Short cellulose acetate nanofibers: A novel and scalable coating for enhancing nanoparticles filtration efficiency of filter media

Author(s)

Chagas, Paulo A. M. ; Lima, Felipe A. ; Yamanaka, Vitor ; Medeiros, Gabriela B. ; Guerra, Vadila G. ; Oliveira, Wanderley P. ; Aguiar, Monica L.

• Document type: Journal article
• Source: Separation and Purification Technology; v. 358, p. 14-pg., 2025-06-07.

Abstract

This study introduces a novel and scalable approach to significantly enhance the filtration efficiency of automotive cabin air filters using short cellulose acetate nanofibers applied via a spray coating method. The short nanofibers, produced through the mechanical fragmentation of electrospun mats, enable uniform dispersion and application onto microfibrous filter media, addressing a key limitation in nanofiber technology. This innovative process enhances the capture of ultrafine particles (7.4 to 250 nm), which are critical for improving air quality in confined environments such as vehicle cabins. The filters, coated with nanofiber weights ranging from 1 to 13 mg, showed a prominent improvement in filtration efficiency, achieving quality factors (Qf) from 0.01 to 0.0221 Pa-1, outperforming both uncoated filters (0.0025 Pa-1) and commercial HEPA filters (0.0212 Pa-1). Filtration efficiency increased from 18 % to 99.8 %, with corresponding pressure drops between 44.5 and 620 Pa. Remarkably, a filter with 9 mg of nanofibers achieved a superior quality factor of 0.0221 Pa-1, effectively optimizing both efficiency and pressure drop while outperforming HEPA filters. This method addresses the common challenge in conventional filters of balancing filtration efficiency with pressure drop. The scalable spray coating process, combined with the advantages of electrospinning, offers a practical, industrially viable solution to improve air filtration in automotive HVAC systems and other environments requiring high filtration efficiency and low-pressure drop. (AU)

• FAPESP's process: 23/05407-3 - Production process of short nanofibers, applications and uses
• Grantee: Paulo Augusto Marques Chagas
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE