplet in its close vicinity, enabling the Cassie-Baxter state frost growth and enhancing defrosting efficiency. Finally, we discuss the dynamic defrosting behavior of the pPFDA-coated VA-CNT microstructures, concluding that the small gaps (spacings) between the microstructures not only enable dewetting transitions of droplets but also promote the Cassie-Baxter state frost formation.
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Affiliation(s)
- Behrouz Mohammadian
- Department of Mechanical Industrial and Manufacturing Engineering (MIME), The University of Toledo, 4006 Nitschke Hall, Toledo, Ohio 43606, United States
| | - Rama Kishore Annavarapu
- Department of Mechanical Industrial and Manufacturing Engineering (MIME), The University of Toledo, 4006 Nitschke Hall, Toledo, Ohio 43606, United States
| | - Asif Raiyan
- Department of Mechanical Industrial and Manufacturing Engineering (MIME), The University of Toledo, 4006 Nitschke Hall, Toledo, Ohio 43606, United States
| | - Srinivasa Kartik Nemani
- Department of Mechanical Industrial and Manufacturing Engineering (MIME), The University of Toledo, 4006 Nitschke Hall, Toledo, Ohio 43606, United States
| | - Sanha Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Minghui Wang
- Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Hossein Sojoudi
- Department of Mechanical Industrial and Manufacturing Engineering (MIME), The University of Toledo, 4006 Nitschke Hall, Toledo, Ohio 43606, United States
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Wang R, Wu F, Xing D, Yu F, Gao X. Density Maximization of One-Step Electrodeposited Copper Nanocones and Dropwise Condensation Heat-Transfer Performance Evaluation. ACS APPLIED MATERIALS & INTERFACES 2020; 12:24512-24520. [PMID: 32363858 DOI: 10.1021/acsami.0c05224] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Currently, it is still a great challenge to obtain copper-based high-efficient dropwise condensation heat transfer (CHT) interfaces via template-free electrodepositing technologies. Here, we report that the density of template-free electrodeposited copper nanocones can maximally reach 1.5 × 106/mm2 by the synergistic control of substrate surface roughness, poly(ethylene glycol) (PEG) molecular weight, and PEG concentration. After thiol modification, the densely packed copper nanocone samples can present low-adhesive superhydrophobicity and condensate microdrop self-jumping function at ambient environment. Condensation heat and mass transfer characterizations show that the CHT coefficient of copper surfaces can maximally enhance 98% for 20 °C vapor and 51% for 40 °C vapor by in situ growth of superhydrophobic densely packed copper nanocones. Although the dropwise condensation mode can change from the jumping mode to the mixed jumping and sweeping mode and the shedding-off mode along with the increase of surface subcooling and vapor temperature, the CHT performance of the nanosample is still superior to that of the contrast flat hydrophobic surface during the whole testing range of surface subcooling. As vapor temperature increases to 80 °C, the CHT performance of the nanosample is inferior to that of the contrast sample. The CHT enhancement under low-temperature vapor should be ascribed to the enhancement of small-drop mass transfer ability caused by low-adhesive superhydrophobicity nature of nanosample surfaces. Their performance degradation mainly results from increased drop-drop drag force along with the increase of surface subcooling and vapor temperature. In sharp contrast, the CHT deterioration under high-temperature vapor should be ascribed to larger drop-surface adhesion and drop-drop drag force. The former is caused by vapor penetration, whereas the latter is caused by the dramatically increased nucleation density and growth rate of condensates. These findings would help design and develop copper-based high-efficiency condensation heat transfer interfaces.
