TiO_2/酚酞聚醚砜复合超滤膜的研究

Study of TiO_2/PES-C ultrafiltration membranes

采用浸没沉淀相转化法制备了TiO2/酚酞聚醚砜复合膜,系统地研究了溶剂种类、TiO2添加量等条件对TiO2/PES-C膜结构与性能的影响.结果表明:以DMAc为溶剂时液-液分层速度较慢,得到的超滤膜在添加TiO2前后透过性能均较好,截留率高.与不含纳米TiO2的PES-C膜相比,含TiO2的TiO2/PES-C复合膜的超滤性能、亲水性和抗蛋白污染性都有了显著的改善.当TiO2添加量小于3%时,膜表面Ti元素的含量随着TiO2添加量的增加而增加,其透过性能和抗污染性能也在提高,纳米TiO2/PES-C复合膜具有不对称的断面结构和致密的皮层,亚孔层具有更好的贯通性;当TiO2添加量超过5%时,表面明显分布有大量小孔,其断面结构则表现为皮层变厚,亚孔层消失,只存在指状大孔结构,同时膜的透过性能有所降低.在膜的抗污染试验中,通过牛血清白蛋白溶液连续运行和接触角测定实验表明,TiO2的加入有助于减缓膜在运行过程中通量的衰减,增强了膜的抗蛋白污染性和亲水性.当TiO2水溶液添加量为3%时,TiO2/PES-C复合膜的通量达到最大,亲水性最好,且具有较好的抗蛋白污染性.

The paper studied the effects of TiO2 nanoparticles on the structure and performance of TiO2/PES- C UF membranes. The velocity of liquid liquid separation in the DMAc solution was slow. Meanwhile, the UF membranes exhibited high permeability and rejection. Compared to the neat PES - C UF membrane, the TiO2 nanoparticles could improve the water fluxes, BSA aqueous fluxes, hydrophilicity and antifouling property of the PES- C membrane. The morphologies of membrane surface and cross - section were examined by SEM. The high TiO2 concentration （95 % ） produces a considerable number of large surface pores. The fingerlike pores became run through at low TiO2 concentration and then the thickness of skin layer increased at high TiO2 concentration （≥5 % ）. At 3 % TiO2 content, the composite membranes held excellent water permeability, hydrophilicity, and good anti - fouling ability with almost unchanged retentions. However, high TiO2 content resulted in the performance decline of TiO2/PES- C membrane. The experimental results show that the composite UF membrane has good separation performance and offers a strong potential for possible use as a new type of anti - foul- ing UF membrane.