Preparation of partially carbonized PTFE/PVDF hollow fiber membrane and its oil-water separation performance
The hydrophobic fluorocarbon material,polytetrafluoroethylene(PTFE),poses challenges in film formation through phase conversion.In this work,a PTFE suspension was obtained by dispersing PTFE powder in a polyvinylidene fluoride(PVDF)solution.Firstly,the PTFE/PVDF hollow fiber membrane embryo was prepared using a dry and wet phase conversion method.Subsequently,partial carbonization of the PTFE/PVDF hollow fiber membrane was achieved under a nitrogen atmosphere.The carbonization process of the membrane embryo,surface element and microstructure changes before and after membrane carbonization was studied using thermogravimetric analysis,X-ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM).Finally,the changes in hydrophilicity and oil-water separation performance were evaluated for the membrane.The results revealed that PVDF within the PTFE/PVDF hollow fiber membrane embryo underwent C-H fracture at 360～450 ℃ while partially carbonizing the membrane structure.This led to a reduction in pore size and formation of a continuous and complete microporous structure within the partially carbonized hollow fiber membranes.With 40％PTFE content,after carbonization,the contact angle of the film reached 102° indicating increased hydrophobicity.Moreover,when tested with simulated oil-bearing wastewater containing 10％oil content,these membranes exhibited an impressive permeation flux of 30 L/(m2·h)(Transmembrane differential pressure 0.1 MPa)along with an efficient separation efficiency reaching up to 80％.These results highlight their promising potential for commercial applications in effective oil-water separation.
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维普
