1
|
Liu M, Hua J, Du X. Smart materials for light control of droplets. NANOSCALE 2024. [PMID: 38624048 DOI: 10.1039/d3nr05593k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Droplet manipulation plays a critical role in both fundamental research and practical applications, especially when combined with smart materials and external fields to achieve multifunctional droplet manipulation. Light control of droplets has emerged as a significant and widely used strategy, driven primarily by photochemistry, photomechanics, light-induced Marangoni effects, and light-induced electric effects. This approach allowing for droplet manipulation with high spatial and temporal resolution, all while maintaining a remote and non-contact mode of operation. This review aims to provide a comprehensive overview of the mechanisms underlying light control of droplets, the design of smart materials for this purpose, and the diverse range of applications enabled by this technique. These applications include merging, splitting, releasing, forwarding, backward movement, and rotation of droplets, as well as chemical reactions, droplet robots, and microfluidics. By presenting this information, we aim to establish a unified framework that guides the sustainable development of light control of droplets. Additionally, this review addresses the challenges associated with light control of droplets and suggests potential directions for future development.
Collapse
Affiliation(s)
- Meijin Liu
- Institute of Biomedical & Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
| | - Jiachuan Hua
- Institute of Biomedical & Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
| | - Xuemin Du
- Institute of Biomedical & Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
| |
Collapse
|
2
|
Zhang Y, Wang L, Zhao X, Yang H, Liu J, Wang J. A simple fabrication of liquid-like polydimethylsiloxane coating for resisting ice adhesion. J Chem Phys 2024; 160:084703. [PMID: 38391021 DOI: 10.1063/5.0188199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/05/2024] [Indexed: 02/24/2024] Open
Abstract
The rapid realization of efficient anti-icing coatings on diverse substrates is of vital value for practical applications. However, current approaches for rapid preparations of anti-icing coatings are still deficient regarding their surface universality and accessibility. Here, we report a simple processing approach to rapidly form icephobic liquid-like polydimethylsiloxane (PDMS) brushes on various substrates, including metals, ceramics, glass, and plastics. A poly(dimethylsiloxane), trimethoxysilane is applied as a reactant under the catalysis of a minimal amount of acid formed by hydrolysis of dichlorodimethylsilane. With such an advantage, this approach is approved to be applicable of coating metal surfaces with less corrosion. The distinctive flexibility of the PDMS chains provides a liquid-like property to the coating showing low contact angle hysteresis and ice adhesion strength. Notably, the ice adhesion strength remains similar across a wide temperature window, from -70 to -10 °C, with a value of 18.4 kPa. The PDMS brushes demonstrate perfect capability for resisting acid and alkali corrosions, ultra-violet degradation, and even tens of icing/deicing cycles. Moreover, the liquid-like coating can also form at supercooling conditions, such as -20 °C, and shows an outstanding anti-icing/deicing performance, which meets the in situ coating reformation requirement under extreme conditions when it is damaged. This instantly forming anti-icing material will benefit from resisting instantaneous ice accretion on surfaces under extremely cold conditions.
Collapse
Affiliation(s)
- Yixuan Zhang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Lei Wang
- Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Xueying Zhao
- Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Huige Yang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Jie Liu
- Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jianjun Wang
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| |
Collapse
|
3
|
Mai C, Lv C, Yang L, Guo Y, Zhao L, Jiang Y, Zhang H. Preparation of superhydrophobic surface from raspberry like particles of bifunctional polyssesquioxane. J Appl Polym Sci 2023. [DOI: 10.1002/app.53902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Affiliation(s)
- Chongyang Mai
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
| | - Chengcheng Lv
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
| | - Li Yang
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
| | - Yawen Guo
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
| | - Lielun Zhao
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
| | - Yan Jiang
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
- Jiangsu Chenguang Paint Co., Ltd Changzhou 213164 China
| | - Hongwen Zhang
- School of Material Science and Engineering, Changzhou University Changzhou 213164 China
| |
Collapse
|
4
|
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.
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Wei W, Li M, Chen Y. Flexible Broadband Light Absorbers with a Superhydrophobic Surface Fabricated by Ultraviolet-assisted Nanoimprint Lithography. Chem Res Chin Univ 2022. [DOI: 10.1007/s40242-022-2044-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
7
|
Cheng Y, Wang M, Sun J, Liu M, Du B, Liu Y, Jin Y, Wen R, Lan Z, Zhou X, Ma X, Wang Z. Rapid and Persistent Suction Condensation on Hydrophilic Surfaces for High-Efficiency Water Collection. NANO LETTERS 2021; 21:7411-7418. [PMID: 34176267 DOI: 10.1021/acs.nanolett.1c01928] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Water collection by dew condensation emerges as a sustainable solution to water scarcity. However, the transient condensation process that involves droplet nucleation, growth, and transport imposes conflicting requirements on surface properties. It is challenging to satisfy all benefits for different condensation stages simultaneously. By mimicking the structures and functions of moss Rhacocarpus, here, we report the attainment of dropwise condensation for efficient water collection even on a hydrophilic surface gated by a liquid suction mechanism. The Rhacocarpus-inspired porous surface (RIPS), which possesses a three-level wettability gradient, facilitates a rapid, directional, and persistent droplet suction. Such suction condensation enables a low nucleation barrier, frequent surface refreshing, and well-defined maximum droplet shedding radius simultaneously. Thus, a maximum ∼160% enhancement in water collection performance compared to the hydrophobic surface is achieved. Our work provides new insights and a design route for developing engineered materials for a wide range of water-harvesting and phase-change heat-transfer applications.
