Preparation of a hydrophobically enhanced antifouling isotactic polypropylene/silicone dioxide flat‐sheet membrane via thermally induced phase separation for vacuum membrane distillation |
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| Authors: | Na Tang Huaiyuan Han Lina Yuan Lei Zhang Xuekui Wang Penggao Cheng |
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| Affiliation: | 1. College of Marine Science and Engineering, Tianjin University of Science & Technology, Tianjin, People's Republic of China;2. Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin, People's Republic of China |
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| Abstract: | Isotactic polypropylene (iPP) hydrophobic flat‐sheet membranes were fabricated for use in vacuum membrane distillation (VMD) through a thermally induced phase‐separation process with dispersing hydrophobically modified SiO2 nanoparticles in the casting solution to achieve a higher hydrophobicity and to sustain a stable flux in VMD. The contact angle (CA) measurements indicated that the incorporation of nano‐SiO2 into a casting solution mixture containing 20 wt % iPP had a 20.9% higher CA relative to that of SiO2‐free membranes. The addition of nano‐SiO2 also induced morphological changes in the membrane structure, including changes in the pore size distribution, porosity, and suppression of macrovoids. The pore size distribution of the iPP–SiO2 membranes became narrower compared with that of the SiO2‐free membranes, and the porosity also improved from 35.45 to 59.75% with SiO2 addition. The average pore size and maximum pore size of the iPP–SiO2 membranes both decreased. The ability of the membranes to concentrate an astragalus aqueous solution (a type of traditional Chinese medicine) with VMD was investigated. The surface hydrophobicity and antifouling performance of the iPP–SiO2 membranes improved with nano‐SiO2 addition to the membrane casting solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42615. |
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| Keywords: | membranes nanoparticles nanowires and nanocrystals polyolefins porous materials properties and characterization |
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