Niu Zhuolun, Xiao Can, Mo Jinhan, Zhang Li, Chen Chun
Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin N.T. 999077, Hong Kong SAR, China.
Department of Building Science, Tsinghua University, Beijing 100084, China.
ACS Appl Mater Interfaces. 2022 Jun 3. doi: 10.1021/acsami.2c06808.
Integrating metal-organic frameworks (MOFs) into electrospun nanofiber filters has become an effective method for improving particle filtration efficiency. This study hypothesized that there is an optimal amount of MOFs that can be integrated into electrospun nanofiber filters to achieve the maximum particle removal efficiency while minimizing the corresponding MOF synthesis time. To test the hypothesis, this study systematically explored the influence of the time-dependent in situ growing process of zeolitic imidazolate framework-67 (ZIF-67), a typical type of MOFs, on the filtration performance of polyacrylonitrile (PAN) electrospun nanofibers. The results show that the surface morphology and chemical composition of the PAN/ZIF-67 hybrid nanofiber filters gradually changed with the reaction time. For PAN/ZIF-67 hybrid nanofiber filters with relatively low initial PM filtration efficiency, a reaction time of only 5 min was sufficient for the synthesis of the amount of ZIF-67 that maximized the PM filtration efficiency. However, for thick filters with high original PM filtration efficiency (>90%), the integration of ZIF-67 was not necessary, because the efficiency enhancement would not be significant. In addition, the enhancement of filtration efficiency for ultrafine particles was positively correlated with the amount of incorporated ZIF-67. In summary, this study shortened the synthesis time of the in situ incorporation of MOFs into electrospun nanofiber filters from more than 10 h (reported in the literature) to only 5 min.
将金属有机框架材料（MOFs）整合到电纺纳米纤维过滤器中已成为提高颗粒过滤效率的有效方法。本研究假设，存在一个最佳的MOFs用量，可以整合到电纺纳米纤维过滤器中，以实现最大的颗粒去除效率，同时将相应的MOF合成时间降至最低。为了验证这一假设，本研究系统地探讨了典型的MOFs类型——沸石咪唑酯骨架-67（ZIF-67）的时间依赖性原位生长过程对聚丙烯腈（PAN）电纺纳米纤维过滤性能的影响。结果表明，PAN/ZIF-67混合纳米纤维过滤器的表面形态和化学成分随反应时间逐渐变化。对于初始PM过滤效率相对较低的PAN/ZIF-67混合纳米纤维过滤器，仅5分钟的反应时间就足以合成使PM过滤效率最大化的ZIF-67量。然而，对于原始PM过滤效率高（>90%）的厚过滤器，ZIF-67的整合没有必要，因为效率提升不显著。此外，超细颗粒过滤效率的提高与掺入的ZIF-67量呈正相关。总之，本研究将MOFs原位掺入电纺纳米纤维过滤器的合成时间从文献报道的10多个小时缩短至仅5分钟。
