聚砜超滤膜结构对铸膜溶液性质的依赖性

THE DEPENDENCE OF STRUCTURE OF POLYSULFONE ULTRAFILTRATION MEMBRANE ON THE PROPERTIES OF CASTING SOLUTION

考察了聚砜(PSF)在N-甲基吡咯烷酮(NMP)、N,N-二甲基乙酰胺(DMAc)、N,N-二甲基甲酰胺(DMF)三种溶剂中的链尺寸、铸膜液的零切粘度和浊点等,用场发射扫描电镜(SEM)对膜的表面形貌和截面结构进行了表征。结果表明,PSF在三种溶剂中链尺寸大小为NMP>DMAc>DMF,与PSF在三种溶剂中耐非溶剂水的能力顺序相同。当PSF浓度为13%时,相对粘度和流动活化能大小的顺序为DMF>DMAc>NMP。以DMF为溶剂制备的膜截面为具有密度梯度的网络状孔,而以DMAc和NMP为溶剂得到的膜为指状孔。不同溶剂对膜结构、水通量和截留率有显著影响。

Using NMP,DMAc,DMF,as solvents,the shape ofpolysulfone chain in different solvents, cloud point, zero shearing viscosity and flow activition energy of casting solution were investigated. The ultrafiltration membranes were characterized by scanning electron microscope. The experimental results showed that the size of the polysulfone is NMP〉DMAc〉DMF in three solvents. The degree of cloud point was NMP〉DMAc 〉DMF,and the relative viscosity and flow activation energy of casting solution was NMP〉DMAc〉DMF,when the concentration of PSF was 13%. The structure of membrane cross-section was density-grads when using DMF as a solvent,and the cross section of membranes were finger-like structure when using DMAc and NMP as solvents. Effect of different solvents on membrane morphology,pure water flux and rejection of membrane Were prominence.