双凝固浴法制备高度疏水PVDF杂化微孔膜

摘要

Using N,N dimethylacetamide (DMAc) as solvent and modified TiO2 nanoparticles as nonsolvent additive,polyvinylidene fluoride (PVDF)membranes with highly hydrophobic surface and high overall porosity were fabricated by a modified NIPS method with dual-bath coagulation process.The effects of type of the first coagulant on precipitation rate,membrane morphology and wettability were investigated.It was shown that,when using isopropanol as the first coagulant and water as the second coagulant,the precipitation rate of casting solution was lower and the resulting membranes with high porosity and rough top surface with crystallization showed a high water contact angle of 130°.However,if modified TiO2 nanoparticles were added into the casting solution,a high increase of gas flux of PVDF membrane could be led to while keeping a high hydrophobicity.Moreover,an analysis to the reason that the high hydrophobicity could be kept using X-Ray energy spectrum and infrared spectroscopic analysis was provided.%以N,N二甲基乙酰胺(DMAc)为溶剂,以改性纳米TiO2粒子为添加剂,采用双凝固浴法制备高度疏水PVDF多孔膜,并考察第1凝固浴种类对PVDF膜凝胶分相速率、膜结构及疏水性的影响.结果表明:以异丙醇为第1凝固浴,水为第2凝固浴,铸膜液的凝胶分相速率较慢,所得膜的孔隙率较大,具有山峦状起伏及结晶微结构的粗糙膜表面,其水接触角可达130°,显示出高度疏水性；在铸膜液中加入适量改性纳米TiO2粒子,可使PVDF膜的气通量大幅提高,而疏水性并无下降；采用X射线能谱和红外光谱分析技术,对PVDF膜表面高度疏水性能够保持的原因进行了分析.