Polyacrylonitrile/polyimide composite sub-micro fibrous membranes for precise filtration of PM0.26 pollutants

Particulate matter (PM) pollution has enormously threatened ecosystem and public health. Among various air filtration medium, fibrous ones are very attracting and promising, with an array of advantages such as high specific surface area, and good internal connectivity. Even so, the large-scale fabrication of fibrous filtration materials still remains challenging. Here, three-dimensional polyacrylonitrile/polyimide (PAN/PI) composite sub-micro fibrous membranes were fabricated facilely via free surface electrospinning for precise filtration of PM0.26 pollutants, where the waste PI short fibers were utilized as raw material. The resultant composite fibrous membranes, featuring thin fiber diameter (similar to 150 nm), low areal density (<0.8 g m(2)), large porosity, and highly tortuous airflow channels with uniform pore size distribution, possessed excellent mechanical property with tensile strength of 4.95 MPa (twice that of pristine PAN), high thermal durability as well as remarkable filtration performance for ultrafine NaCl aerosol particles (<= 0.26 mu m) even after multiple filtration tests at high airflow velocity of 14.1 cm s(-1). The deepened aperture channels inside three-dimensional sub-micro fibrous membranes are tortuous enough for capturing ultrafine PMs from the airstream mainly via diffusion, interception, and impaction mechanisms, and the reported large-scale fabrication of cost-effective homogeneous PAN/PI fibrous filter media is promising for industrial production and commercial applications. (C) 2020 Elsevier Inc. All rights reserved.

颗粒物（PM）污染已严重威胁着生态系统和公共健康。在各种空气过滤介质中，纤维介质非常吸引人并很有前景，具有一系列优势，例如高比表面积和良好的内部连通性。即使这样，纤维过滤材料的大规模制造仍然具有挑战性。在这里，通过自由表面静电纺丝方便地制造了三维聚丙烯腈/聚酰亚胺（PAN / PI）复合亚微纤维膜，用于精确过滤PM0.26污染物，其中以废PI短纤维为原料。所得复合纤维膜具有纤细的纤维直径（约150 nm），低的面密度（<0.8 gm（2）），大的孔隙率和具有均匀孔径分布的高度曲折的气流通道，具有出色的机械性能和拉伸强度即使在14.1 cm s（-1）的高风速下进行多次过滤测试后，其仍具有4.95 MPa（原始PAN的两倍），高热耐久性以及超细NaCl气溶胶颗粒（<= 0.26μm）的出色过滤性能。三维亚微纤维膜内部加深的孔道非常曲折，足以通过扩散，拦截和撞击机制从气流中捕获超细颗粒物，并且据报道大规模制造了具有成本效益的均质PAN / PI纤维过滤器媒体在工业生产和商业应用方面很有前景。 （C）2020 Elsevier Inc.保留所有权利。

Published: 2020

Journal ：JOURNAL OF COLLOID AND INTERFACE SCIENCE

Impact Factor：7.489

Paper link: https://www.sciencedirect.com/science/article/abs/pii/S0021979720306913