Springtail-inspired omniphobic slippery membrane with nano-concave re-entrant structures for membrane distillation

Jiaxin Guo; Mengnan Jiang; Xiaolu Li; Muhammad Usman Farid; Bhaskar Jyoti Deka; Baoping Zhang; Jiawei Sun; Zuankai Wang; Chunhai Yi; Pak Wai Wong; Sanghyun Jeong; Boram Gu; Alicia Kyoungjin An

doi:10.1038/s41467-024-52108-9

Springtail-inspired omniphobic slippery membrane with nano-concave re-entrant structures for membrane distillation

Nat Commun. 2024 Sep 5;15(1):7750. doi: 10.1038/s41467-024-52108-9.

Authors

Jiaxin Guo^{1

2}, Mengnan Jiang³, Xiaolu Li², Muhammad Usman Farid^{2

4}, Bhaskar Jyoti Deka^{5

6}, Baoping Zhang⁷, Jiawei Sun², Zuankai Wang⁷, Chunhai Yi¹, Pak Wai Wong², Sanghyun Jeong⁸, Boram Gu⁹, Alicia Kyoungjin An^{10

11}

Affiliations

¹ School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
² School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong, China.
³ Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, School of Energy and Power Engineering, Dalian University of Technology, Dalian, China.
⁴ Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
⁵ Department of Hydrology, Indian Institute of Technology Roorkee, Haridwar, Uttarakhand, 247667, India.
⁶ Centre for Nanotechnology, Indian Institute of Technology Roorkee, Haridwar, Uttarakhand, 247667, India.
⁷ Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
⁸ Department of Civil and Environmental Engineering, Environmental Engineering, Pusan National University, Pusan, South Korea.
⁹ School of Chemical Engineering, Chonnam National University, Gwangju, South Korea.
¹⁰ School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong, China. alicia.kjan@ust.hk.
¹¹ Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. alicia.kjan@ust.hk.

Abstract

Omniphobic membranes, due to their exceptional properties, have drawn significant attention for overcoming the bottleneck in membrane distillation (MD) technology. This study demonstrates an innovative method for fabricating an omniphobic membrane that is simple and facile compared to other methods such as wet/dry etching and photolithography. The surface morphology of springtails was imitated using electrospraying technique to coat a polyvinylidene fluoride substrate with concave-shaped polystyrene beads that were successfully developed by controlling the electrical traction (voltage) and air resistance (humidity). Then, the lipid coating of springtail surfaces was mimicked by dip-coating the membrane in a low-toxicity short-chain perfluoropolyether lubricant. The concave structure's tiny air pockets increased membrane hydrophobicity significantly, indicated by the fact that the first round of water bouncing took only 16.3 ms. Finally, in MD treatment of seawater containing 1.0 mM sodium dodecyl sulfate, the optimized omniphobic membrane maintained a stable 99.9% salt rejection rate.

Abstract

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