Nanofibrillated collagen fiber networks for enhanced air purification
J. Wang, Xinjie Huang, Peng Zhao, Dan Cao, Rui Li, Xinling Zhao, Yangrui Du, Kaijun Li, Chaojian Chen, Gongyan Liu
Abstract
Air filtration is essential for protecting human health, but commercial synthetic microfiber filters face challenges like complex manufacturing, poor biodegradability, limited biocidal properties, and reduced efficacy against volatile organic compounds and nanoscale particulates. Collagen fiber networks derived from animal hides offer a sustainable alternative due to their hierarchical structure and diverse surface functionalities. However, their thick fiber bundles (>5 μm) hinder filtration performance. Here we introduce a facile strategy combining physical processing and zwitterionic copolymer functionalization to disperse fibrils, followed by zirconium treatment for stabilization. The resulting filters, with finely dispersed nanofibrils (~120 nm) and increased exposure of functional groups, significantly enhance air purification, achieving 97% PM0.3 removal and nearly doubling formaldehyde elimination. These filters also exhibit robust antimicrobial properties, capturing and inactivating over 99% of bacterial aerosols. Life-cycle assessments demonstrate their biodegradability and cost-effectiveness, showcasing strong potential for large-scale production. This approach not only advances the use of nature-derived collagen fibers for air purification but also opens possibilities for broader applications, including nanomaterial separation and water purification. Air filtration is ubiquitous, though most commercial filters are not biodegradable, biocidal, or tolerant to volatile organic compounds. Here the authors report a facile strategy to engineer collagen fibers for sustainable, high-performance air purification.