Collapse
Affiliation(s)
- Yaqi Cheng
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Mingmei Wang
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Jing Sun
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Minjie Liu
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Bingang Du
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Yuanbo Liu
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Yuankai Jin
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Rongfu Wen
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Zhong Lan
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Xiaofeng Zhou
- Shanghai Key Laboratory of Multidimensional Information Processing, School of Communication and Electronic Engineering, East China Normal University, Shanghai 200241, China
| | - Xuehu Ma
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Zuankai Wang
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
- Research Center for Nature-Inspired Engineering, City University of Hong Kong, Hong Kong 999077, China
| |
Collapse
|
8
|
Liu C, Sun Y, Huanng J, Guo Z, Liu W. External-field-induced directional droplet transport: A review. Adv Colloid Interface Sci 2021; 295:102502. [PMID: 34390884 DOI: 10.1016/j.cis.2021.102502] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/18/2021] [Accepted: 08/02/2021] [Indexed: 02/08/2023]
Abstract
Directional transport of fluids is crucial for vital activities of organisms and numerous industrial applications. This process has garnered widespread research attention due to the wide breadth of flexible applications such as medical diagnostics, drug delivery, and digital microfluidics. The rational design of functional surfaces that can achieve the subtle control of liquid behavior. Previous studies were mainly dependent on the special asymmetric structures, which inevitably have the problem of slow transport speed and short distance. To improve controllability, researchers have attempted to use external fields, such as thermal, light, electric fields, and magnetic fields, to achieve controllable droplet transport. On the fundamental side, much of their widespread applicably is due to the degree of control over droplet transport. This review provides an overview of recent progress in the last three years toward the transport of droplets with different mechanisms induced by various external stimuli, including light, electric, thermal, and magnetic field. First, the relevant basic theory and typical induced gradient for directional liquid transport are illustrated. We will then review the latest advances in the external-field-induced directional transport. Moreover, the most emerging applications such as digital microfluidics, harvesting of energy and water, heat transfer, and oil/water separation are also presented. Finally, we will outline possible future perspectives to attract more researchers interest and promote the development of this field.
Collapse
|
9
|
Baba S, Sawada K, Tanaka K, Okamoto A. Condensation Behavior of Hierarchical Nano/Microstructured Surfaces Inspired by Euphorbia myrsinites. ACS APPLIED MATERIALS & INTERFACES 2021; 13:32332-32342. [PMID: 34190527 DOI: 10.1021/acsami.1c01400] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In nature, many extant species exhibit functionalized surface structures during evolution. In particular, wettability affects the functionalization of the surface, and nano/microstructures have been found to enable functions, such as droplet jumping, thereby making self-cleaning, antifog, antibacterial, and antireflection surfaces. Important efforts are underway to understand the surface structure of plant leaves and establish rational design tools for the development of new engineering materials. In this study, we focused on the hierarchical nano/microstructure of the leaves of Euphorbia myrsinites (hereinafter, E. myrsinites), which has a hierarchical shape with microsized papillae, covered with nanosized protruding wax, and observed the condensation behavior on the leaf surface. Si is vertically etched via reactive ion etching (RIE) to artificially mimic the hierarchical nano/microstructures on the leaves of E. myrsinites. We made four types of artificial hierarchical structures, with micropillars having pillar diameters of 5.6 and 16 μm (pillar spacing of 20 and 40 μm, respectively) and heights of 6.5 and 19.5 μm, and nanopillars formed on the surface. The optical observation with a microscope revealed a very high density of condensed droplets on the artificial surface and a stable jumping behavior of droplets of 10 μm or more. Furthermore, in the samples with a micropillar diameter of 5.6 μm and a micropillar height of 19.5 μm, the droplets that had jumped and fallen thereupon bounced off, thereby preventing reattachment. As a result, no droplets of 35 μm or more could exist even after 10 min. In addition, it was clear that a small underlying droplet of less than 10 μm was generated at the bottom of the relatively large secondary droplet existing on the large micropillar of 16 μm, and a frequent coalescence of the droplets occurred. This study revealed the phenomenon of condensation on the surface of plants as well as made it possible to improve the heat exchange process by significantly promoting the heat transfer of condensation using artificial surfaces.
Collapse
Affiliation(s)
- Soumei Baba
- Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba-shi, Ibaraki 305-8564, Japan
| | - Kenichiro Sawada
- Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-0233, Japan
| | - Kohsuke Tanaka
- Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba-shi, Ibaraki 305-8505, Japan
| | - Atsushi Okamoto
- Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba-shi, Ibaraki 305-8505, Japan
| |
Collapse
|
10
|
Yan X, Qin Y, Chen F, Zhao G, Sett S, Hoque MJ, Rabbi KF, Zhang X, Wang Z, Li L, Chen F, Feng J, Miljkovic N. Laplace Pressure Driven Single-Droplet Jumping on Structured Surfaces. ACS NANO 2020; 14:12796-12809. [PMID: 33052666 DOI: 10.1021/acsnano.0c03487] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Droplet transport on, and shedding from, surfaces is ubiquitous in nature and is a key phenomenon governing applications including biofluidics, self-cleaning, anti-icing, water harvesting, and electronics thermal management. Conventional methods to achieve spontaneous droplet shedding enabled by surface-droplet interactions suffer from low droplet transport velocities and energy conversion efficiencies. Here, by spatially confining the growing droplet and enabling relaxation via rationally designed grooves, we achieve single-droplet jumping of micrometer and millimeter droplets with dimensionless jumping velocities v* approaching 0.95, significantly higher than conventional passive approaches such as coalescence-induced droplet jumping (v* ≈ 0.2-0.3). The mechanisms governing single-droplet jumping are elucidated through the study of groove geometry and local pinning, providing guidelines for optimized surface design. We show that rational design of grooves enables flexible control of droplet-jumping velocity, direction, and size via tailoring of local pinning and Laplace pressure differences. We successfully exploit this previously unobserved mechanism as a means for rapid removal of droplets during steam condensation. Our study demonstrates a passive method for fast, efficient, directional, and surface-pinning-tolerant transport and shedding of droplets having micrometer to millimeter length scales.
Collapse
Affiliation(s)
- Xiao Yan
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yimeng Qin
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Feipeng Chen
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Guanlei Zhao
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Soumyadip Sett
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Muhammad Jahidul Hoque
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Kazi Fazle Rabbi
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Xueqian Zhang
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Zi Wang
- 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
| | - Feng Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Jie Feng
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - 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
| |
Collapse
|
11
|
Zhang T, Zhang Z. Droplet Growth Model for Dropwise Condensation on Concave Hydrophobic Surfaces. ACS OMEGA 2020; 5:22560-22567. [PMID: 32923815 PMCID: PMC7482238 DOI: 10.1021/acsomega.0c03187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
In this paper, mathematical models for predicting the droplet growth and droplet distribution of dropwise condensation on hydrophobic concave surface are developed and a theoretical analysis of the results of the model simulation is made. Under the assumptions of the Cassie-Baxter wetting mode and the consideration of noncondensable gases, the droplet growth model is not only established by heat transfer through a single droplet but also considered the thermal conductive resistance of the surface promoting layer. In addition, a droplet distribution model has been built based on the population balance theory. According to the calculation, the main thermal resistance in the droplet growth process is the conductive resistance inside the droplet. With the increase of contact angle, the above-mentioned thermal resistance increases; thus, the higher the hydrophobicity is, the slower the droplet growth and the less the droplet density are. Besides, the lower the temperature of the condensing surface is, the faster the droplets grow and the less the droplet density is. The models provide a mathematical tool for predicting the droplet radius at the initial stage of dewing on the concave surface and contribute to the design of functional surfaces in the field of water harvesting.
