【摘要】 利用倒相法在纯水和φ(ethano l)=20%、φ(ethano l)=40%的乙醇/水凝胶浴中分别制备了聚偏氟乙烯(PVDF)多孔膜,通过SEM,DSC对这些薄膜进行了分析表征。结果表明纯水凝胶浴中所成膜为指状多孔膜,随着凝胶浴乙醇体积分数的增加,膜指状大孔逐渐消失,在φ(ethano l)=40%的乙醇/水凝胶浴中转变为海绵状多孔膜;指状多孔膜和海绵状多孔膜熔点相对于原料分别提高了3.9℃和3.5℃,而结晶度相对于原料分别提高了16.1%和13.5%。对成膜机理和结晶度变化的原因进行了分析。更多还原

【Abstract】 Porous poly(vinylidene fluoride)(PVDF) membranes were prepared by phase inversion method in pure water and ethanol/water coagulation baths of φ(ethanol)=20% and φ(ethanol)=40%,and these membranes were studied by SEM and DSC.The results indicate the membrane prepared in pure water coagulation bath exhibits fingerlike structure,with an increase of the volume fraction of ethanol in coagulation bath leads to a reduction of fingerlike cavities,and in ethanol/water coagulation bath of φ(ethanol)=40% exhibits spongelike structure;the melting points of the fingerlike and spongelike membrane increase by(3.9) ℃ and(3.5) ℃ compared to that of raw material respectively,and the crystallinity of the two type membranes increases by(16.1%) and(13.5%) respectively.The mechanism of membrane formation and the change of PVDF crystallinity were discussed.更多还原