The present research aimed to investigate the influence of layer arrangement and composition ratio on tensile and transport properties in bi-constituent electrospun nanofibrous membranes composed of polyurethane nanofibers with a hydrophobic nature and poly(2-acrylamido-2-methylpropanesulfonic acid) with a hydrophilic nature. Different hybrid electrospun nanofibrous membranes were produced based on different layer arrangement and composition ratios. To evaluate the membrane performance, their tensile strength, wind, and waterproof performance were measured. By adding 50% poly(2-acrylamido-2-methylpropanesulfonic acid) to polyurethane, the pore size of the hybrid electrospun nanofibrous membranes decreased by 47.64%. As a result, compared with pristine polyurethane membranes, hybrid electrospun nanofibrous membranes showed a good (9.6 mm s−1) windproof performance. Adding poly(2-acrylamido-2-methylpropanesulfonic acid) nanofibers to the polyurethane resulted in a decrease in mechanical properties and waterproof performance. The results show that the volume fraction of the poly(2-acrylamido-2-methylpropanesulfonic acid) and the electrospinning scenarios have a great influence on the mechanical properties of the samples. The results also show that the mechanical properties of hybrid electrospun nanofibrous membranes can be predicted based on the geometrical properties of each component. Computational fluid dynamics were used to simulate air flow through a virtual medium and the results of simulation were compared with the experimental measurement and predicted permeability; then, the best models for predicting air permeability were determined. In addition, based on different types of use, duration of use, and relative humidity level, a bi-functional membrane can be obtained by regulating layer arrangement and composition ratios to suit various applications, for example, in medical disposable clothing, wound dressing, filtering industries, and protective clothing.

This study aimed to examine the fabrication of bi-constituent nanofibrous membranes and investigation of their moisture management behavior in various environmental conditions. In doing so, polyurethane with a hydrophobic nature and superior mechanical behavior and poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) with a hydrophilic nature were utilized. Different hybrid electrospun nanofibrous membranes were aligned based on different layer arrangements and composition ratios. Then, the impacts of the solid fraction of polymers, sequence of stacking, and environmental conditions on water vapor permeability, contact angle, and acidic water permeation were measured and discussed. Tracing the water vapor permeability behavior in samples was carried out through measuring the amount of permeation hourly and proposing some regression models. Bi-modal nanofibrous membranes were successfully fabricated using PAMPS and polyurethane with an average fiber diameter of 543.5 and 216.7 nm, respectively. As the volume fraction of PAMPS increased, the porosities of the samples remained unchanged, the number of pores increased, and the pore size decreased (the average pore diameter was 299.97 nm for the PAMPS sample and 492.35 nm for the polyurethane sample). Despite the better water vapor permeability of the polyurethane membranes than that of the PAMPS membranes, in the first 12 h of the water vapor permeability test, the trend was completely reverse. The results also revealed that in the relative humidity of 55%, the polyurethane layer had the highest water vapor permeability among all samples. The results of the acidic water permeation and contact angle tests showed that the hybrid electrospun nanofibrous membranes exhibit better wicking and wetting properties.