Collapse
|
12
|
Baba S, Sawada K, Tanaka K, Okamoto A. Dropwise Condensation on a Hierarchical Nanopillar Structured Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:10033-10042. [PMID: 32787030 DOI: 10.1021/acs.langmuir.0c00950] [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
Nanopillar structure processing has been performed on condensation surfaces to control wettability and achieve a high heat transfer coefficient via dropwise condensation and jumping droplets. Modified dry etching was performed using gold (Au) nanoparticles generated by annealing Au as a mask. High-aspect-ratio nanopillar processing was also performed to produce uniform pillar surfaces and novel hierarchical pillar surfaces. A uniform nanopillar surface with pillars having diameters of 20-850 nm and a hierarchical pillar surface with thick pillars having diameters ranging from 100 to 860 nm and thin pillars with diameters ranging from 20 to 40 nm were mixed and fabricated. Condensation experiments were performed using the noncoated nanopillar surfaces, and the condensation behaviors on the silicon (Si) surfaces were observed from above using a microscope and from the side using a high-speed camera. On the uniform surface US-3 and the hierarchical surfaces HS-1 and HS-2, droplet jumps were observed frequently in the droplet size range of 20-50 μm. In contrast, as the droplet size increased to 50 μm or more, the number of jumps observed decreased as the droplet size increased. The frequency of droplet jumps on the hierarchical surfaces from the start of condensation to approximately 2 min was higher than that on the uniform surfaces, although the density of droplet formation on the hierarchical surfaces was not relatively large. On the basis of the observation of droplet behavior from the side surface, we identified that the primary jump was due to the coalescence of droplets adhering to the surface and that the subsequent jump was caused by the droplet coalescence when the jump droplets were reattached. The primary jump occurrence rate was high on all pillar surfaces.
Collapse
Affiliation(s)
- Soumei Baba
- National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba-shi, Ibaraki 305-8564, Japan
| | - Kenichiro Sawada
- Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210, Japan
| | - Kohsuke Tanaka
- Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba-shi, Ibaraki 305-8505, Japan
| | - Atsushi Okamoto
- Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba-shi, Ibaraki 305-8505, Japan
| |
Collapse
|
13
|
Wang L, Li J, Zhang B, Feng S, Zhang M, Wu D, Lu Y, Kai JJ, Liu J, Wang Z, Jiang L. Counterintuitive Ballistic and Directional Liquid Transport on a Flexible Droplet Rectifier. RESEARCH 2020; 2020:6472313. [PMID: 32885170 PMCID: PMC7453356 DOI: 10.34133/2020/6472313] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 07/20/2020] [Indexed: 11/06/2022]
Abstract
Achieving the directional and long-range droplet transport on solid surfaces is widely preferred for many practical applications but has proven to be challenging. Particularly, directionality and transport distance of droplets on hydrophobic surfaces are mutually exclusive. Here, we report that drain fly, a ubiquitous insect maintaining nonwetting property even in very high humidity, develops a unique ballistic droplet transport mechanism to meet these demanding challenges. The drain fly serves as a flexible rectifier to allow for a directional and long-range propagation as well as self-removal of a droplet, thus suppressing unwanted liquid flooding. Further investigation reveals that this phenomenon is owing to the synergistic conjunction of multiscale roughness, structural periodicity, and flexibility, which rectifies the random and localized droplet nucleation (nanoscale and microscale) into a directed and global migration (millimeter-scale). The mechanism we have identified opens up a new approach toward the design of artificial rectifiers for broad applications.
Collapse
Affiliation(s)
- Lei Wang
- Beijing Key Lab of Cryo-Biomedical Engineering and Key Lab of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jing Li
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Bo Zhang
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China
| | - Shile Feng
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Mei Zhang
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Dong Wu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Yang Lu
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Ji Jung Kai
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Jing Liu
- Beijing Key Lab of Cryo-Biomedical Engineering and Key Lab of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zuankai Wang
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Lei Jiang
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China
| |
Collapse
|
14
|
Heterogeneous nucleation of argon vapor on the nanostructure surface with molecular dynamics simulation. J Mol Graph Model 2020; 100:107674. [PMID: 32750651 DOI: 10.1016/j.jmgm.2020.107674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 11/21/2022]
Abstract
The study of vapor condensation on surface has important engineering significance. The condensation nucleation process of vapor on substrates with different pillar structures is studied through molecular dynamic simulation. The condensation droplets on the pillar with various heights and solid fractions exhibit Wenzel state, Cassie state and the transformation from Wenzel state to Cassie state. The results show that the condensation efficiencies are correlated with the state of droplet and it is explained from the perspective of heat transfer. For the Wenzel state, the droplet fills the gap of pillar and the form of the heat conduction change with the growth of cluster. In the initial of condensation droplets, the heat conduction is similar with various heights of pillar. As the condensation droplets grow, the efficiency of heat conduction enhances with the increasing of height of pillar. For the Cassie state, the form of heat conduction is perpetual during the condensation process with the thermal resistance of the droplet dominated due to the droplets suspended on the pillar. The efficiency of heat transfer is insensitive to the height of pillar. The form of heat conduction for the transformation state transforms from Wenzel state to Cassie state leading to the reduction of condensation rate. The droplet formed in the Wenzel state has the higher transfer efficiency than the Cassie one.
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
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: 2] [Impact Index Per Article: 0.5] [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.
