Zhou Zhiqiang, You Tianle, Pan Zhengyuan, Wang Di, Wang Hao, Wang Lingyun, Xu Guilong, Liang Yun, Hu Jian, Tang Min
School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510641, China.
Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.
Adv Mater. 2024 Jun;36(24):e2311129. doi: 10.1002/adma.202311129. Epub 2024 Apr 10.
Air pollution threats to human health have increased awareness of the role of filter units in air cleaning applications. As an ideal energy-saving strategy for air filters, the slip effect on nanofiber surfaces can potentially overcome the trade-off between filtration efficiency and pressure drop. However, the potential of the slip effect in nanofibrous structures is significantly limited by the tight nanofiber stacks. In this study, trichome-like biomimetic (TLB) air filters with 3D-templated silicone nanofilaments (average diameter: ≈74 nm) are prepared based on an in situ chemical vapor deposition (CVD) method inspired by plant purification. Theoretical modeling and experimental results indicate that TLB air filters make significant use of the slip effect to overcome the efficiency-resistance tradeoff. The selectable filter class (up to U15, ≈99.9995%) allows TLB air filters to meet various requirements, and their integral filtration performance surpasses that of most commodity air filters, including melt-blown cloth, ePTFE membranes, electrospun mats, and glass fiber paper. The proposed strategy directly transforms commercial filter media and filters into TLB air filters using a bottom-up, one-step approach. As a proof-of-concept, reusable N95 respirators and air purifiers equipped with TLB air filters are fabricated, overcoming the limitations of existing filter designs and fabrication methods.
空气污染对人类健康的威胁提高了人们对过滤装置在空气净化应用中作用的认识。作为空气过滤器的一种理想节能策略，纳米纤维表面的滑移效应有可能克服过滤效率与压降之间的权衡。然而，紧密的纳米纤维堆叠显著限制了纳米纤维结构中滑移效应的潜力。在本研究中，基于受植物净化启发的原位化学气相沉积（CVD）方法，制备了具有三维模板化硅纳米丝（平均直径：约74纳米）的毛状体仿生（TLB）空气过滤器。理论建模和实验结果表明，TLB空气过滤器充分利用了滑移效应来克服效率-阻力权衡。可选择的过滤等级（最高可达U15，约99.9995%）使TLB空气过滤器能够满足各种要求，并且它们的整体过滤性能超过了大多数商用空气过滤器，包括熔喷布、ePTFE膜、电纺垫和玻璃纤维纸。所提出的策略采用自下而上的一步法将商用过滤介质和过滤器直接转化为TLB空气过滤器。作为概念验证，制造了配备TLB空气过滤器的可重复使用的N95口罩和空气净化器，克服了现有过滤器设计和制造方法的局限性。
