Functional Electrospun Membranes From Renewable Lignin for Clean Air Applications

This study explores the fabrication of sustainable lignin-based nanofibrous membranes with antibacterial properties, designed for high-efficiency air filtration applications. By leveraging lignin, a renewable biopolymer, in combination with triclosan and synthetic polymers such as poly(acrylonitrile) (PAN) and poly(vinylidene fluoride) (PVDF), electrospun fibres with enhanced filtration and antibacterial performance were developed. Morphological analysis revealed that the fibre diameters ranged from 0.05 to 0.209 μm, while pore sizes varied between 0.01 and 0.178 μm. These fine fibre structures and controlled pore sizes significantly enhanced filtration capabilities, achieving bacterial filtration efficiency (BFE) and particle filtration efficiency (PFE) of 99.9%. Furthermore, the membranes exhibited strong antibacterial activity, with antibacterial values exceeding A > 4 (ISO 20743), demonstrating their ability to inhibit bacterial growth effectively. The addition of lignin improved fibre uniformity and mechanical stability while enhancing adsorption capacity, making the membranes highly efficient in capturing ultrafine particles, including viruses and PM2.5. These findings underscore the potential of lignin-based membranes as eco-friendly, biodegradable and high-performance alternatives to conventional filtration materials, offering a sustainable solution to address environmental challenges associated with single-use polypropylene filters and microplastic generation.