Collapse
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
| |
Collapse
|
17
|
Chen X, Li Q, Hou K, Li X, Wang Z. Microflower-Decorated Superhydrophobic Copper Surface for Dry Condensation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:16275-16280. [PMID: 31721586 DOI: 10.1021/acs.langmuir.9b02623] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ability to keep surfaces dry is highly desired in many industrial settings, such as condensation, anti-icing, and antifogging. During those applications, phase-change processes are normally involved, and thus the superior superhydrophobic state manifested under ambient conditions is susceptible to collapse under these extreme conditions. Although the design of refined textures offers potential to maintain dry surfaces, the large-scale fabrication of these surfaces is tedious and costly. Herein, we report a facile one-step solution-immersion technique that allows for the attainment of sustained and dry condensation surfaces. Careful optimization of the synthesis procedure and surface morphology, especially the density of microflower structures, the wetting states and departure dynamics of condensate droplets can be mediated, leading to the overall enhanced performances. Our results not only provide important insight for the design of surfaces that promote efficient droplet departure but also promise a large-scale fabrication approach to increase heat transfer in many industrial applications.
Collapse
Affiliation(s)
- Xuemei Chen
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Qiang Li
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Kongyang Hou
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Xiaoyang Li
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Zuankai Wang
- Department of Mechanical Engineering , City University of Hong Kong , Hong Kong 999077 , China
| |
Collapse
|
18
|
Song J, Huang L, Zhao C, Wu S, Liu H, Lu Y, Deng X, Carmalt CJ, Parkin IP, Sun Y. Robust Superhydrophobic Conical Pillars from Syringe Needle Shape to Straight Conical Pillar Shape for Droplet Pancake Bouncing. ACS APPLIED MATERIALS & INTERFACES 2019; 11:45345-45353. [PMID: 31651139 DOI: 10.1021/acsami.9b16509] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Superhydrophobic conical pillars have great industrial application potential in, for example, anti-icing of aircraft wings and protecting high voltage transmission lines from freezing rain because of their droplet pancake bouncing phenomenon, which is recognized to further reduce the liquid-solid contact time. However, there are still no methods that can fabricate robust superhydrophobic conical pillars in large scale. Here, a mold replication technology was proposed to realize the large-scale fabrication of superhydrophobic conical pillars with high mechanical strength. An Al mold with intensive conical holes decorated with micro/nanometer-scale structures was fabricated by nanosecond laser drilling and HCl etching. The conical shape originated from a near Gaussian spatial distribution of the energy and temperature in the radial direction in the laser drilling processes. Robust superhydrophobic conical pillars from syringe needle shape to straight conical pillar shape were easily fabricated through replication from the Al mold without any extra spray of superhydrophobic nanoparticles. It was also found that although all superhydrophobic conical pillars with different shapes could generate the droplet pancake bouncing, the shape had a great influence on the critical bottom space and the critical Weber number (We) to generate pancake bouncing. The pancake bouncing with the shortest contact time of a 68.5% reduction appeared on superhydrophobic straight conical pillars with the shape angle of 180°. Overcoming the difficulties in the large-scale fabrication and robustness of superhydrophobic conical pillars will promote practical applications of the droplet pancake bouncing phenomenon.
Collapse
Affiliation(s)
- Jinlong Song
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education , Dalian University of Technology , Dalian 116024 , P. R. China
| | - Liu Huang
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education , Dalian University of Technology , Dalian 116024 , P. R. China
| | - Changlin Zhao
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education , Dalian University of Technology , Dalian 116024 , P. R. China
| | - Song Wu
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education , Dalian University of Technology , Dalian 116024 , P. R. China
| | - Hong Liu
- Key Laboratory of Theoretical Chemistry of Environment Ministry of Education , South China Normal University , Guangzhou 510006 , P. R. China
| | - Yao Lu
- Department of Chemistry, School of Biological and Chemical Sciences , Queen Mary University of London , London E1 4NS , U.K
| | - Xu Deng
- Institute of Fundamental and Frontier Sciences , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Claire J Carmalt
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , U.K
| | - Ivan P Parkin
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , U.K
| | - Yuwen Sun
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education , Dalian University of Technology , Dalian 116024 , P. R. China
| |
Collapse
|
19
|
Molecular Dynamics Simulation of the Influence of Nanoscale Structure on Water Wetting and Condensation. MICROMACHINES 2019; 10:mi10090587. [PMID: 31480496 PMCID: PMC6780133 DOI: 10.3390/mi10090587] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 02/07/2023]
Abstract
Recent advances in the microfabrication technology have made it possible to control surface properties at micro- and nanoscale levels. Functional surfaces drastically change wettability and condensation processes that are essential for controlling of heat transfer. However, the direct observation of condensation on micro- and nanostructure surfaces is difficult, and further understanding of the effects of the microstructure on the phase change is required. In this research, the contact angle of droplets with a wall surface and the initial condensation process were analyzed using a molecular dynamics simulation to investigate the impact of nanoscale structures and their adhesion force on condensation. The results demonstrated the dependence of the contact angle of the droplets and condensation dynamics on the wall structure and attractive force of the wall surface. Condensed water droplets were adsorbed into the nanostructures and formed a water film in case of a hydrophilic surface.
Collapse
|
20
|
Wang Q, Wang Y, Wang B, Liang Z, Di J, Yu J. Under-liquid dual superlyophobic nanofibrous polymer membranes achieved by coating thin-film composites: a design principle. Chem Sci 2019; 10:6382-6389. [PMID: 31341594 PMCID: PMC6610571 DOI: 10.1039/c9sc01607d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/20/2019] [Indexed: 11/21/2022] Open
Abstract
Under-liquid dual superlyophobic polymer membranes are fabricated by coating thin-film composites, achieving efficient separation of arbitrary oil/water mixtures and emulsions.
Surfaces with under-liquid dual superlyophobicity have garnered tremendous interest because of their promising applications, but their unexplored underlying nature restricts the designed construction of such surfaces. Herein, we coated the thin-film composites with different terminal groups over the electrospun polyacrylonitrile nanofibrous membranes, which afforded the membranes excellent stability in organic solvents, as well as modulated under-liquid wetting behaviors. Among them, the representative under-liquid dual superlyophobic 4-cyan-Ph-terminated membrane could realize highly efficient separation of all types of oil/water mixtures and even emulsions. Moreover, we found that the under-liquid wetting behaviors could be classified in terms of the intrinsic water contact angle (θw). By comparing the total interfacial energy, we proved that the under-liquid dual lyophobic surfaces were thermodynamically metastable. On this basis, we could predict the θw of rough surfaces with the under-liquid dual lyophobicity in a given oil–water–solid system (e.g., 47.3–89.1° in cyclohexane–water–solid system, R = 2). This work provides a design principle for the fabrication of under-liquid dual superlyophobic surfaces, which will open potential applications in diverse fields in terms of such smart surfaces.
