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Li Z, Zhang JH, Li J, Wang S, Zhang L, He CY, Lin P, Melhi S, Yang T, Yamauchi Y, Xu X. Dynamical Janus-Like Behavior Excited by Passive Cold-Heat Modulation in the Earth-Sun/Universe System: Opportunities and Challenges. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309397. [PMID: 38644343 DOI: 10.1002/smll.202309397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/02/2024] [Indexed: 04/23/2024]
Abstract
The utilization of solar-thermal energy and universal cold energy has led to many innovative designs that achieve effective temperature regulation in different application scenarios. Numerous studies on passive solar heating and radiation cooling often operate independently (or actively control the conversion) and lack a cohesive framework for deep connections. This work provides a concise overview of the recent breakthroughs in solar heating and radiation cooling by employing a mechanism material in the application model. Furthermore, the utilization of dynamic Janus-like behavior serves as a novel nexus to elucidate the relationship between solar heating and radiation cooling, allowing for the analysis of dynamic conversion strategies across various applications. Additionally, special discussions are provided to address specific requirements in diverse applications, such as optimizing light transmission for clothing or window glass. Finally, the challenges and opportunities associated with the development of solar heating and radiation cooling applications are underscored, which hold immense potential for substantial carbon emission reduction and environmental preservation. This work aims to ignite interest and lay a solid foundation for researchers to conduct in-depth studies on effective and self-adaptive regulation of cooling and heating.
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Affiliation(s)
- Zhengtong Li
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, China
| | - Jia-Han Zhang
- School of Electronic Information Engineering, Inner Mongolia University, Hohhot, 010021, China
- Collaborative Innovation Center of Advanced Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Jiaoyang Li
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, China
| | - Song Wang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, China
| | - Lvfei Zhang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, China
| | - Cheng-Yu He
- Laboratory of Clean Energy Chemistry and Materials, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Peng Lin
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, China
| | - Saad Melhi
- Department of Chemistry, College of Science, University of Bisha, Bisha, 61922, Saudi Arabia
| | - Tao Yang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, China
| | - Yusuke Yamauchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea
- Department of Materials Process Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
| | - Xingtao Xu
- Department of Materials Process Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, 316022, China
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2
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Zhang Y, Wu C, Gu H, Song Y, Zhao R, Zhang D, Xie Z, Liu Y, Cheng Z. An Active Strategy Based on Different Droplet Removal Modes on Polydimethylsiloxane Magnetic Microstructures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2400466. [PMID: 38676346 DOI: 10.1002/smll.202400466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/17/2024] [Indexed: 04/28/2024]
Abstract
The efficient removal of droplets on solid surfaces holds significant importance in the field of fog collection, condensation heat transfer, and so on. However, on current typical surfaces, droplets are characterized by a passive and single removal mode, contingent on the traction force (e.g., capillary force, Laplace pressure, etc.) generated by the surface's physics and chemistry design, posing challenges for enhancing the efficiency of droplet removal. In this paper, an effective active strategy based on different removal modes is demonstrated on magnetic responsive polydimethylsiloxane (PDMS) superhydrophobic microplates (RM-MPSM). By regulating the parameters of microplates and droplet volume, different effective departure modes (top jumping and side departure) can be induced to facilitate the removal of droplets. Moreover, the removal volume of droplets through the side departure mode exhibits a significant reduction compared to that observed in the top jumping mode. The exceptional removal ability of RM-MPSM demonstrates adaptability to diverse functional applications: efficient fog collection, removal of condensation droplets and micro-particles. The efficient modes of droplet removal demonstrated in this work hold significant implications for broadening its application in many fields, such as droplet collection, heat transfer, and anti-icing.
