聚偏氟乙烯超疏水分离膜的制备

采用溶液涂覆-浸没相分离法对聚偏氟乙烯膜(PVDF)进行表面复合改性,制备了超疏水分离膜。初步考察了涂覆液中PVDF固含量和涂覆条件(浸泡时间、预蒸发时间、凝固浴组成和凝固浴温度)对复合膜疏水性能的影响。实验结果表明,当涂覆液中PVDF含量为1.88%(质量分数)时,膜丝有最大接触角136°;复合膜的接触角随浸泡时间的延长呈现先增大后减小的趋势,当浸泡时间为40s时,接触角最大,达到133°;在较短时间内(0～5s),预蒸发时间对复合膜的接触角影响不大;复合膜的接触角随着凝固浴中DMAc含量的增加而逐渐减小,随着凝固浴温度的增大而增大,当凝固浴温度为65℃时,膜表面的接触角增至153°。

Preparation of super-hydrophobic polyvinylidene fluoride separation membrane

The surface of polyvinylidene fluride(PVDF) hollow fiber membranes was modified by non-solvent induced phase separation and then obtained super-hydrophobic separation membranes.The influences of PVDF percentage composition in the coating solution and coating conditiongs(such as:soaking time,pre-evaporation time,coagulation bath composition and coagulation bath temperature) were researched.The results show that composite membranes had the largest contact angle that was 136°when PVDF solid content is 1.88wt% in the coating solution;with the extension of soaking time,the contact angle of composite membrane at first increase and then decreased,when the soaking time is 40s,the contact angle reach to a maximum of 133°;in a relatively short period of time(0-5s),the pre-evaporation time have little effect on the contact angle of composite membrane;contact angle of composite membrane decrease with DMAc concentration in the coagulation bath increase,but increase with the coagulation bath temperature increase,when the coagulation bath temperature is 65℃,the membrane surface contact angle increase to 153°.