Electrospun PU/P(AMPS-GO) nanofibrous membrane with dual-mode hydrophobic–hydrophilic properties for protective clothing applications

Bi-functional nanofibrous membrane composed of polyurethane in one face and poly(2-acryloylamido-2-methylpropanesulfonic acid)-graphene oxide (PAMPS-GO) in another face has been fabricated using two opposite-nozzle electrospinning set-up. The effect of graphene oxide addition on morphology of PAMPS nanofibers and performance of membrane were investigated. Besides structure of graphene oxide layers, electrospun nanofibers were studied using TEM, X-ray, FTIR, and FE-SEM methods. To evaluate the nanofibrous membrane performance, their tensile strength, water vapor permeability, and contact angle were measured. An average diameter of 500 nm and 83 nm were obtained for PU and PAMPS nanofibers, respectively, through the optimized electrospinning process. Results show that PAMPS nanofiber diameters together with pore sizes of its mat decrease by increasing the graphene oxide content. Also, the dimensional stability of electrospun fibers against water vapor was strengthened in the presence of graphene oxide nanosheets. An improvement in tensile strength of PAMPS nanofibers was observed by the addition of graphene oxide up to 0.2 wt.%, while more addition caused a negative change. Studying water vapor permeability of PAMPS nanofibers showed that increasing the graphene oxide content, the water vapor permeability increases. However, it decreases by increasing the surface density of nanofibers. From a hydrophobic–hydrophilic perspective, an excellent dual-mode behavior on two opposite faces was observed that is already proper for water proof-breathable protective clothing and wound dressing applications.