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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, P. R. China
| | - Chao Wu
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Haoyu Gu
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Yingbin Song
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Ruoxi Zhao
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Dongjie Zhang
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Zhimin Xie
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, P. R. China
| | - Yuyan Liu
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Zhongjun Cheng
- State Key Laboratory of Urban Water Resource & Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
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Ma C, Zhou C. Scaling Laws for the Influence of Gravity and Its Gradient on Dropwise Condensation: A Simulation Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:14118-14129. [PMID: 38913660 DOI: 10.1021/acs.langmuir.4c01572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Gravity is essential for the shedding of condensed droplets on hydrophobic surfaces, whose influences on condensation parameters under unconventional gravity conditions remain unclear and are hard to probe through experiments. A simulation framework is designed here to investigate such phase-change processes. We find clear scaling laws between heat flux Q, residual volume V, gravitational acceleration g, and nucleation density N0 with Q ∼ g1/6N01/3 and V ∼ g-1/2N00. We also identify a critical gravitational acceleration determined by nucleation density, above which a counterintuitive trend emerges: the heat flux decreases with increasing gravitational acceleration. This deviation is attributed to the sharp decrease in heat flux contributed by droplets larger than the effective radius. In addition, for zero-gravity scenarios, a centrifugal strategy is proposed to simulate Earth's gravity by introducing artificial gravity with a spatial gradient. We reveal that the gradients have a significant influence on the residual volume but a minor one on the heat flux. The conclusions are informative for the estimation and design of condensation heat transfer systems for future space applications.
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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
| | - Chucheng Zhou
- Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
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4
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Zhang J, Li B, Zhou Z, Zhang J. Durable Superhydrophobic Surfaces with Self-Generated Wenzel Sites for Efficient Fog Collection. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2312112. [PMID: 38409650 DOI: 10.1002/smll.202312112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/05/2024] [Indexed: 02/28/2024]
Abstract
Harvesting freshwater from fog is one of the possible solutions to the global water scarcity crisis. Surfaces with both hydrophobic and hydrophilic regions are extensively employed for this purpose. Nevertheless, the longevity of these surfaces is still constrained by their delicate surface structures. The hydrophilic zones may become damaged or contaminated after repeated use, thereby compromising their effectiveness in fog collection. The preparation of generally applicable durable superhydrophobic coatings with self-generated Wenzel sites is reported here for long-term efficient and stable fog collection. The coatings are prepared by depositing the poly(tannic acid) coating as the primer layer on various substrates, self-assembly of trichlorovinylsilane into staggered silicone nanofilaments, and then thiol-ene click reaction with 1H,1H,2H,2H-perfluorodecanethiol. The coatings demonstrate remarkable static superhydrophobicity, robust impalement resistance, and stable self-generated Wenzel sites for water droplets. Therefore, the fog collection rate (FCR) of the coatings reaches 2.13 g cm-2 h-1 during 192 h continuous fog collection, which is triple that of bare substrate and outperforms most previous studies. Moreover, the systematic experiments and models have revealed that the key factors for achieving high FCR on superhydrophobic coatings are forming condensed droplets ≈1 mm in critical radius and a Wenzel site proportion of 0.3-0.4.
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Affiliation(s)
- Jiaren Zhang
- Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Bucheng Li
- Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Zhengqiang Zhou
- Gansu Water Investment Co., Ltd., Lanzhou, 730000, P. R. China
| | - Junping Zhang
- Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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5
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Zhao P, Gong S, Zhang C, Chen S, Cheng P. Roles of Wettability and Wickability on Enhanced Hydrogen Evolution Reactions. ACS APPLIED MATERIALS & INTERFACES 2024; 16:27898-27907. [PMID: 38749009 DOI: 10.1021/acsami.4c02428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Bubble dynamics significantly impact mass transfer and energy conversion in electrochemical gas evolution reactions. Micro-/nanostructured surfaces with extreme wettability have been employed as gas-evolving electrodes to promote bubble departure and decrease the bubble-induced overpotential. However, effects of the electrodes' wickability on the electrochemical reaction performances remain elusive. In this work, hydrogen evolution reaction (HER) performances are experimentally investigated using micropillar array electrodes with varying interpillar spacings, and effects of the electrodes' wettability, wickability as well as bubble adhesion are discussed. A deep learning-based object detection model was used to obtain bubble counts and bubble departure size distributions. We show that microstructures on the electrode have little effect on the total bubble counts and bubble size distribution characteristics at low current densities. At high current densities, however, micropillar array electrodes have much higher total bubble counts and smaller bubble departure sizes compared with the flat electrode. We also demonstrate that surface wettability is a critical factor influencing HER performances under low current densities, where bubbles exist in an isolated regime. Under high current densities, where bubbles are in an interacting regime, the wickability of the micropillar array electrodes emerges as a determining factor. This work elucidates the roles of surface wettability and wickability on enhancing electrochemical performances, providing guidelines for the optimal design of micro-/nanostructured electrodes in various gas evolution reactions.
