Perfluorinated superhydrophobic and oleophobic SiO2@PTFE nanofiber membrane with hierarchical nanostructures for oily fume purification

Polytetrafluoroethylene (PTFE) nanofiber membranes have been widely used in various air purification applications attributed to their excellent thermal and chemical stabilities. However, in oily fume purification, oil aerosols can easily permeate through the oleophilic membrane, which may lead to pore blocking, and increased filtration resistance and energy consumption, finally reducing the filtration efficiency and lifespan of the membrane. Herein, we report a hierarchical SiO2@PTFE nanofiber membrane by coaxial electrospinning of SiO2 nanoparticle dispersion as the shell spinning solution and PTFE emulsion as the core spinning solution, followed by in-situ surface grafting of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane. The prepared amphiphobic membrane has both superhydrophobicity and oleophobicity with the water and oil contact angles of 173 degrees and 134 degrees, respectively. It possesses uniform pore structures, high gas permeability (697 m(3) m(-2) h(-1) kPa(-1)), excellent oily fume filtration efficiency ((>)99%), as well as a low pressure drop (2.5 kPa) during 60-min filtration. Furthermore, our perfluorinated amphiphobic SiO2@PTFE nanofiber membrane exhibits good reusable and stable properties. This work opens a versatile approach to design efficient functionalized membranes in the field of oily fume purification.

聚四氟乙烯（PTFE）纳米纤维膜由于其出色的热稳定性和化学稳定性而已广泛用于各种空气净化应用中。但是，在油烟净化中，油雾很容易透过亲油膜，这可能导致孔堵塞，并增加了过滤阻力和能耗，最终降低了膜的过滤效率和使用寿命。在本文中，我们报告了分层SiO2 @ PTFE纳米纤维膜，方法是将SiO2纳米颗粒分散液作为壳纺丝溶液，将PTFE乳液作为芯纺丝溶液进行同轴电纺丝，然后进行1H，1H，2H，2H-全氟辛基三甲氧基硅烷的原位表面接枝。所制备的两性膜具有超疏水性和疏油性，其水和油的接触角分别为173度和134度。它具有均匀的孔结构，高的气体渗透性（697 m（3）m（-2）h（-1）kPa（-1）），出色的油烟过滤效率（（>）99％）和较低的60分钟过滤期间的压降（2.5 kPa）。此外，我们的全氟两亲性SiO2 @ PTFE纳米纤维膜表现出良好的可重复使用和稳定的性能。这项工作为在油烟净化领域设计高效的功能化膜开辟了一种通用方法。

Published: 2020

Journal ：JOURNAL OF MEMBRANE SCIENCE

Impact Factor：7.484

Paper link: https://www.sciencedirect.com/science/article/abs/pii/S0376738819317090