Air pollution caused by fine particulate matter (PM_0.3) has drawn increasing attention as an overwhelming threat to public health. Electret treatment is commonly used to improve the filtration performance of commercial fibrous filter materials by enhancing the electrostatic adsorption effect, but it is greatly affected by environmental factors (especially humidity). Moreover, filter materials are generally non-degradable and non-recyclable, causing serious environmental pollution. Herein, a strategy to manufacture fully degradable polylactic acid (PLA) filtration composites based on porous PLA nanofibers prepared by electrospinning was investigated in this study. Porous, bead-on-string and conventional PLA nanofibers could be obtained by adjusting spinning condition parameters. The porous PLA nanofibers exhibited 9.8 times greater specific surface area (24.01 m² g⁻¹) and 18 times more cumulative pore volume (0.108 cm³ g⁻¹) than conventional PLA nanofibers. More importantly, fibrous filtration composites based on porous PLA nanofibers possessed a high PM_0.3 filtration efficiency (99.9989%), low pressure drop (90.35 Pa) and high air permeability (72.4 Pa⁻¹) at an air flow rate of 32 L min⁻¹ without electret treatment. The fibrous filtration composites based on conventional or bead-on-string PLA nanofibers also exhibited excellent filtration performance (>99.99%), but the associated high pressure drop and low air permeability limited their application.

中文翻译：

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多孔聚乳酸纳米纤维的制备及其在非驻极高效过滤复合材料中的应用

由细颗粒物 (PM _0.3 ) 引起的空气污染作为对公众健康的巨大威胁而受到越来越多的关注。驻极体处理常用于通过增强静电吸附效果来提高商业纤维过滤材料的过滤性能，但其受环境因素（尤其是湿度）影响较大。而且过滤材料一般不可降解、不可回收，造成严重的环境污染。本研究研究了一种基于静电纺丝制备的多孔 PLA 纳米纤维制造完全可降解聚乳酸 (PLA) 过滤复合材料的策略。通过调整纺丝条件参数可以获得多孔、串珠和常规PLA纳米纤维。多孔PLA纳米纤维比传统PLA纳米纤维表现出9.8倍的比表面积（24.01 m ² g ^-1）和18倍的累积孔体积（0.108 cm ³ g ^-1）。更重要的是，基于多孔PLA纳米纤维的纤维过滤复合材料在32 L min的空气流量下具有高PM _0.3过滤效率（99.9989%）、低压降（90.35 Pa）和高透气率（72.4 Pa ^{-1 ） - 1.}未经驻极处理。基于传统或串珠PLA纳米纤维的纤维过滤复合材料也表现出优异的过滤性能（>99.99%），但相关的高压降和低透气性限制了其应用。