A silk fibroin based green nano-filter for air filtration

Fibrous air filters fabricated by electrospinning have proved to be an effective approach among the various strategies for PM2.5 removal. However, in the electrospinning process, the large amounts of toxic organic solvents usually evaporate into the atmosphere and disposing of these used polymer-based air filters would leave further pollution in the environment. Here, we report on the fabrication of a silk fibroin based nanofiber air filter with robust filtration performance via a green electrospinning process. Silk worm cocoons were degummed and dialyzed against water to form the silk fibroin solution and then the silk fibroin nanofiber membranes were fabricated by electrospinning with the help of polyethylene oxide. Moreover, special attention was paid to the morphological evolution of the pollutants captured by the nanofiber nets during the filtration process. It was discovered that the inherent properties of silk fibroin play a key role in improving the filtration performance. Benefiting from the richness of functional groups, the resultant silk fibroin fibrous membranes exhibited a high filtration efficiency of 99.99% with a relatively low air resistance of only 75 Pa, leading to an obvious higher quality factor. Due to the biodegradability of silk fibroin, the membranes are disposable after use. We believe that the methodology and results presented here will not only provide a novel perspective for air filtration, but also pave the way for producing a safe and clean air filtration system.

在静电消除PM2.5的各种策略中，由静电纺丝制造的纤维状空气过滤器已被证明是一种有效的方法。但是，在静电纺丝过程中，通常会向大气中蒸发大量有毒的有机溶剂，处理这些用过的基于聚合物的空气滤清器会对环境造成进一步的污染。在这里，我们报告了一种通过绿色静电纺丝工艺制造的具有强大过滤性能的丝素蛋白纳米纤维空气过滤器。将蚕茧脱胶并在水中透析以形成丝素蛋白溶液，然后在聚环氧乙烷的帮助下通过静电纺丝法制备丝素蛋白纳米纤维膜。此外，在过滤过程中要特别注意纳米纤维网捕获的污染物的形态演变。已经发现，丝素蛋白的固有性质在改善过滤性能中起关键作用。得益于丰富的官能团，所得的丝素蛋白纤维膜显示出99.99％的高过滤效率，相对低的空气阻力仅为75 Pa，从而导致明显更高的品质因数。由于丝素蛋白的生物降解性，该膜在使用后是一次性的。我们相信，这里介绍的方法和结果不仅将为空气过滤提供一个新颖的视角，而且还将很好的服务于生产安全、清洁的空气过滤系统。

Published: 2018

Journal ：RSC Advances

Impact Factor：3.267

Paper link: https://pubs.rsc.org/lv/content/articlehtml/2018/ra/c7ra12879g