中国物理B ›› 2020, Vol. 29 ›› Issue (11): 114703-.doi: 10.1088/1674-1056/abb664

所属专题: SPECIAL TOPIC — Water at molecular level

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Bin-Ze Tang(唐宾泽)1, Xue-Jia Yu(余雪佳)1, Sergey V. Buldyrev2,, Nicolas Giovambattista3,4,§, Li-Mei Xu(徐莉梅)1,5,¶   

  • 收稿日期:2020-07-27 修回日期:2020-09-01 接受日期:2020-09-09 出版日期:2020-11-05 发布日期:2020-11-03

Energy stored in nanoscale water capillary bridges formed between chemically heterogeneous surfaces with circular patches

Bin-Ze Tang(唐宾泽)1, †, Xue-Jia Yu(余雪佳)1, †, Sergey V. Buldyrev2,, ‡, Nicolas Giovambattista3,4,§, and Li-Mei Xu(徐莉梅)1,5,¶   

  1. 1 International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
    2 Department of Physics, Yeshiva University, 500 West 185th Street, New York, NY 10033, United States
    3 Department of Physics, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
    4 Ph.D. Programs in Chemistry and Physics, The Graduate Center of the City University of New York, New York, NY 10016, United States
    5 Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • Received:2020-07-27 Revised:2020-09-01 Accepted:2020-09-09 Online:2020-11-05 Published:2020-11-03
  • Contact: These authors contributed equally. Corresponding author. E-mail: buldyrev@yu.edu
  • Supported by:
    Project support by the National Natural Science Foundation of China (Grant Nos. 11525520 and 11935002) and the National Key Research and Development Program of China (Grant No. 2016YFA0300901).

Abstract:

The formation of nanoscale water capillary bridges (WCBs) between chemically heterogeneous (patchy) surfaces plays an important role in different scientific and engineering applications, including nanolithography, colloidal aggregation, and bioinspired adhesion. However, the properties of WCB of nanoscale dimensions remain unclear. Using molecular dynamics simulations, we investigate the geometrical and thermodynamic properties of WCB confined between chemically heterogeneous surfaces composed of circular hydrophilic patches on a hydrophobic background. We find that macroscopic capillary theory provides a good description of the WCB geometry and forces induced by the WCB on the confining surfaces even in the case of surface patches with diameters of only 4 nm. Upon stretching, the WCB contact angle changes from hydrophobic-like values (θ > 90°) to hydrophilic-like values (θ < 90°) until it finally breaks down into two droplets at wall separations of ∼ 9–10 nm. We also show that the studied nanoscale WCB can be used to store relevant amounts of energy EP and explore how the walls patch geometry can be improved in order to maximize EP. Our findings show that nanoscale WCB can, in principle, be exploited for the design of clean energy storage devices as well as actuators that respond to changes in relative humidity. The present results can also be of crucial importance for the understanding of water transport in nanoporous media and nanoscale engineering systems.

Key words: water capillary bridge, energy density, morphology transition, hydrophilicity