School of Materials Science and Physics, China University of Mining and Technology, Xuzhou 221116, China.
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.
Int J Biol Macromol. 2024 Mar;260(Pt 2):129566. doi: 10.1016/j.ijbiomac.2024.129566. Epub 2024 Jan 20.
Despite great potential in fabrication of biodegradable protective membranes by electrospinning of poly(lactic acid) (PLA) nanofibers, it is still thwarted by smooth surfaces and poor electroactivity that challenge the promotion of electret properties and long-term air filtration performance. Here, a microwave-assisted synthetic method was used to customize dielectric TiO nanocrystals of ultrasmall and uniform dimensions (∼30 nm), which were homogeneously embedded at beaded PLA nanofibers (PLA@TiO, diameter of around 280 nm) by the combined "electrospinning-electrospray" approach. With small amounts of TiO (2, 4 and 6 wt%), the nanopatterned PLA@TiO nanofibrous membranes (NFMs) were characterized by largely increased dielectric constants (nearly 1.9), surface potential (up to 1.63 kV) and triboelectric properties (output voltage of 12.2 V). Arising from the improved electroactivity and self-charging mechanisms, the nanopatterned PLA@TiO NFMs exhibited remarkable PM filtration properties (97.9 %, 254.6 Pa) even at the highest airflow rate of 85 L/min, surpassing those of pure PLA membranes (86.2 %, 483.7 Pa). This was moreover accompanied by inhibition rates of 100 % against both E. coli and S. aureus, as well as excellent UV-blocking properties (UPF as high as 3.8, T of 50.9 % and T of 20.1 %). The breathable and electroactive nanopatterned PLA NFMs permit promising applications in multifunctional protective membranes toward excellent UV shielding and high-efficiency removal of both PMs and pathogens.
尽管通过静电纺丝聚乳酸（PLA）纳米纤维制造可生物降解的保护膜具有巨大的潜力，但由于光滑的表面和较差的电活性，仍然阻碍了驻极体性能和长期空气过滤性能的提升。在这里，采用微波辅助合成方法定制了具有超小和均匀尺寸（约 30nm）的介电 TiO 纳米晶，通过“静电纺丝-电喷”的组合方法均匀地嵌入到珠状 PLA 纳米纤维（PLA@TiO，直径约 280nm）中。通过添加少量的 TiO（2、4 和 6wt%），纳米图案化 PLA@TiO 纳米纤维膜（NFMs）的介电常数（接近 1.9）、表面电位（高达 1.63kV）和摩擦起电性能（输出电压 12.2V）均有显著提高。由于电活性和自充电机制得到改善，纳米图案化 PLA@TiO NFMs 表现出出色的 PM 过滤性能（97.9%，254.6Pa），即使在最高气流速率 85L/min 下，也超过了纯 PLA 膜（86.2%，483.7Pa）。此外，纳米图案化 PLA NFMs 对大肠杆菌和金黄色葡萄球菌的抑制率均达到 100%，并且具有优异的紫外线阻挡性能（UPF 高达 3.8，T 值为 50.9%，T 值为 20.1%）。这种透气且具有电活性的纳米图案化 PLA NFMs 有望应用于多功能防护膜，以实现优异的紫外线屏蔽和高效去除 PM 和病原体的功能。