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Affiliation(s)
- Rui Wang
- Functional Materials and Interfaces Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Feifei Wu
- Functional Materials and Interfaces Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Dandan Xing
- Functional Materials and Interfaces Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Fanfei Yu
- Functional Materials and Interfaces Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Xuefeng Gao
- Functional Materials and Interfaces Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, P. R. China
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Zhao G, Zou G, Wang W, Geng R, Yan X, He Z, Liu L, Zhou X, Lv J, Wang J. Rationally designed surface microstructural features for enhanced droplet jumping and anti-frosting performance. SOFT MATTER 2020; 16:4462-4476. [PMID: 32323690 DOI: 10.1039/d0sm00436g] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The accretion of frost on heat exchanging surfaces through the freezing of condensed water in cold and humid environments significantly reduces the operating efficiency of air-source heat pumps, refrigerators and other cryogenic equipment. The construction of hierarchical micro-nanostructured SHSs, with the ability to timely remove condensed water before freezing via self-propelled droplet jumping, serves as a promising anti-frosting strategy. However, the actual relationship between microstructural features and water removal capability through droplet jumping is still not clear, hindering the further optimization of anti-frosting SHSs. Herein, a series of aluminum SHSs with different micro-cone arrays is designed and fabricated via ultrafast laser processing and chemical etching. The effect of microstructural features on water removal capability is elucidated by statistically analyzing the condensation process. As compared to nanostructured SHSs with the micro-cone size ranging from 10 to 40 μm, the water removal through droplet jumping is remarkably enhanced from 3.42 g m-2 to as much as 13.91 g m-2 over 10 minutes of condensation experiments due to the effective transition of condensed microdroplets from the initial high-adhesion partial wetting (PW) state to low-adhesion Cassie state, leading to significantly reduced water accumulation and improved anti-frosting performance. However, a further increase in the micro-cone size decreased the water removal amount due to greater droplet adhesion to the surface, which results in higher chances for immobile coalescence and the formation of large droplets. Herein, by rationally tuning the size scale of the structured micro-cones, the optimal SHSs display the least water accumulation and render excellent frosting delay of over 90 minutes under simulated harsh operating conditions.
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Affiliation(s)
- Guanlei Zhao
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Tsinghua University, Beijing 100084, China. and Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Guisheng Zou
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Tsinghua University, Beijing 100084, China.
| | - Wengan Wang
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Tsinghua University, Beijing 100084, China.
| | - Ruikun Geng
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Tsinghua University, Beijing 100084, China.
| | - Xiao Yan
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 10084, China
| | - Zhiyuan He
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Lei Liu
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Tsinghua University, Beijing 100084, China.
| | - Xin Zhou
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jianyong Lv
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Jianjun Wang
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and School of Future Technology, University of Chinese Academy of Sciences, Beijing 100190, China
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Zhao G, Zou G, Wang W, Geng R, Yan X, He Z, Liu L, Zhou X, Lv J, Wang J. Competing Effects between Condensation and Self-Removal of Water Droplets Determine Antifrosting Performance of Superhydrophobic Surfaces. ACS APPLIED MATERIALS & INTERFACES 2020; 12:7805-7814. [PMID: 31972085 DOI: 10.1021/acsami.9b21704] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Preventing condensation frosting is crucial for air conditioning units, refrigeration systems, and other cryogenic equipment. Coalescence-induced self-propelled jumping of condensed microdroplets on superhydrophobic surfaces serves as a favorable strategy against condensation frosting. In previous reports, efforts were dedicated to enhance the efficiency of self-propelled jumping by constructing appropriate surface structures on superhydrophobic surfaces. However, the incorporation of surface structures results in larger area available for condensation to occur, leading to an increase in total amount of condensed water on the surface and partially counteracts the effect of promoted jumping on removing condensed water from the surface. In this paper, we focus on the competing effects between condensing and self-propelled jumping on promoting and preventing water accumulation, respectively. A series of micro- and nanostructured superhydrophobic surfaces are designed and prepared. The condensation process and self-propelled jumping behavior of microdroplets on the surfaces are investigated. Thousands of jumping events are statistically analyzed to acquire a comprehensive understanding of antifrosting potential of superhydrophobic surfaces with self-propelled jumping of condensed microdroplets. Further frosting experiments shows that the surface with the lowest amount of accumulated water exhibits the best antifrosting performance, which validates our design strategy. This work offers new insights into the rational design and fabrication of antifrosting materials.