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Affiliation(s)
- Panpan Zhao
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shuai Gong
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chaoyang Zhang
- Paris Elite Institute of Technology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Siliang Chen
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ping Cheng
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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6
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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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7
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Chen L, Shi D, Kang X, Ma C, Zheng Q. Deep Learning Enabled Comprehensive Evaluation of Jumping-Droplet Condensation and Frosting. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38693061 DOI: 10.1021/acsami.4c00976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Superhydrophobicity-enabled jumping-droplet condensation and frosting have great potential in various engineering applications, ranging from heat transfer processes to antifog/frost techniques. However, monitoring such droplets is challenging due to the high frequency of droplet behaviors, cross-scale distribution of droplet sizes, and diversity of surface morphologies. Leveraging deep learning, we develop a semisupervised framework that monitors the optical observable process of condensation and frosting. This system is adept at identifying transient droplet distributions and dynamic activities, such as droplet coalescence, jumping, and frosting, on a variety of superhydrophobic surfaces. Utilizing this transient and dynamic information, various physical properties, such as heat flux, jumping characteristics, and frosting rate, can be further quantified, conveying the heat transfer and antifrost performances of each surface perceptually and comprehensively. Furthermore, this framework relies on only a small amount of annotated data and can efficiently adapt to new condensation conditions with varying surface morphologies and illumination techniques. This adaptability is beneficial for optimizing surface designs to enhance condensation heat transfer and antifrosting performance.
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Affiliation(s)
- Li Chen
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Diwei Shi
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Xinyue Kang
- School of Civil Aviation, Northwestern Polytechnical University, Xi'an 710072, China
| | - Chen Ma
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Quanshui Zheng
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
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8
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Bai G, Zhang H, Gao D, Fei H, Guo C, Ren M, Liu Y. Controlled condensation by liquid contact-induced adaptations of molecular conformations in self-assembled monolayers. Nat Commun 2024; 15:3132. [PMID: 38605051 PMCID: PMC11009314 DOI: 10.1038/s41467-024-47507-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: 12/12/2023] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
Surface condensation control strategies are crucial but commonly require relatively tedious, time-consuming, and expensive techniques for surface-chemical and topographical engineering. Here we report a strategy to alter surface condensation behavior without resorting to any molecule-type or topographical transmutations. After ultrafast contact of liquids with and removal from surfaces, the condensation rate and density of water droplets on the surfaces decrease, the extent of which is positively correlated with the polarity of the liquid and the duration of contact. The liquid contact-induced condensation rate/density decrease (LCICD) can be attributed to the decrease of nucleation site density resulted from the liquid contact-induced adaption of surface molecular conformation. Based on this, we find that LCICD is applicable to various surfaces, on condition that there are flexible segments capable of shielding at least part of nucleation sites through changing the conformation under liquid contact induction. Leveraging the LCICD effect, we achieve erasable information storage on diverse substrates. Furthermore, our strategy holds promise for controlling condensation of other substances since LCICD is not specific to the water condensation process.
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Affiliation(s)
- Guoying Bai
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China.
| | - Haiyan Zhang
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China
| | - Dong Gao
- Key Laboratory of Hebei Province for Molecular Biophysics, Institute of Biophysics, School of Health Science & Biomedical Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China
| | - Houguo Fei
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei, 430072, P. R. China
| | - Cunlan Guo
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei, 430072, P. R. China
| | - Mingxia Ren
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China
| | - Yufeng Liu
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China
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Zhou W, Feng X, Wang Z, Zhu D, Chu J, Zhu X, Hu Y, Tian G. Superhydrophobic Surfaces with Excellent Ice Prevention and Drag Reduction Properties Inspired by Iridaceae Leaf. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:7192-7204. [PMID: 38503714 DOI: 10.1021/acs.langmuir.4c00333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
The anti-icing and drag-reduction properties of diverse microstructured surfaces have undergone extensive study over the past decade. Nonetheless, tough environments enforce stringent demands on the composite characteristics of superhydrophobic surfaces (SHS). In this study, fresh composite structures were fabricated on a metal substrate by nanosecond laser machining technology, drawing inspiration from the hardy plant Iridaceae. The prepared sample surface mainly consists of a periodic microrhombus array and irregular nanosheets. To comprehensively investigate the effect of its special structure on surface properties, three surfaces with different sizes of rhombic structures were used for comparative analysis, and the results show that the SH-S2 sample is optimal. This can significantly delay the freezing time by an impressive 1404 s at -10 °C while revealing the sample surface anti-icing strategy. In addition, the rheological experiments determined over 300 μm of slip length for the SH-S2 sample, and the drag reduction rate of the surface reaches nearly 40%, which is well aligned with the results of the delayed icing experiments. Finally, the mechanical durability of the SH-S2 surface was investigated through scratch damage, sandpaper abrasion, reparability trials, and icing and melting cycle tests. This research presents a new approach and methodology for the application of SHS on polar ship surfaces.
