Tortuously structured polyvinyl chloride/polyurethane fibrous membranes for high-efficiency fine particulate filtration.

Two-tier composite filtration medium exhibiting excellent filtration performance to airborne particulate was prepared by a facile deposition of electrospun polyvinyl chloride (PVC)/polyurethane (PU) fibers on a conventional filter paper support. The tortuous structure and composition of resultant fibrous membranes can be finely controlled by regulating the precursor solution composition. By employing the PU incorporation, the pristine PVC fibrous membranes were endowed with robust tensile strength approaching to 9.9 MPa. The plausible correlation between resultant blended fibrous structure and mechanical property of relevant membranes was discussed, and a three-step break mechanism upon the external stress was proposed. Additionally, quantitative pore size and porosity distribution analysis using the capillary flow porometry method has confirmed the tortuous structure of PVC/PU fibrous membranes. Furthermore, the as-prepared membranes with high abrasion resistance (134 cycles) and comparable air permeability (154.1mm/s) showed fascinating filtration efficiency (99.5%) and low pressure drop (144 Pa) performance for 300-500 nm sodium chloride aerosol particles, suggesting their use as a promising medium for variety of potential applications in air filtration.