A Nanoprotein-Functionalized Hierarchical Composite Air Filter

Building nanostructured active materials and rational porous structures in air filters will be significant in realizing high filtration efficiency and low normalized pressure drop. The construction of nanofabrics by electrospinning can lead to large active surface areas, but it has been challenging to control the porous structures to reduce the normalized pressure drop, in particular for thick fabrics. To address this issue, here, we report a protein-functionalized composite air filter with hierarchical structures. This composite is made of bacterial nanocellulose coated by protein nanoparticles and microcellulose fibers from wood pulp. The protein-functionalized nanocellulose can not only help expose the functional groups of protein for trapping pollutants but also act as a binder to reinforce the composite fabrics. At the same time, the long microcellulose fibers form large pores, reducing normalized pressure drop and improving mechanical properties. By adjusting the component ratios, we demonstrate a high-performance protein/nanocellulose/microcellulose composite air filter with high filtration efficiency of above 99.5% for PM1-2.5 but extremely low normalized pressure drop of 0.194 kPa/g, which is only about 1% of that for protein nanofabrics constructed by electrospinning. This study brings about a cost-effective strategy based on protein-functionalized hierarchical composite fabrics for fabrication of an advanced, green, sustainable air filter.

在空气过滤器中构建纳米结构的活性材料和合理的多孔结构对于实现高过滤效率和低归一化压降将具有重要意义。通过静电纺丝构造纳米织物可以导致较大的有效表面积，但是控制多孔结构以减小标准化的压降（特别是对于厚织物而言）具有挑战性。为了解决这个问题，在这里，我们报告一种具有层次结构的蛋白质功能化复合空气过滤器。这种复合材料由被蛋白质纳米颗粒和木浆中的微纤维素纤维包裹的细菌纳米纤维素制成。蛋白质功能化的纳米纤维素不仅可以帮助暴露蛋白质的官能团以捕获污染物，而且还可以充当粘合剂来增强复合面料。同时，长的微纤维素纤维会形成大孔，减少归一化的压降并改善机械性能。通过调整组分比率，我们证明了一种高性能的蛋白质/纳米纤维素/微纤维素复合空气过滤器，对于PM1-2.5的过滤效率高达99.5％，但归一化压降仅为0.194 kPa / g，非常低，仅为约1％其中的一种是通过静电纺丝构建的蛋白质纳米纤维。这项研究提出了一种基于蛋白质功能化的分层复合面料的经济高效的策略，用于制造先进的，绿色环保的，可持续的空气过滤器。

Published: 2018

Journal ：ACS Sustainable Chemistry & Engineering

Impact Factor：7.929

Paper link: https://pubs.acs.org/doi/abs/10.1021/acssuschemeng.8b01827