Li Dawei, Shen Ying, Wang Lanlan, Liu Feng, Deng Bingyao, Liu Qingsheng
Key Laboratory of Eco-Textiles (Ministry of Education), Nonwoven Technology Laboratory, Jiangnan University, Wuxi 214122, China.
Polymers (Basel). 2020 Oct 27;12(11):2494. doi: 10.3390/polym12112494.
Electrospun polymer membranes were considered to be promising materials for fine particulate matter (PM) filtration. However, the poor mechanical properties of the electrospun membrane restricted their application for pressure-driven air filtration. Herein, strength-enhanced electrospun polyimide (PI) membranes were demonstrated via a synergistic approach. Solvent-vapor treatment was utilized to introduce extra bonding at the cross points of PI nanofiber, while SiO nanoparticles (SiO NPs) were used to reinforce the body of nanofibers. The mechanical strength and filtration performance of hybrid membranes could be regulated by adjusting the quantity of SiO NPs. The tensile strength of the pure PI membrane was increased by 33% via adding 1.5% SiO NPs, which was further promoted by 70% after solvent-vapor treatment. With a slight reduction in pressure drop (6.5%), the filtration efficiency was not greatly suppressed by welding the SiO NP hybrid PI nanofibers. Moreover, the welded composite filter showed high particulate (0.3-1.0 μm) filtration efficiency (up to nearly 100%) and stable pressure drop throughout the 20 tested filtration cycles.
静电纺丝聚合物膜被认为是用于细颗粒物（PM）过滤的有前景的材料。然而，静电纺丝膜较差的机械性能限制了它们在压力驱动空气过滤中的应用。在此，通过一种协同方法展示了强度增强的静电纺丝聚酰亚胺（PI）膜。利用溶剂蒸汽处理在PI纳米纤维的交叉点引入额外的键合，同时使用SiO纳米颗粒（SiO NPs）增强纳米纤维主体。通过调节SiO NPs的量可以调控复合膜的机械强度和过滤性能。通过添加1.5%的SiO NPs，纯PI膜的拉伸强度提高了33%，在溶剂蒸汽处理后进一步提高了70%。在压降略有降低（6.5%）的情况下，焊接SiO NP复合PI纳米纤维后过滤效率没有受到很大抑制。此外，焊接后的复合过滤器在20个测试过滤循环中表现出高颗粒（0.3 - 1.0μm）过滤效率（高达近100%）和稳定的压降。
