He Xinjian, Wang Cunmin, Hao Yaxin, Li Jiaqi, Zhu Guiying, Jiang Liang, Shao Jiang, Zhang Mingming, Li Xiao-Peng, Li Heguo, Xu Huan
School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China.
Jiangsu Engineering Research Center of Dust Control and Occupational Protection, Xuzhou 221008, China.
ACS Appl Mater Interfaces. 2024 Oct 9;16(40):54873-54884. doi: 10.1021/acsami.4c12064. Epub 2024 Sep 30.
The wide use of conventional polymeric air filters is causing a dramatically increasing accumulation of plastic and microplastic pollution. The development of poly(lactic acid) (PLA) fibrous membranes for efficient air purification is of important significance but frequently challenged by the rapid decay of filtration performance due to the intrinsically poor electret properties of PLA. Here, we propose an electroactivity promotion methodology, involving the one-step synthesis and homogeneous incorporation of high-dielectric ZIF-8 nanosheets (ZIFNSs), to facilitate interfacial polarization and fiber refinement during electrospinning of PLA nanofibers. The preparative electrospun PLA/ZIFNS meta-membranes exhibited an unusual combination of significantly reduced nanofiber diameter (∼462 nm), enhanced surface potential (approaching 10 kV), and increased surface activity and facilitated the formation of electroactive phases. With well-controlled morphological features, the highly electroactive PLA/ZIFNS meta-membranes exhibited exceptional filtration efficiencies for PM and PM (99.2 and 96.0%, respectively) even at the highest airflow rate of 85 L/min, in clear contrast to that of its pure PLA counterpart (only 79.3 and 74.6%). Arising from the increased electroactivity and active contact sites, remarkable triboelectric performance and self-charging mechanisms were demonstrated for the PLA/ZIFNS meta-membranes, contributing to long-term efficient PM filtration (97.5% for over 360 min). Moreover, as triggered by physiological activities like respiration and speaking, the electroactive PLA/ZIFNS meta-membranes enabled real-time monitoring with high sensitivity and specificity. The proposed strategy affords significant promotion of electroactivity and triboelectric performance for PLA nanofibers, which may motivate the development of ecofriendly protective membranes for respiratory healthcare and real-time monitoring.
传统聚合物空气过滤器的广泛使用正导致塑料和微塑料污染的急剧增加。开发用于高效空气净化的聚乳酸（PLA）纤维膜具有重要意义，但由于PLA固有的驻极体性能较差，其过滤性能的快速衰减常常成为挑战。在此，我们提出一种电活性促进方法，即一步合成并均匀掺入高介电常数的ZIF-8纳米片（ZIFNSs），以促进PLA纳米纤维静电纺丝过程中的界面极化和纤维细化。制备的静电纺PLA/ZIFNS元膜呈现出显著减小的纳米纤维直径（约462 nm）、增强的表面电位（接近10 kV）以及增加的表面活性等不同寻常的组合，并促进了电活性相的形成。凭借良好控制的形态特征，即使在85 L/min的最高气流速率下，高电活性的PLA/ZIFNS元膜对PM和PM也表现出卓越的过滤效率（分别为99.2%和96.0%），这与其纯PLA对应物形成鲜明对比（仅为79.3%和74.6%）。由于电活性和活性接触位点的增加，PLA/ZIFNS元膜展现出显著的摩擦电性能和自充电机制，有助于长期高效的PM过滤（超过360分钟内保持97.5%）。此外，受呼吸和说话等生理活动触发，电活性PLA/ZIFNS元膜能够实现高灵敏度和特异性的实时监测。所提出的策略显著提升了PLA纳米纤维的电活性和摩擦电性能，这可能会推动用于呼吸保健和实时监测的环保防护膜的发展。