Collapse
Affiliation(s)
- Qifei Wang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry , College of Chemistry , Jilin University , Changchun 130012 , P. R. China . ;
| | - Yang Wang
- Department of Mechanical Engineering , City University of Hong Kong , 83rd Tat Chee Avenue , Kowloon , Hong Kong
| | - Baixian Wang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry , College of Chemistry , Jilin University , Changchun 130012 , P. R. China . ;
| | - Zhiqiang Liang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry , College of Chemistry , Jilin University , Changchun 130012 , P. R. China . ;
| | - Jiancheng Di
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry , College of Chemistry , Jilin University , Changchun 130012 , P. R. China . ;
| | - Jihong Yu
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry , College of Chemistry , Jilin University , Changchun 130012 , P. R. China . ; .,International Center of Future Science , Jilin University , Changchun 130012 , P. R. China
| |
Collapse
|
21
|
Li J, Li J, Sun J, Feng S, Wang Z. Biological and Engineered Topological Droplet Rectifiers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806501. [PMID: 30697833 DOI: 10.1002/adma.201806501] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/18/2018] [Indexed: 06/09/2023]
Abstract
The power of the directional and spontaneous transport of liquid droplets is revealed through ubiquitous biological processes and numerous practical applications, where droplets are rectified to achieve preferential functions. Despite extensive progress, the fundamental understanding and the ability to exploit new strategies to rectify droplet transport remain elusive. Here, the latest progress in the fundamental understanding as well as the development of engineered droplet rectifiers that impart superior performance in a wide variety of working conditions, ranging from low temperature, ambient temperature, to high temperature, is discussed. For the first time, a phase diagram is formulated that naturally connects the droplet dynamics, including droplet formation modes, length scales, and phase states, with environmental conditions. Parallel approaches are then taken to discuss the basic physical mechanisms underlying biological droplet rectifiers, and a variety of strategies and manufacturing routes for the development of robust artificial droplet rectifiers. Finally, perspectives on how to create novel man-made rectifiers with functionalities beyond natural counterparts are presented.
Collapse
Affiliation(s)
- Jing Li
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Jiaqian Li
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Jing Sun
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Shile Feng
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Zuankai Wang
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, China
- Shenzhen Research Institute of City University of Hong Kong, Shenzhen, 518057, China
| |
Collapse
|
22
|
Lu J, Ngo CV, Singh SC, Yang J, Xin W, Yu Z, Guo C. Bioinspired Hierarchical Surfaces Fabricated by Femtosecond Laser and Hydrothermal Method for Water Harvesting. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3562-3567. [PMID: 30759979 DOI: 10.1021/acs.langmuir.8b04295] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The world is facing a global issue of water scarcity where two-thirds of the population does not have access to safe drinking water. Water harvesting from the ambient environment has a potential equivalent to ∼10% of the fresh water available on the earth's surface, but its efficiency requires a special control of surface morphology. We report a novel facile physicochemical hybrid method that combines femtosecond laser structuring with hydrothermal treatment to create a surface with a well-arranged hierarchical nanoneedle structures. Polydimethylsiloxane treatment of the thus-produced hierarchical structures nurtured superhydrophobic functionality with a very low water sliding angle (∼3°) and a high water adhesion ability. About 2.2 times higher water-collection efficiency was achieved using hierarchical structures over untreated flat Ti surfaces of the same area under a given experimental condition. The comparison of water-collection behavior with other samples showed that the improved efficiency is due to the structure, and wettability induced superior water attraction and removal ability. Moreover, a uniform water condensation under low humidity (28%) is achieved, which has potential applications in harvesting water from arid environments and in high-precision drop control.
Collapse
Affiliation(s)
- Jinlong Lu
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
| | - Chi-Vinh Ngo
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
| | - Subhash C Singh
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
- The Institute of Optics , University of Rochester , Rochester , New York 14627 , United States
| | - Jianjun Yang
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
| | - Wei Xin
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
| | - Zhi Yu
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
| | - Chunlei Guo
- The Guo China-U.S. Photonics Lab , Changchun Institute of Optics, Fine Mechanics, and Physics , Changchun 130033 , China
- The Institute of Optics , University of Rochester , Rochester , New York 14627 , United States
| |
Collapse
|
23
|
Zhang D, Zhou S, Liu Y, Fan X, Zhang M, Zhai J, Jiang L. Self-Assembled Porphyrin Nanofiber Membrane-Decorated Alumina Channels for Enhanced Photoelectric Response. ACS NANO 2018; 12:11169-11177. [PMID: 30376291 DOI: 10.1021/acsnano.8b05695] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Photoresponsive nanochannel systems whose ionic transportation properties can be controlled by the photoelectric effect, such as for green chlorophyll pigments in plants, are attracting widespread attention. Herein, we prepared photoresponsive heterogeneous nanochannels by decorating self-assembled tetra(4-sulfonatophenyl)porphyrin (TPPS) nanofiber membranes on a membrane of hourglass-shaped alumina (Al2O3) nanochannels using the diffusion-limited patterning (DLP) method. The close arrangement of large-area nanofibers promoted the photoresponse sensitivity of the heterogeneous nanochannels, which showed the highest ionic transportation current. With illumination comparable to sunlight in intensity, the photoresponsive ionic current was approximately 9.7 μA, demonstrating photoswitching, which could be used to regulate the reversible transformation of ionic currents. Meanwhile, the cooperative effect of the TPPS nanofibers assembled at the entrance to the nanochannels and the TPPS molecules inside the nanochannels allowed the heterogeneous nanochannels to exhibit a good rectifying performance.
