TiO_2/PVDF编织管改性复合膜的制备及性能

Hydrophilic modification and properties of TiO_2/PVDF woven tubal hollow fiber composite membrane

以PET编织管为内支撑层,以PVDF为膜基材、纳米TiO_2粒子为亲水化改性剂,利用涂覆-浸没凝胶相转化法制备得到具有高强度高通量的PVDF-PET编织管改性复合膜。考察PVDF含量对涂覆及膜表面形貌和膜性能的影响。以水通量、抗污染性等为评价指标,确定改性膜中纳米TiO_2颗粒的最佳投入比。结果表明：PVDF-PET编织管中空纤维膜在PVDF耗量、过滤面积和机械强度上较传统中空纤维膜具有更大优势。当铸膜液中PVDF含量在10%～14%时,膜表面平整光滑,涂覆均匀;PVDF含量为12%时,复合膜孔隙率最大。由QCM-D检测分析可知,PVDF/TiO_2膜与纯PVDF膜相比,牛血清蛋白（BSA）吸附量减少;TiO_2含量为1%时复合膜通量衰减率最低,抗污染性最强,通量最大,复合膜整体性能更为优异。

A tubal PVDF-PET woven, modified composite membrane with high strength and water flux was prepared using PET woven tubal as a support layer and PVDF as a film base material. In this study, nano-TiO2 particles were used for hydrophilization modifiers with a coating and phase separation technology. The effect of the PVDF concentration of the casting solution on the coating, surface morphology, and membrane performance were investigated. Water flux, antifouling ability, and other parameters were used as evaluation indexes to determine the optimal dosing ratio of nano-TiO2 particle to modified membrane. The results revealed that a tubal PVDF-PET woven, hollow fiber membrane has greater advantages in terms of PVDF consumption, filtration area, and me- chanical strength, when compared to the conventional hollow fiber membrane. When the concentration of PVDF in the casting solution was from 10% to 14% , the surface of the membrane is smooth, and has a uniform coating layer; maximum membrane porosity is achieved at 12% PVDF. Second, analysis of the QCM-D detection indica- ted that the PVDF/TiO2 composite membrane has a lower BSA adsorption capacity than pure PVDF. At 1% TiO2, the composite membrane has the lowest flux decline rate, the strongest antifouling ability, and the largest flux, thereby producing an excellent overall performance.