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Affiliation(s)
- Wen Zhou
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Xiaoming Feng
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Zhizhong Wang
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Dongpo Zhu
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Jiahui Chu
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Xiaohui Zhu
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Yuxue Hu
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Guizhong Tian
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
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10
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Tang Z, Xu B, Man X, Liu H. Bioinspired Superhydrophobic Fibrous Materials. SMALL METHODS 2024; 8:e2300270. [PMID: 37312429 DOI: 10.1002/smtd.202300270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/27/2023] [Indexed: 06/15/2023]
Abstract
Natural fibers with robust water repellency play an important role in adapting organisms to various environments, which has inspired the development of artificial superhydrophobic fibrous materials with applications in self-cleaning, antifogging, water harvesting, heat exchanging, catalytic reactions, and microrobots. However, these highly textured surfaces (micro/nanotextured) suffer from frequent liquid penetration in high humidity and abrasion-induced destruction of the local environment. Herein, bioinspired superhydrophobic fibrous materials are reviewed from the perspective of the dimension scale of fibers. First, the fibrous dimension characteristics of several representative natural superhydrophobic fibrous systems are summarized, along with the mechanisms involved. Then, artificial superhydrophobic fibers are summarized, along with their various applications. Nanometer-scale fibers enable superhydrophobicity by minimizing the liquid-solid contact area. Micrometer-scale fibers are advantageous for enhancing the mechanical stability of superhydrophobicity. Micrometer-scale conical fibrous structures endow a Laplace force with a particular magnitude for self-removing condensed tiny dewdrops in highly humid air and stably trapping large air pockets underwater. Furthermore, several representative surface modification strategies for constructing superhydrophobic fibers are presented. In addition, several conventional applications of superhydrophobic systems are presented. It is anticipated that the review will inspire the design and fabrication of superhydrophobic fibrous systems.
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Affiliation(s)
- Zhongxue Tang
- School of Physics, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
| | - Bojie Xu
- Research Institute for Frontier Science, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
| | - Xingkun Man
- School of Physics, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
| | - Huan Liu
- Research Institute for Frontier Science, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
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11
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Wang DQ, Wang ZJ, Wang SY, Yang YR, Zheng SF, Lee DJ, Wang XD. Coalescence-Induced Jumping of Nanodroplets in a Perpendicular Electric Field: A Molecular Dynamics Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 38298055 DOI: 10.1021/acs.langmuir.3c03758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Coalescence-induced jumping has promised a substantial reduction in the droplet detachment size and consequently shows great potential for heat-transfer enhancement in dropwise condensation. In this work, using molecular dynamics simulations, the evolution dynamics of the liquid bridge and the jumping velocity during coalescence-induced nanodroplet jumping under a perpendicular electric field are studied for the first time to further promote jumping. It is found that using a constant electric field, the jumping performance at the small intensity is weakened owing to the continuously decreased interfacial tension. There is a critical intensity above which the electric field can considerably enhance the stretching effect with a stronger liquid-bridge impact and, hence, improve the jumping performance. For canceling the inhibition effect of the interfacial tension under the condition of the weak electric field, a square-pulsed electric field with a paused electrical effect at the expansion stage of the liquid bridge is proposed and presents an efficient nanodroplet jumping even using the weak electric field.