Collapse
Affiliation(s)
- Dan Zhang
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry , Beihang University , Beijing 100083 , People's Republic of China
| | - Shuqi Zhou
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry , Beihang University , Beijing 100083 , People's Republic of China
| | - You Liu
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry , Beihang University , Beijing 100083 , People's Republic of China
| | - Xia Fan
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry , Beihang University , Beijing 100083 , People's Republic of China
| | - Mingliang Zhang
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors , Chinese Academy of Sciences , Beijing 100083 , People's Republic of China
- College of Materials Science and Optoelectronic Technology , University of Chinese Academy of Sciences , Beijing 101408 , People's Republic of China
| | - Jin Zhai
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry , Beihang University , Beijing 100083 , People's Republic of China
| | - Lei Jiang
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry , Beihang University , Beijing 100083 , People's Republic of China
| |
Collapse
|
24
|
Wang J, Gao W, Zhang H, Zou M, Chen Y, Zhao Y. Programmable wettability on photocontrolled graphene film. SCIENCE ADVANCES 2018; 4:eaat7392. [PMID: 30225367 PMCID: PMC6140404 DOI: 10.1126/sciadv.aat7392] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/07/2018] [Indexed: 05/17/2023]
Abstract
Surface materials with specific wettability play important roles in a wide variety of areas from science to industry. We present a novel paraffin-infused porous graphene film (PIPGF) with programmable wettability. Because of graphene's photothermal property, the paraffin in the PIPGF was in transition between liquid and solid in response to near-infrared (NIR) light irradiation. Thus, we imparted the film with a dynamic and reversible transition between a slippery and a rough surface as the remotely tunable wettability. In addition, with the integration of NIR masks, the paraffin could melt at corresponding patterns on the PIPGF, which formed special flow pathways for the slipping droplets. Therefore, the PIPGF could provide programmable wettability pathways for the spatiotemporal droplet manipulation by flexibly changing the NIR masks. We demonstrated these programmable wettability pathways to not only simplify liquid handling in the microplates and droplet microarrays technology but also to provide distinctly microfluidic microreactors for different purposes, such as practical blood grouping diagnosis. These features indicated that the photocontrollable PIPGF would be amenable to a variety of applications, such as microfluidic systems, laboratory-on-a-chip settings, and droplet manipulations.
Collapse
Affiliation(s)
- Jie Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Wei Gao
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Han Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Minhan Zou
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Yongping Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
- Corresponding author. (Y.Z.); (Y.C.)
| | - Yuanjin Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
- Corresponding author. (Y.Z.); (Y.C.)
| |
Collapse
|
25
|
Li H, Aili A, Alhosani MH, Ge Q, Zhang T. Directional Passive Transport of Microdroplets in Oil-Infused Diverging Channels for Effective Condensate Removal. ACS APPLIED MATERIALS & INTERFACES 2018; 10:20910-20919. [PMID: 29792417 DOI: 10.1021/acsami.8b00922] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Condensation widely exists in nature and industry, and its performance heavily relies on the efficiency of condensate removal. Recent advances in micro-/nanoscale surface engineering enable condensing droplet removal from solid surfaces without extra energy cost, but it is still challenging to achieve passive transport of microdroplets over long distances along horizontal surfaces. The mobility of these condensate droplets can be enhanced by lubricant oil infusion on flat surfaces and frequent coalescence, which lead to fast growth but random motion of droplets. In this work, we propose a novel design of diverging microchannels with oil-infused surfaces to achieve controllable, long-distance, and directional transport of condensing droplets on horizontal surfaces. This idea is experimentally demonstrated with diverging copper and silicon microchannels with nanoengineered surfaces. Along these hierarchical surface structures, microdroplets condense on the top channel wall and submerge into microchannels owing to the capillary pressure gradient in infusing oil. Confined by the microchannel walls, the submerged droplets deform and maintain the back-front curvature difference, which enables the motion of droplets along the channel diverging direction. Subsequent droplet coalescences inside the channel further enhance this directional transport. Moreover, fast-moving deformed droplets transfer their momentum to downstream spherical droplets through the infusing oil. As a result, simultaneous passive transport of multiple droplets (20-400 μm) is achieved over long distances (beyond 7 mm). On these oil-infused surfaces, satellite microdroplets can further nucleate and grow on an oil-cloaked droplet, demonstrating an enlarged surface area for condensation. Our findings on passive condensate removal offer great opportunities in condensation enhancement, self-cleaning, and other applications requiring directional droplet transport along horizontal surfaces.
Collapse
Affiliation(s)
- Hongxia Li
- Department of Mechanical and Materials Engineering , Masdar Institute, Khalifa University of Science and Technology , P.O. Box 54224, Abu Dhabi , UAE
| | - Ablimit Aili
- Department of Mechanical and Materials Engineering , Masdar Institute, Khalifa University of Science and Technology , P.O. Box 54224, Abu Dhabi , UAE
| | - Mohamed H Alhosani
- Department of Mechanical and Materials Engineering , Masdar Institute, Khalifa University of Science and Technology , P.O. Box 54224, Abu Dhabi , UAE
| | - Qiaoyu Ge
- Department of Mechanical and Materials Engineering , Masdar Institute, Khalifa University of Science and Technology , P.O. Box 54224, Abu Dhabi , UAE
| | - TieJun Zhang
- Department of Mechanical and Materials Engineering , Masdar Institute, Khalifa University of Science and Technology , P.O. Box 54224, Abu Dhabi , UAE
| |
Collapse
|
26
|
Han Z, Feng X, Guo Z, Niu S, Ren L. Flourishing Bioinspired Antifogging Materials with Superwettability: Progresses and Challenges. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1704652. [PMID: 29441617 DOI: 10.1002/adma.201704652] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/05/2017] [Indexed: 05/20/2023]
Abstract
Antifogging (AF) structure materials found in nature have great potential for enabling novel and emerging products and technologies to facilitate the daily life of human societies, attracting enormous research interests owing to their potential applications in display devices, traffics, agricultural greenhouse, food packaging, solar products, and other fields. The outstanding performance of biological AF surfaces encourages the rapid development and wide application of new AF materials. In fact, AF properties are inextricably associated with their surface superwettability. Generally, the superwettability of AF materials depends on a combination of their surface geometrical structures and surface chemical compositions. To explore their general design principles, recent progresses in the investigation of bioinspired AF materials are summarized herein. Recent developments of the mechanism, fabrication, and applications of bioinspired AF materials with superwettability are also a focus. This includes information on constructing superwetting AF materials based on designing the topographical structure and regulating the surface chemical composition. Finally, the remaining challenges and promising breakthroughs in this field are also briefly discussed.
