环境相对湿度对高疏水性PVDF膜结构与性能的影响  

Effects of relative humidity on morphology and performance of PVDF porous membrane

作　　者：王志英[1] 吴晓君[1] 刘启东[2] 杨振生[1] 

机构地区：[1]河北工业大学化工学院,天津300130 [2]天津市普莱特科技发展有限公司,天津300384

出　　处：《功能材料》2013年第16期2320-2323,2328,共5页Journal of Functional Materials

基　　金：河北省自然科学基金资助项目(B2008000016);河北省教育厅科研计划资助项目(Z2008309)

摘　　要：以聚偏氟乙烯(PVDF)/N,N-二甲基乙酰胺(DMAc)/辛醇/水为制膜体系,采用粗糙基底辅助相转化法制备PVDF多孔膜。考察了环境相对湿度对膜结构、透过性能和表面浸润性的影响。结果表明,环境相对湿度增大,膜表面孔数量增多,膜底面聚合物球晶生长更为充分,表面侧致密皮层减薄,在高湿度环境下,成为几乎对称的海绵状断面结构;当环境相对湿度低于50%时,膜的气通量几乎为0,相对湿度高于50%条件下,膜的气通量随相对湿度增大而增大;膜底面的疏水性随相对湿度的增大变化不甚明显,水接触角均在130°以上。Hydrophobic polyvinylidene fluoride （PVDF） membrane were tailored by non-solvent induced phase inversion assisted with coarse substrate. N,N-dimethylacetamide（DMAc） and octanol were used as solvent and non-solvent addition, respectively. In this method, the polymer dope solution was cast on coarse substrate and the film was put on the balance placed in a chamber for a fixed time interval, where temperature and humidity were controlled. Then, it was immersed into water coagulation bath. The effects of relative humidity on the morphology, permeability and hydrophobic of PVDF membrane were investigated. As the humidity in the gas phase increased, the number of top surface pores and pore size increased and the crystalline particles of the bot- tom surface grew better. In addition, it was found that the thickness of skin layer near top surface decreased with increasing humidity. At higher humidity condition, the dense skin layer disappeared and exhibited sym- metric spongy structure. There was little nitrogen flux in the case of lower humidity of under 50°, whereas the nitrogen flux increased obviously with increasing humidity in the case of humidity higher than 50°. With the increase of the humidity, the hydrophobic of the bottom surface had no obvious change, and the water contact angles of the membranes were all higher than 130°.

关 键 词：聚偏氟乙烯 膜 相对湿度 透过性能 疏水性 

分 类 号：TQ028.8[化学工程]