Polylactide/polyhydroxybutyrate (PLA/PHB) nanofibers were prepared by electrospinning and functionalized with different amounts of ammonium-based ionic liquid (IL) belonging to quaternary ammonium compounds (QACs) to obtain a fibrous mat with antimicrobial properties for aerosol particle filtration. The filtration performance of these biopolymer nanofiber mats was evaluated by measuring the filter penetration of sodium chloride (NaCl) aerosol particles ranging from 20 to 600 nm. These filtration test results showed that the quality factors remain unvaried with the addition of IL and depend mostly on the electrospinning time. The "multi-layering" method was adopted to fabricate highly efficient nanofiber filters with a greatly reduced pressure drop. A quantitative analysis of the antimicrobial activity is also presented. The results show that renewable materials, such as PLA blended with PHB, can be considered for biodegradable filters, in line with the future trend to develop eco-sustainable products. Adding QAC salt to the biopolymer blend combines these qualities with an innovative bactericidal nanomaterial. (C) 2015 Elsevier B.V. All rights reserved.