基于纳米TiO_2逐层自组装的聚偏氟乙烯膜亲水化改性研究

Hydrophilic Treatment of PVDF Membrane Based on Layer by Layer Assembling of TiO_2 Nanoparticles

采用逐层自组装方法,利用三乙烯四胺盐对纳米TiO2的吸附作用,把直径约20nm的TiO2颗粒逐层组装到聚偏氟乙烯(PVDF)膜表面,研究了纳米TiO2组装层数对PVDF改性膜接触角的影响,发现当组装层数为1和3时改性PVDF膜初始接触角略有增大,而随着冻结时间延长改性PVDF膜接触角显著减小。当组装层数为5时PVDF改性膜的初始接触角从101.2°显著减小到72.1°,并在1min内被水滴完全浸润,探讨了纳米TiO2组装PVDF改性膜微观结构对其亲水性能的影响机制。研究结果可用于发展分散均匀的高亲水性PVDF膜,提高PVDF膜的抗污染性能并延长其循环使用寿命。

TiO2 nanoparticles with diameter of approximately 20 nm were successfully assembled layer by layeron polyvinylidene fluoride （PVDF） membrane surface via the adsorption of the TiO2 nanoparticles on triethylenetetra-mine so as to improve the uniformity of the dispersion and the efficiency of the hydrophilic treatment of the TiO2 nano-particles. The effect of the assembling layers of the TiO2 nanoparticles on the contact angle of the PVDF membranewas studied. As the number of the assembling layers was 1 and 3, the initial contact angle of the modified PVDFmembrane was slightly increased. With the frozen time prolonged the contact angle of the modified PVDF membranewas significantly decreased. As the number of the assembling layers was 5, the initial contact angle of the modifiedPVDF membrane was significantly decreased from 101.2° to 72.1°. Moreover, the modified PVDF membrane could becompletely infiltrated by water droplets within 1 min. The effect mechanism of the microstructures on the contact an-gle of the TiO2 nanoparticles modified PVDF membrane was also explored. The findings can be used to develop highdispersed hydrophilic PVDF membranes so as to improve their anti-pollution and cycle life in filtration applications.