Slippery for scaling resistance in membrane distillation: A novel porous micropillared superhydrophobic surface

WATER RESEARCH

卷:155

Article

Xiao, Zechun^1,2  Zheng, Rui^1,2  Liu, Yongjie^1,3  He, Hailong³  Yuan, Xiaofei⁴  Ji, Yunhui⁵  Li, Dongdong¹  Yin, Huabing⁴  Zhang, Yuebiao³  Li, Xue-Mei¹  He, Tao^1,4 

[1] Chinese Acad Sci, Shanghai Adv Res Inst, Shanghai 201210, Peoples R China

[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[3] ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China

[4] Univ Glasgow, Sch Engn, Glasgow G12 8LT, Lanark, Scotland

[5] Nanjing Univ, Collaborat Innovat Ctr Adv Microstruct, Natl Lab Solid State Microstruct, Coll Engn & Appl Sci,Dept Mat Sci & Engn, Nanjing 210093, Jiangsu, Peoples R China

关键词: Micromolding phase separation;    Surface pattern;    Slippery;    Membrane distillation;    Scaling;    Membrane;   

DOI  :  10.1016/j.watres.2019.01.036

来源: Elsevier

【 摘 要 】

Scaling in membrane distillation (MD) is a key issue in desalination of concentrated saline water, where the interface property between the membrane and the feed become critical. In this paper, a slippery mechanism was explored as an innovative concept to understand the scaling behavior in membrane distillation for a soluble salt, NaCl. The investigation was based on a novel design of a superhydrophobic polyvinylidene fluoride (PVDF) membrane with micro-pillar arrays (MP-PVDF) using a micromolding phase separation (mu PS) method. The membrane showed a contact angle of 166.0 +/- 23 degrees and the sliding angle of 15.8 +/- 3.3 degrees. After CF4 plasma treatment, the resultant membrane (CF4-MP-PVDF) showed a reduced sliding angle of 3.0 degrees. In direct contact membrane distillation (DCMD), the CF4-MP-PVDF membrane illustrated excellent anti-scaling in concentrating saturated NaCl feed. Characterization of the used membranes showed that aggregation of NaCl crystals occurred on the control PVDF and MP-PVDF membranes, but not on the CF4-MP-PVDF membrane. To understand this phenomenon, a slippery theory was introduced and correlated the sliding angle to the slippery surface of CF4-MP-PVDF and its anti-scaling property. This work proposed a well-defined physical and theoretical platform for investigating scaling problems in membrane distillation and beyond. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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