Fabrication of super-hydrophobic polypropylene hollow fiber membrane and its application in membrane distillation

The main aim of the current study is to prepare super-hydrophobic polypropylene hollow fiber membranes. However, polypropylene hollow fiber membrane surface is very smooth and difficult to attach silica particles. To solve this problem, a method including combined use of silica particles and polypropylene solution is used to preparation the super-hydrophobic coatings. The collosol mixed by the silica particles and PP particles were coated to the membrane surface. Then the membrane was modified by 1H,1H,2H,2H-Perfluorooctyltriethoxysilane (POTS) that exhibited a super-hydrophobic surface with a static water contact angle of 157°. Surface elemental analyses of membrane were characterized by XPS and surface analyses (FT-IR, FESEM, AFM, contact angle measurements and MIP). In addition, membrane distillation experiments of NaCl solutions were carried out in unmodified and modified polypropylene hollow fiber membrane. The results indicated that, compared with the untreated membranes, the modified membranes had higher flux and rejection.