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Affiliation(s)
- Dan-Qi Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Zi-Jie Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Shao-Yu Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Yan-Ru Yang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Shao-Fei Zheng
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tong 999077, Hong Kong
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 32003, Taiwan
| | - Xiao-Dong Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
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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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13
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Liu Y, Peng X, Zhu L, Jiang R, Liu J, Chen C. Liquid-Assisted Bionic Conical Needle for In-Air and In-Oil-Water Droplet Ultrafast Unidirectional Transportation and Efficient Fog Harvesting. ACS APPLIED MATERIALS & INTERFACES 2023; 15:59920-59930. [PMID: 38100412 DOI: 10.1021/acsami.3c14713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Learning from nature, many bionic materials and surfaces have been developed for the directional transportation of water and fog collection. However, current research mainly focuses on the self-transportation behavior of droplets in air-phase environments, rarely concerning underoil environments. Herein, in this work, a liquid-assisted bionic copper needle was fabricated for the rapid self-transportation of water droplets in air and oil environments. The water droplet can be spontaneously transported on the as-prepared bionic copper needle from the tip to the base. More importantly, the water-prewetted bionic copper needle can achieve the ultrafast unidirectional transportation of a water droplet in an oil environment, showing a maximum transport velocity of 76.2 mm/s and a transport distance over 33 mm, which were ten times higher than those reported in the previous research. Additionally, the droplet transport mechanism was revealed. The effects of the apex angle and tilt angle of the as-prepared bionic needle and droplet volume on the self-transportation behavior of water droplets were systematically investigated. The results indicated that the transport velocity of the water droplet decreased with the increase of the apex angle of the conical needle, while it increased with the increase of the droplet volume and needle tilt angle. Furthermore, the as-prepared bionic copper needle exhibited excellent fog collection performance with a single copper needle fog collecting efficiency of up to 2220 mg/h, which was 9.7 times that of the original copper needle. In summary, this work provides a simple and novel method to fabricate bionic copper needles for the directional self-transportation of water droplets in air-phase and oil-phase environments as well as efficient fog collection. It shows great application potential in the fields of microfluidics, desalination, and freshwater collection.
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Affiliation(s)
- Yangkai Liu
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Xuqiao Peng
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Linfeng Zhu
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Ruisong Jiang
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Jian Liu
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Chaolang Chen
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
- National United Engineering Laboratory for Advanced Bearing Tribology, Henan University of Science and Technology, Luoyang 471023, China
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14
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Hou H, Wu X, Hu Z, Gao S, Yuan Z. Coalescence-Induced Droplet Jumping on Superhydrophobic Surfaces with Annular Wedge-Shaped Micropillar Arrays. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:18825-18833. [PMID: 38096374 DOI: 10.1021/acs.langmuir.3c02534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
The coalescence-induced droplet jumping on superhydrophobic surfaces has extensive application potential in water harvesting, thermal management of electronic devices, and microfluidics. The rational design of the surface structure can influence the interaction between the droplet and the surface, thereby controlling the velocity and direction of the droplet's jumping. In this study, we fabricate the superhydrophobic surface with annular wedge-shaped micropillar arrays, examine the dynamic behavior of condensate droplets on the surface, and measure the temporal and spatial variations of droplet density, average radius, and surface coverage with wedge-shaped micropillars of varying sizes. In addition, the energy analysis of the coalescence-induced droplet jumping reveals that the two primary factors influencing the jumping are the relative size and position of the droplets and micropillars. Further numerical simulations find that the wedge-shaped micropillars cause an asymmetric distribution of pressure within the droplet and at the solid-liquid contact surface, which generates an unbalanced force driving the droplet in the gradient direction of the wedge-shaped micropillar, causing the droplet to jump off the surface with both vertical and gradient-direction velocities. The capacity of the wedge-shaped micropillar surface to transport droplets in the gradient direction increases and then decreases as the relative size of the droplets and micropillars increases. The relative position of the droplet center-of-mass line perpendicular to the bottom edge of the wedge micropillars' trapezoidal shape is more favorable for droplet transport. This work reveals the influence mechanism of surface structure on the velocity and direction of droplet jumping, and the results can guide the microstructure design of superhydrophobic surfaces, which has significant implications for the application of droplet jumping.
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Affiliation(s)
- Huimin Hou
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Xiaomin Wu
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Zhifeng Hu
- Research Center of Solar Power and Refrigeration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Sihang Gao
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Zhiping Yuan
- Department of Energy and Power Engineering, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
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15
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Zhao S, Ma Z, Song M, Tan L, Zhao H, Ren L. Golden section criterion to achieve droplet trampoline effect on metal-based superhydrophobic surface. Nat Commun 2023; 14:6572. [PMID: 37852950 PMCID: PMC10584815 DOI: 10.1038/s41467-023-42375-3] [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: 06/12/2023] [Accepted: 10/02/2023] [Indexed: 10/20/2023] Open
Abstract
Clarifying the consecutive droplet rebound mechanisms can provide scientific inspirations to regulate dynamic wettability of superhydrophobic surface, which facilitates the practical applications on efficient heat control and active anti-icing. Generally, droplet rebound behaviors are directly affected by surface structure and Weber number. Here, we report a novel "golden section" design criterion to regulate the droplet rebound number determined by the structure spacing, subverting conventional knowledge. Especially, the droplet can continuously rebound for 17 times on the metal-based surface, exhibiting an amazing phenomenon of "droplet trampoline". The droplet rebound number has been experimentally revealed to be closely related to Weber number. We propose novel quantitative formulas to predict droplet rebound number and clarify the coupling effect of the structure spacing and the Weber number on the rebound mechanisms, which can be utilized to establish the regulation criteria of rebound numbers and develop novel metal-based superhydrophobic materials.
