Super-hydrophobic membranes of poly(vinylidene fluoride) blended with specialized co-polymers for oil-water separation

摘要

Non-woven super-hydrophobic fiber membranes have potential applications in oil-water separation. The membranes are blends comprising poly(vinylidene fluoride), PVDF, and random copolymers of poly(methyl methacrylate), PMMA, and 1H,1H,2H,2H-perfluorodecyl methacrylate, PFDMA, sulfobetaine methacrylate, SBMA, and sulfobetaine-2-vinylpyridine, SB2VP. PVDF imparts mechanical strength to the membrane, while the copolymers enhance membrane roughness and hydrophobicity. Blend composition was varied by controlling the PVDF content of the blends. Non-woven fiber membranes were obtained by electrospinning solutions of PVDF and the copolymers, at 15%-20% w/v in a mixed solvent, N,N-dimethylacetamide/acetone, 7/3 v/v. The crystallinities of the blends were studied using wide angle X-ray diffraction and differential scanning calorimetry. The degradation profiles were determined using thermogravimetry. The glass transition and degradation temperatures varied systematically with the composition of the blends. The hydrophobicity of the fibrous membranes was determined using contact angle testing and with the addition of the co polymers, showed significant increase from neat PVDF. Future work will be reported on the oil-water filtration capability of these membranes.