Indoor air quality (IAQ) has assumed new significance given the extensive amount of time spent indoor due to the coronavirus pandemic and particulate matter (PM) pollution. Accordingly, the development of window air filters to effectively intercept PM from outdoor air under natural ventilation conditions is an important research topic. However, most existing filters inevitably suffer from the compromise among filtration capability, transparency, and air permeability. In this study, we fabricate a high-performance transparent air filter to improve IAQ via natural ventilation. polyvinylidene fluoride (PVDF) superfine nanofibers of size 20–35 nm are prepared using extremely dilute solution electrospinning; a multi-scale nanofiber structure is then designed. By adjusting the ratio of PVDF superfine nanofibers (SNs) to PVDF coarse fibers (CNs), we balance the structure–performance relationship. Benefiting from the multiscale structural features that include a small pore size (0.72 μm) and high porosity (92.22%), the resulting filters exhibit excellent performance including high interception efficiency (99.92%) for PM_0.3, low air resistance (69 Pa), high transparency (∼80%) and stable filtration after 100 h of UV irradiation. This work describes a new strategy for the fabrication of nanofibers with true-nanoscale diameters and the design of high-performance air filters.

由于冠状病毒大流行和颗粒物 (PM) 污染，室内空气质量 (IAQ) 具有新的重要性。因此，开发窗式空气过滤器以在自然通风条件下有效拦截室外空气中的 PM 是一个重要的研究课题。然而，大多数现有过滤器不可避免地受到过滤能力、透明度和透气性之间的妥协。在这项研究中，我们制造了一种高性能透明空气过滤器，通过自然通风改善室内空气质量。使用极稀溶液静电纺丝制备尺寸为 20-35 nm 的聚偏二氟乙烯 (PVDF) 超细纳米纤维；然后设计了多尺度纳米纤维结构。通过调整 PVDF 超细纳米纤维 (SNs) 与 PVDF 粗纤维 (CNs) 的比例，我们平衡了结构-绩效关系。受益于包括小孔径 (0.72 μm) 和高孔隙率 (92.22%) 的多尺度结构特征，所得过滤器表现出优异的性能，包括对 PM 的高拦截效率 (99.92%)_0.3、低空气阻力 (69 Pa)、高透明度 (~80%) 和紫外线照射 100 小时后的稳定过滤。这项工作描述了一种制造具有真正纳米级直径的纳米纤维和设计高性能空气过滤器的新策略。