Collapse
Affiliation(s)
- Zhiwu Han
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, 130022, Jilin, P. R. China
| | - Xiaoming Feng
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, 130022, Jilin, P. R. China
| | - Zhiguang Guo
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, 130022, Jilin, P. R. China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Shichao Niu
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, 130022, Jilin, P. R. China
| | - Luquan Ren
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, 130022, Jilin, P. R. China
| |
Collapse
|
27
|
Su X, Li H, Lai X, Zhang L, Liao X, Wang J, Chen Z, He J, Zeng X. Dual-Functional Superhydrophobic Textiles with Asymmetric Roll-Down/Pinned States for Water Droplet Transportation and Oil-Water Separation. ACS APPLIED MATERIALS & INTERFACES 2018; 10:4213-4221. [PMID: 29323869 DOI: 10.1021/acsami.7b15909] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Superhydrophobic surfaces with tunable adhesion from lotus-leaf to rose-petal states have generated much attention for their potential applications in self-cleaning, anti-icing, oil-water separation, microdroplet transportation, and microfluidic devices. Herein we report a facile magnetic-field-manipulation strategy to fabricate dual-functional superhydrophobic textiles with asymmetric roll-down/pinned states on the two surfaces of the textile simultaneously. Upon exposure to a static magnetic field, fluoroalkylsilane-modified iron oxide (F-Fe3O4) nanoparticles in polydimethylsiloxane (PDMS) moved along the magnetic field to construct discrepant hierarchical structures and roughnesses on the two sides of the textile. The positive surface (closer to the magnet, or P-surface) showed a water contact angle up to 165°, and the opposite surface (or O-surface) had a water contact angle of 152.5°. The P-surface where water droplets easily slid off with a sliding angle of 7.5° appeared in the "roll-down" state as Cassie mode, while the O-surface was in the "pinned" state as Wenzel mode, where water droplets firmly adhered even at vertical (90°) and inverted (180°) angles. The surface morphology and wetting mode were adjustable by varying the ratios of F-Fe3O4 nanoparticles and PDMS. By taking advantage of the asymmetric adhesion behaviors, the as-fabricated superhydrophobic textile was successfully applied in no-loss microdroplet transportation and oil-water separation. Our method is simple and cost-effective. The fabricated textile has the characteristics of superhydrophobicity, magnetic responsiveness, excellent chemical stability, adjustable surface morphology, and controllable adhesion. Our findings conceivably stand out as a new tool to fabricate functional superhydrophobic materials with asymmetric surface properties for various potential applications.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Jie He
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269, United States
| | | |
Collapse
|
28
|
Han Z, Feng X, Jiao Z, Wang Z, Zhang J, Zhao J, Niu S, Ren L. Bio-inspired antifogging PDMS coupled micro-pillared superhydrophobic arrays and SiO2 coatings. RSC Adv 2018; 8:26497-26505. [PMID: 35541092 PMCID: PMC9083089 DOI: 10.1039/c8ra04699a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/05/2018] [Indexed: 11/21/2022] Open
Abstract
Inspired by nature, a bio-inspired antifogging PDMS is designed and fabricated successfully using UV lithography and a template method. It achieves an excellent superhydrophobic antifogging property, which benefits from a coupling effect.
Collapse
Affiliation(s)
- Zhiwu Han
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Xiaoming Feng
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Zhibin Jiao
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Ze Wang
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Junqiu Zhang
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Jie Zhao
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Shichao Niu
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| | - Luquan Ren
- Key Laboratory of Bionic Engineering
- Ministry of Education
- Jilin University
- Changchun 130022
- China
| |
Collapse
|
29
|
Wen R, Xu S, Zhao D, Lee YC, Ma X, Yang R. Hierarchical Superhydrophobic Surfaces with Micropatterned Nanowire Arrays for High-Efficiency Jumping Droplet Condensation. ACS APPLIED MATERIALS & INTERFACES 2017; 9:44911-44921. [PMID: 29214806 DOI: 10.1021/acsami.7b14960] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Self-propelled droplet jumping on nanostructured superhydrophobic surfaces is of interest for a variety of industrial applications including self-cleaning, water harvesting, power generation, and thermal management systems. However, the uncontrolled nucleation-induced Wenzel state of condensed droplets at large surface subcooling (high heat flux) leads to the formation of unwanted large pinned droplets, which results in the flooding phenomenon and greatly degrades the heat transfer performance. In this work, we present a novel strategy to manipulate droplet behaviors during the process from the droplet nucleation to growth and departure through a combination of spatially controlling initial nucleation for mobile droplets by closely spaced nanowires and promoting the spontaneous outward movement of droplets for rapid removal using micropatterned nanowire arrays. Through the optical visualization experiments and heat transfer tests, we demonstrate greatly improved condensation heat transfer characteristics on the hierarchical superhydrophobic surface including the higher density of microdroplets, smaller droplet departure radius, 133% wider range of surface subcooling for droplet jumping, and 37% enhancement in critical heat flux for jumping droplet condensation, compared to the-state-of-art jumping droplet condensation on nanostructured superhydrophobic surfaces. The excellent water repellency of such hierarchical superhydrophobic surfaces can be promising for many potential applications, such as anti-icing, antifogging, water desalination, and phase-change heat transfer.
Collapse
Affiliation(s)
| | | | | | | | - Xuehu Ma
- Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, P. R. China
| | - Ronggui Yang
- Buildings and Thermal Systems Center, National Renewable Energy Laboratory , Golden, Colorado 80401, United States
| |
Collapse
|
30
|
Gong X, Gao X, Jiang L. Recent Progress in Bionic Condensate Microdrop Self-Propelling Surfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703002. [PMID: 28845888 DOI: 10.1002/adma.201703002] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/01/2017] [Indexed: 06/07/2023]
Abstract
Bionic condensate microdrop self-propelling (CMDSP) surfaces are attracting increased attention as novel, low-adhesivity superhydrophobic surfaces due to their value in fundamental research and technological innovation, e.g., for enhancing heat transfer, energy-effective antifreezing, and electrostatic energy harvesting. Here, the focus is on recent progress in bionic CMDSP surfaces. Metal-based CMDSP surfaces, which are the most promising in their respective fields, are highlighted for use in future applications. The selected topics are divided into four sections: biological prototypes, mechanism and construction rules, fabrication, and applications of metal-based CMDSP surfaces. Finally, the challenges and future development trends in bionic CMDSP surfaces are envisioned, especially the utilization of potential bionic inspiration in the design of more advanced CMDSP surfaces.