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Affiliation(s)
- Guanlei Zhao
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China , Tsinghua University , Beijing 100084 , China
- Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , China
| | - Guisheng Zou
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China , Tsinghua University , Beijing 100084 , China
| | - Wengan Wang
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China , Tsinghua University , Beijing 100084 , China
| | - Ruikun Geng
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China , Tsinghua University , Beijing 100084 , China
| | - Xiao Yan
- Institute of Nuclear and New Energy Technology , Tsinghua University , Beijing , 10084 , China
| | - Zhiyuan He
- Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , China
| | - Lei Liu
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China , Tsinghua University , Beijing 100084 , China
| | - Xin Zhou
- School of Physical Sciences , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Jianyong Lv
- Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , China
| | - Jianjun Wang
- Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , China
- School of Future Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
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Seo D, Shim J, Moon B, Lee K, Lee J, Lee C, Nam Y. Passive Anti-Flooding Superhydrophobic Surfaces. ACS APPLIED MATERIALS & INTERFACES 2020; 12:4068-4080. [PMID: 31891474 DOI: 10.1021/acsami.9b17943] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Superhydrophobic (SHPo) surfaces can provide high condensation heat transfer due to facilitated droplet removal. However, such high performance has been limited to low supersaturation conditions due to surface flooding. Here, we quantify flooding resistance defined as the rate of increase in the fraction of water-filled cavities with respect to the supersaturation level. Based on the quantitative understanding of surface flooding, we suggest effective anti-flooding strategies through tailoring the nanoscale coating heterogeneity and structure length scale. Experimental verification is conducted using CuO nanostructures having different length scales combined with hydrophobic coatings with different nanoscale heterogeneities. The proposed anti-flooding SHPo can provide a ∼130% enhanced average heat transfer coefficient with ∼14% larger supersaturation range for droplet jumping compared to a previous CuO SHPo. The proposed anti-flooding parameter and the scalable SHPo will help develop high-performance condensers for real-world applications operating in a wide range of supersaturation levels.
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Affiliation(s)
- Donghyun Seo
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
| | - Jaehwan Shim
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
| | - Byungyun Moon
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
| | - Kyungjun Lee
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
| | - Jooyoung Lee
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
| | - Choongyeop Lee
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
| | - Youngsuk Nam
- Department of Mechanical Engineering , Kyung Hee University , Yongin 446-701 , Korea
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Abstract
This review starts with the main process of fog collection and then analyzes the influencing factors that affect the efficiency of fog collection.
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Affiliation(s)
- Xing Tang
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials
- Hubei University
- Wuhan 430062
- People's Republic of China
- State Key Laboratory of Solid Lubrication
| | - Zhiguang Guo
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials
- Hubei University
- Wuhan 430062
- People's Republic of China
- State Key Laboratory of Solid Lubrication
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Li J, Fu W, Zhang B, Zhu G, Miljkovic N. Ultrascalable Three-Tier Hierarchical Nanoengineered Surfaces for Optimized Boiling. ACS NANO 2019; 13:14080-14093. [PMID: 31808673 DOI: 10.1021/acsnano.9b06501] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nanostructure-enhanced pool and flow boiling has the potential to increase the efficiency of a plethora of applications. Past studies have developed well-ordered, nonscalable structures to study the fundamental limitations of boiling such as bubble nucleation, growth, and departure, often in a serial manner without global optimization. Here, we develop a highly scalable, conformal, cost-effective, rapid, and tunable three-tier hierarchical surface deposition technique capable of holistically creating micropores, microscale dendritic clusters, and nanoparticles on arbitrary surfaces. We use this technique to investigate the pool boiling heat transfer performance with focus on the bubble departure diameter and frequency. By tuning the structure length scale, the pool boiling characteristics were optimized through a multipronged approach, including increasing nucleation site density (micropores), regulating bubble evolution behavior (dendritic structures), improving surface wickability (nanoscale particles and channels), and separating liquid and vapor pathways (micropores and micro/nanochannels). Ultrahigh critical heat fluxes (CHF) ≈400 W/cm2 were obtained, corresponding to an enhancement of ≈245% compared to smooth copper surfaces. To study in situ bubble departure and coalescence dynamics, we developed and used high-magnification in-liquid endoscopy. Our work reveals the existence of a linear relationship between the bubble departure diameter/frequency near the onset of nucleate boiling and CHF enhancement. Our study not only develops a highly scalable, conformal, and rapid micro/nanostructuring technique, it outlines design guidelines for the holistic optimization of boiling heat transfer for energy and water applications.
