聚偏氟乙烯光致热纳米纤维膜的制备及其性能

为解决减压膜蒸馏过程中温度极化现象造成膜渗透通量下降的问题,以聚偏氟乙烯(PVDF)为成膜聚合物,引入具有红外致热效应的功能性纳米掺锑二氧化锡(ATO),采用静电纺丝技术制备了PVDF/ATO纳米纤维膜,并对其进行热压处理优化纤维结构和孔径,然后探讨ATO质量分数、热压温度对纤维膜结构和性能的影响,并测试了红外辐照下纤维膜的致热效果和膜蒸馏性能。结果表明:PVDF/ATO纳米纤维膜经170 ℃热压处理后,具有更优异的综合性能;当ATO质量分数为3%时,PVDF/ATO纳米纤维膜经120 s红外辐照后,表面温度升高了40 ℃以上,其膜蒸馏渗透通量相对于原膜从12 L/(m ²·h)提高到22 L/(m ²·h),并且在5 h运行时间内,截盐率保持在99%以上。

Preparation and properties of polyvinylidene fluoride photothermal nanofiber membrane

In order to solve the problem of the decrease in the membrane permeate flux caused by temperature polarization in the process of vacuum membrane distillation (VMD), polyvinylidene fluoride (PVDF) was used as a membrane-forming polymer, and functional antimony doped tin oxide (ATO) with the infrared-induced thermal effect was introduced. PVDF/ATO nanofiber membranes were prepared by electrospinning and then subjected to heat pressing treatment to optimize the fiber structure and pore size. Then, the influences of ATO addition and heat pressing temperature on the morphologies and properties of the membranes were investigated. The results show that the PVDF/ATO nanofiber membrane has better physical properties after heat pressing treatment at 170 ℃. When the ATO addition amount is 3%, the surface temperature of the PVDF/ATO nanofiber membrane increases by 40 ℃ after infrared irradiation for 120 s, the permeate flux of VMD increases from 12 L/(m ²·h) to 22 L/(m ²·h), and the salt rejection remains above 99% during the operation for 5 h.