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Affiliation(s)
- Shengteng Zhao
- School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China
| | - Zhichao Ma
- School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China.
- Key Laboratory of Bionic Engineering Ministry of Education, Jilin University, Changchun, 130025, China.
- Key Laboratory of CNC Equipment Reliability, Ministry of Education, Jilin University, Changchun, 130025, China.
- Institute of Structured and Architected Materials, Liaoning Academy of Materials, Shenyang, 110167, China.
| | - Mingkai Song
- School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China
| | - Libo Tan
- School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China
| | - Hongwei Zhao
- School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China
- Key Laboratory of CNC Equipment Reliability, Ministry of Education, Jilin University, Changchun, 130025, China
- Institute of Structured and Architected Materials, Liaoning Academy of Materials, Shenyang, 110167, China
| | - Luquan Ren
- Key Laboratory of Bionic Engineering Ministry of Education, Jilin University, Changchun, 130025, China
- Institute of Structured and Architected Materials, Liaoning Academy of Materials, Shenyang, 110167, China
- Weihai Institute for Bionics-Jilin University, Weihai, 264207, China
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Chu J, Tian G, Feng X. Recent advances in prevailing antifogging surfaces: structures, materials, durability, and beyond. NANOSCALE 2023. [PMID: 37368459 DOI: 10.1039/d3nr01767b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
In past decades, antifogging surfaces have drawn more and more attention owing to their promising and wide applications such as in aerospace, traffic transportation, optical devices, the food industry, and medical and other fields. Therefore, the potential hazards caused by fogging need to be solved urgently. At present, the up-and-coming antifogging surfaces have been developing swiftly, and can effectively achieve antifogging effects primarily by preventing fog formation and rapid defogging. This review analyzes and summarizes current progress in antifogging surfaces. Firstly, some bionic and typical antifogging structures are described in detail. Then, the antifogging materials explored thus far, mainly focusing on substrates and coatings, are extensively introduced. After that, the solutions for improving the durability of antifogging surfaces are explicitly classified in four aspects. Finally, the remaining big challenges and future development trends of the ascendant antifogging surfaces are also presented.
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Affiliation(s)
- Jiahui Chu
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang, P. R. China.
| | - Guizhong Tian
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang, P. R. China.
| | - Xiaoming Feng
- College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang, P. R. China.
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17
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Hou H, Wu X, Hu Z, Gao S, Wu Y, Lin Y, Dai L, Zou G, Liu L, Yuan Z. High-speed directional transport of condensate droplets on superhydrophobic saw-tooth surfaces. J Colloid Interface Sci 2023; 649:290-301. [PMID: 37352560 DOI: 10.1016/j.jcis.2023.06.113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/12/2023] [Accepted: 06/16/2023] [Indexed: 06/25/2023]
Abstract
HYPOTHESIS Most droplets on high-efficiency condensing surfaces have radii of less than 100 μm, but conventional droplet transport methods (such as wettability-gradient surfaces and structural-curvature-gradient surfaces) that rely on the unbalanced force of three-phase lines can only transport millimeter-sized droplets efficiently. Regulating high-speed directional transport of condensate droplets is still challenging. Therefore, we present a method for condensate droplet transportation, based on the reaction force of the superhydrophobic saw-tooth surfaces to the liquid bridge, the condensate droplets could be transported at high speed and over long distances. EXPERIMENTS The superhydrophobic saw-tooth surfaces are fabricated by femtosecond laser ablation and chemical etching. Condensation experiments and luminescent particle characterization experiments on different surfaces are conducted. Aided by the theoretical analysis, we illustrate the remarkable performance of condensate droplet transportation on saw-tooth surfaces. FINDINGS Compared with conventional methods, our method improves the transport velocity and relative transport distance by 1-2 orders of magnitude and achieves directional transport of the smallest condensate droplet of about 2 μm. Furthermore, the superhydrophobic saw-tooth surfaces enable multi-hop directional jumping of condensate droplets, leading to cross-scale increases in transport distances from microns to decimeters.
