TiO_2溶胶改性PVDF中空纤维超滤膜的亲水化研究

Hydrophilic study of PVDF hollow fiber UF membrane modifyed by TiO_2 sol

通过PVDF铸膜液中添加TiO2溶胶,采用相转化法制备了PVDF-TiO2中空纤维共混超滤膜,并经SEM-EDX、亲水性与超滤测试、以及抗污染实验等手段研究了TiO2溶胶对PVDF中空纤维膜的结构和亲水性能的影响.结果表明:当TiO2含量为4.5%时,膜的亲水性能较好,抗污染性有明显的改善,在保持截留率基本不变的情况下,纯水通量明显提高,由108L/(m2.h)提高到244 L/(m2.h);但过高的TiO2含量会产生严重的纳米颗粒团聚现象而造成膜的各项性能指标下降.

Through adding TiO2 sol into PVDF dope solutions, PVDF- TiO2 hollow fiber UF blend membranes were prepared by phaseinversion method. The influences of TiO2 sol on the morphologies and hydrophilic properties of such PVDF - TiO2 membranes were investigated through the methods of SEM - EDX, hydrophilicity and UF experiments, as well as anti - fouling tests. The results showed that at 4.5 % TiO2, the blend membranes exhibited extraordinary hydrophilicity and anti- fouling ability, and the permeability was increased drastically from 108 L/（m^2·h） to 244 L/（m^2·h） combining with retention nearly unchanged. However, higher TiO2 content caused the serious aggregation of nanoparticles and resulted in the performance decline of PVDF - TiO2 membranes.