Collapse
Affiliation(s)
- Xiaojing Gong
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
| | - Xuefeng Gao
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
| | - Lei Jiang
- Key Laboratory of Bio-inspired Smart Interface Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- School of Future Technologies, University of Chinese Academy of Sciences, Beijing, 101407, China
- School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, 100191, P. R. China
| |
Collapse
|
31
|
Gao S, Liao Q, Liu W, Liu Z. Effects of Solid Fraction on Droplet Wetting and Vapor Condensation: A Molecular Dynamic Simulation Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12379-12388. [PMID: 28980811 DOI: 10.1021/acs.langmuir.7b03193] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recently, numerous studies focused on the wetting process of droplets on various surfaces at a microscale level. However, there are a limited number of studies about the mechanism of condensation on patterned surfaces. The present study performed the dynamic wetting behavior of water droplets and condensation process of water molecules on substrates with different pillar structure parameters, through molecular dynamic simulation. The dynamic wetting results indicated that droplets exhibit Cassie state, PW state, and Wenzel state successively on textured surfaces with decreasing solid fraction. The droplets possess a higher static contact angle and a smaller spreading exponent on textured surfaces than those on smooth surfaces. The condensation processes, including the formation, growth, and coalescence of a nanodroplet, are simulated and quantitatively recorded, which are difficult to be observed by experiments. In addition, a wetting transition and a dewetting transition were observed and analyzed in condensation on textured surfaces. Combining these simulation results with previous theoretical and experimental studies will guide us to understand the hypostasis and mechanism of the condensation more clearly.
Collapse
Affiliation(s)
- Shan Gao
- School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| | - Quanwen Liao
- School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| | - Wei Liu
- School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| | - Zhichun Liu
- School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| |
Collapse
|
32
|
Zhang P, Maeda Y, Lv F, Takata Y, Orejon D. Enhanced Coalescence-Induced Droplet-Jumping on Nanostructured Superhydrophobic Surfaces in the Absence of Microstructures. ACS APPLIED MATERIALS & INTERFACES 2017; 9:35391-35403. [PMID: 28925681 DOI: 10.1021/acsami.7b09681] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Superhydrophobic surfaces are receiving increasing attention due to the enhanced condensation heat transfer, self-cleaning, and anti-icing properties by easing droplet self-removal. Despite the extensive research carried out on this topic, the presence or absence of microstructures on droplet adhesion during condensation has not been fully addressed yet. In this work we, therefore, study the condensation behavior on engineered superhydrophobic copper oxide surfaces with different structural finishes. More specifically, we investigate the coalescence-induced droplet-jumping performance on superhydrophobic surfaces with structures varying from the micro- to the nanoscale. The different structural roughness is possible due to the specific etching parameters adopted during the facile low-cost dual-scale fabrication process. A custom-built optical microscopy setup inside a temperature and relative humidity controlled environmental chamber was used for the experimental observations. By varying the structural roughness, from the micro- to the nanoscale, important differences on the number of droplets involved in the jumps, on the frequency of the jumps, and on the size distribution of the jumping droplets were found. In the absence of microstructures, we report an enhancement of the droplet-jumping performance of small droplets with sizes in the same order of magnitude as the microstructures. Microstructures induce further droplet adhesion, act as a structural barrier for the coalescence between droplets growing on the same microstructure, and cause the droplet angular deviation from the main surface normal. As a consequence, upon coalescence, there is a decrease in the net momentum in the out-of-plane direction, and the jump does not ensue. We demonstrate that the absence of microstructures has therefore a positive impact on the coalescence-induced droplet-jumping of micrometer droplets for antifogging, anti-icing, and condensation heat transfer applications.
Collapse
Affiliation(s)
- Peng Zhang
- Institute of Refrigeration and Cryogenics, MOE Key Laboratory for Power Machinery and Engineering, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Yota Maeda
- Department of Mechanical Engineering, Thermofluid Physics Laboratory, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Fengyong Lv
- Institute of Refrigeration and Cryogenics, MOE Key Laboratory for Power Machinery and Engineering, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Yasuyuki Takata
- Department of Mechanical Engineering, Thermofluid Physics Laboratory, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Daniel Orejon
- Department of Mechanical Engineering, Thermofluid Physics Laboratory, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| |
Collapse
|
33
|
Wang K, Liang Q, Jiang R, Zheng Y, Lan Z, Ma X. Numerical Simulation of Coalescence-Induced Jumping of Multidroplets on Superhydrophobic Surfaces: Initial Droplet Arrangement Effect. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:6258-6268. [PMID: 28562053 DOI: 10.1021/acs.langmuir.7b00901] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The coalescence-induced droplet jumping on superhydrophobic surfaces (SHSs) has attracted considerable attention over the past several years. Most of the studies on droplet jumping mainly focus on two-droplet coalescence events whereas the coalescence of three or more droplets is actually more frequent and still remains poorly understood. In this work, a 3D lattice Boltzmann simulation is carried out to investigate the effect of initial droplet arrangements on the coalescence-induced jumping of three equally sized droplets. Depending on the initial position of droplets on the surface, the droplet coalescence behaviors can be generally classified into two types: one is that all droplets coalesce together instantaneously (concentrated configuration), and the other is that the initial coalesced droplet sweeps up the third droplet in its moving path (spaced configuration). The critical Ohnesorge number, Oh, for the transition of inertial-capillary-dominated coalescence to inertially limited-viscous coalescence is found to be 0.10 for droplet coalescence on SHSs with a contact angle of 160°. The jumping droplet velocity for concentrated multidroplet coalescence at Oh ⩽ 0.10 still follows the inertial-capillary scaling with an increased prefactor, which indicates a viable jumping droplet velocity enhancement scheme. However, the droplet jumping velocity is drastically reduced for the spaced configuration compared to that for the aforementioned concentrated configuration. Because Oh exceeds 0.10, the effects of initial droplet arrangements on multidroplet jumping become weaker as viscosity plays a key role in the merging process. This work will provide effective guidelines for the design of functional SHSs with enhanced droplet jumping for a wide range of industrial applications.
Collapse
Affiliation(s)
- Kai Wang
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Qianqing Liang
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Rui Jiang
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Yi Zheng
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Zhong Lan
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Xuehu Ma
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| |
Collapse
|