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Affiliation(s)
- Huimin Hou
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Xiaomin Wu
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China.
| | - Zhifeng Hu
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Sihang Gao
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Yuxi Wu
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Yukai Lin
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Liyu Dai
- Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Guisheng Zou
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Lei Liu
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Zhiping Yuan
- Department of Energy and Power Engineering, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China.
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18
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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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Lathia R, Nampoothiri KN, Sagar N, Bansal S, Modak CD, Sen P. Advances in Microscale Droplet Generation and Manipulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2461-2482. [PMID: 36779356 DOI: 10.1021/acs.langmuir.2c02905] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Microscale droplet generation and manipulation have widespread applications in numerous fields, from biochemical assays to printing and additive manufacturing. There are several techniques for droplet handling. Most techniques, however, can generate and work with only a limited range of droplet sizes. Furthermore, there are constraints regarding the workable variety of fluid properties (e.g., viscosity, surface tension, mass loading, etc.). Recent works have focused on developing techniques to overcome these limitations. This feature article discusses advances in this area that cover a wide range of droplet sizes from subpicoliter to microliter.
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Affiliation(s)
- Rutvik Lathia
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Krishnadas Narayanan Nampoothiri
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
- Department of Mechanical Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Chennai 601103, India
| | - Nitish Sagar
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Shubhi Bansal
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
- University College London, London WC1E 6BT, U.K
| | - Chandantaru Dey Modak
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
- Laboratoire de Biophysique et Evolution, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL University, ESPCI Paris, 10 rue Vauquelin, 75005 Paris, France
| | - Prosenjit Sen
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
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20
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Chu C, Zhao Y, Hao P, Lv C. Wetting state transitions of individual condensed droplets on pillared textured surfaces. SOFT MATTER 2023; 19:670-678. [PMID: 36597934 DOI: 10.1039/d2sm01271e] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The ability to realize the self-removal of condensed droplets from a surface is of critical importance for science and applications such as water harvesting and thermal engineering. Despite the enormous interest in micro/nanotextured superhydrophobic materials for high-efficiency condensation, a clear picture of the wetting state transition of condensed droplets is missing, particularly, on a single-droplet level of the order of micrometers. Herein, by varying a substantial parameter space of the contact angle and the geometry of the pillared textures, we have quantified the wetting transition of individual droplets during condensation. We found that a droplet is finally either spontaneously removed from the textures due to a Laplace pressure difference or wets the textures; four different wetting state transition modes have been identified numerically and they are classified in a phase diagram. Simple theories have been constructed to correlate the critical conditions of the wetting state transition to the wettability and geometry of the textures, and they were verified experimentally. We found that the self-removal of condensed droplets benefits from the contact angle and the height of the pillars. These findings not only enhance our fundamental understanding of the wetting state transition of condensed droplets but also allow the rational design of micro/nanotextured water-repellent materials for anti-fogging and anti-wetting.
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Affiliation(s)
- Chenlei Chu
- Department of Engineering Mechanics, AML, Tsinghua University, 100084 Beijing, China.
- Beijing Institute of Spacecraft Environment Engineering, 100094 Beijing, China
| | - Yinggang Zhao
- Department of Engineering Mechanics, AML, Tsinghua University, 100084 Beijing, China.
| | - Pengfei Hao
- Department of Engineering Mechanics, AML, Tsinghua University, 100084 Beijing, China.
- Tsinghua University (School of Materials Science and Engineering)-AVIC Aerodynamics Research Institute Joint Research Center for Advanced Materials and Anti-Icing, Tsinghua University, 100084 Beijing, China
| | - Cunjing Lv
- Department of Engineering Mechanics, AML, Tsinghua University, 100084 Beijing, China.
- Center for Nano and Micro Mechanics, Tsinghua University, 100084 Beijing, China
- State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, 100084 Beijing, China
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21
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Coalescence-induced jumping of in-plane moving droplets: Effects of initial velocity and sideslip angle. Chem Eng Sci 2023. [DOI: 10.1016/j.ces.2022.118247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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