Elastic acrylonitrile-butadiene copolymer fibers were electrospun to fabricate fiber mats of five different basis weights: 10, 20, 30, 45, and 60 g/m(2). The fiber mats were investigated for properties of pore diameter and permeability. As the basis weight increased, bubble point and mean flow pore diameters as well as the permeability/mat-thickness values decreased. The fiber mats were tested as filter media for capture of NaCl nanoparticles from aerosol flow. Due to the elastic nature of the fibers, the mats were tested in stretched and non-stretched, conditions to evaluate changes in filter performance. The pressure drop and penetration of the filter media were calculated using correlations from literature and by assuming idealized properties of constant mat thickness or constant mat volume when the mat is stretched. Experimentally, the fiber mats of higher basis weights yielded higher pressure drops and lower penetrations compared to lower basis weight mats. The stretched fiber mats showed decreased pressure drops and increased particle penetrations compared to the non-stretched mats due to the enlargement of pores within the mats. The FI values were about the same between stretched and non-stretched mats of same starting basis weights. (C) 2017 Elsevier B.V. All rights reserved.