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Affiliation(s)
- Jiaqi Li
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
| | - Wuchen Fu
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
| | - Bohan Zhang
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
| | - Gaohua Zhu
- Materials Research Department , Toyota Research Institute of North America , Ann Arbor , Michigan 48105 , United States
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
- Department of Electrical and Computer Engineering , University of Illinois , Urbana , Illinois 61801 , United States
- Materials Research Laboratory , University of Illinois , Urbana , Illinois 61801 , United States
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER) , Kyushu University , 744 Moto-oka Nishi-ku , Fukuoka 819-0395 , Japan
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Sharma V, Yiannacou K, Karjalainen M, Lahtonen K, Valden M, Sariola V. Large-scale efficient water harvesting using bioinspired micro-patterned copper oxide nanoneedle surfaces and guided droplet transport. NANOSCALE ADVANCES 2019; 1:4025-4040. [PMID: 36132092 PMCID: PMC9418429 DOI: 10.1039/c9na00405j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/03/2019] [Indexed: 05/24/2023]
Abstract
As the Earth's atmosphere contains an abundant amount of water as vapors, a device which can capture a fraction of this water could be a cost-effective and practical way of solving the water crisis. There are many biological surfaces found in nature which display unique wettability due to the presence of hierarchical micro-nanostructures and play a major role in water deposition. Inspired by these biological microstructures, we present a large scale, facile and cost-effective method to fabricate water-harvesting functional surfaces consisting of high-density copper oxide nanoneedles. A controlled chemical oxidation approach on copper surfaces was employed to fabricate nanoneedles with controlled morphology, assisted by bisulfate ion adsorption on the surface. The fabricated surfaces with nanoneedles displayed high wettability and excellent fog harvesting capability. Furthermore, when the fabricated nanoneedles were subjected to hydrophobic coating, these were able to rapidly generate and shed coalesced droplets leading to further increase in fog harvesting efficiency. Overall, ∼99% and ∼150% increase in fog harvesting efficiency was achieved with non-coated and hydrophobic layer coated copper oxide nanoneedle surfaces respectively when compared to the control surfaces. As the transport of the harvested water is very important in any fog collection system, hydrophilic channels inspired by leaf veins were made on the surfaces via a milling technique which allowed an effective and sustainable way to transport the captured water and further enhanced the water collection efficiency by ∼9%. The system presented in this study can provide valuable insights towards the design and fabrication of fog harvesting systems, adaptable to arid or semi-arid environmental conditions.
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Affiliation(s)
- Vipul Sharma
- Faculty of Medicine and Health Technology, Tampere University Korkeakoulunkatu 3 33720 Tampere Finland
| | - Kyriacos Yiannacou
- Faculty of Medicine and Health Technology, Tampere University Korkeakoulunkatu 3 33720 Tampere Finland
| | - Markus Karjalainen
- Faculty of Medicine and Health Technology, Tampere University Korkeakoulunkatu 3 33720 Tampere Finland
| | - Kimmo Lahtonen
- Faculty of Engineering and Natural Sciences, Tampere University P.O. Box 692 FI-33014 Finland
| | - Mika Valden
- Faculty of Engineering and Natural Sciences, Tampere University P.O. Box 692 FI-33014 Finland
| | - Veikko Sariola
- Faculty of Medicine and Health Technology, Tampere University Korkeakoulunkatu 3 33720 Tampere Finland
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50
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Wang R, Jakhar K, Antao DS. Unified Modeling Framework for Thin-Film Evaporation from Micropillar Arrays Capturing Local Interfacial Effects. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:12927-12935. [PMID: 31525296 DOI: 10.1021/acs.langmuir.9b02048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Thin-film evaporation from micropillar array porous media has gained attention in a number of fields including energy conversion and thermal management of electronics. Performance in these applications is enhanced by leveraging the geometries of the micropillar arrays to both optimize flow through these arrays via capillary pumping and increase the curved liquid-vapor interface (meniscus) area for active phase-change heat transfer. In this work, we present a unified semianalytical modeling framework to predict the dry-out heat flux accurately for thin-film evaporation from micropillar arrays with the precise prediction of (i) the pressure profile along the wick achieved by discretizing the porous media domain and (ii) the local permeability that depends on the local meniscus shape. We validate the permeability model with 3D numerical simulations and verify the accuracy of the thin-film evaporation modeling framework with available experimental data from the literature. We emphasize the importance of predicting an accurate liquid-vapor interface shape for the prediction accuracy of both the permeability and the associated governing equations for liquid propagation and phase-change heat transfer through porous materials. This modeling framework is an accurate non-CFD-based methodology for predicting the dry-out heat flux during thin-film evaporation from micropillar arrays and will serve as a general framework for modeling steady liquid-vapor phase-change processes (evaporation and condensation) in porous media.
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Affiliation(s)
- Ruisong Wang
- J. Mike Walker '66 Department of Mechanical Engineering , Texas A&M University , College Station , Texas 77843-3123 , United States
| | - Karan Jakhar
- J. Mike Walker '66 Department of Mechanical Engineering , Texas A&M University , College Station , Texas 77843-3123 , United States
| | - Dion S Antao
- J. Mike Walker '66 Department of Mechanical Engineering , Texas A&M University , College Station , Texas 77843-3123 , United States
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