静电纺聚四氟乙烯/二氧化钛光催化纳米纤维膜的制备及其应用

针对光催化剂二氧化钛(TiO₂)难回收、传统载体材料性能不稳定等问题,以聚四氟乙烯(PTFE)为成膜聚合物,以聚乙烯醇(PVA)为纺丝载体,引入纳米光催化剂TiO₂,采用乳液静电纺丝法制备PTFE/PVA/TiO₂初生纤维膜,然后经烧结得到负载型PTFE/TiO₂光催化纳米纤维膜。通过形貌观察、孔径、孔隙率以及疏水性能测试,考察TiO₂质量分数对纤维膜结构与性能的影响。结果表明:随着TiO₂固含量的增加,纤维膜直径均匀性有所降低,平均孔径增大;将纤维膜用于减压膜蒸馏实验,通量最高达35 L/(m²·h),截盐率稳定在99.98%以上;在光催化降解质量浓度为10 mg/L的亚甲基蓝染料水溶液过程中,经紫外线照射5 h后,染料降解率达99%;经重复使用后,PTFE/TiO₂纳米纤维膜仍能保持良好的结构与光催化性能。

Electrospun poly(tetrafluoroethylene)/TiO2 photocatalytic nanofiber membrane and its application

In order to solve the difficult recovery of photocatalyst titanium dioxide (TiO₂) and unstable performance of the conventional carrier materials, poly(tetrafluoroethylene) (PTFE) was used as a stable TiO₂ carrier, and polyvinyl alcohol (PVA) was used as the spinning carrier. The PTFE/PVA/TiO₂ precursor fiber membrane was obtained by emulsion electrospinning, and then the PTFE/TiO₂ photocatalytic nanofiber membrane was obtained after sintering. The effects of the amount of titanium dioxide on the structure and properties of the membranes were investigated by membrane morphology observation, pore size, porosity and hydrophobicity. The results show that with the increase of TiO₂ solid content, the uniformity of membrane fiber diameter decreases and the pore size increases. The membrane was used in vacuum membrane distillation experiment. The flux is up to 35 L/(m²·h) and the desalination rate is over 99.98%. At the same time, the membrane was used for photocatalytic degradation of methylene blue dye aqueous solution (concentration of 10 mg/L). The degradation ratio reaches 99% after 5 h UV irradiation. After reuse, PTFE/titanium dioxide nanofiber membranes still maintain good membrane structure and photocatalytic performance.