Heat rolling as a post-treatment technique to enhance the integrity of electrospun nanofibrous membranes

Abstract

Membranes fabricated based on electrospinning inherently allow for high porosity and large effective surface area but are physically weak and unstable. In this study, heat rolling was performed with different speed and various temperatures to improve the mechanical properties of electrospun nanofibrous membranes (ENMs). Although nanofibers did not fuse with each other tightly like those seen after other heat-based post-treatments, the ENMs after heat rolling were suitable to be used as filters for water treatment because of enhanced tensile strength and integrity. While the tensile strength of ENM without heat rolling was 0.95 MPa, the mechanical strength of ENMs increased from 1.57 MPa to 2.21 MPa depending on temperature at a fast heat rolling of 4.3 cm/s. As for a slow heat rolling of 1.25 cm/s, the mechanical properties were further improved and showed a value of 2.51 MPa at the temperature of 150 °C. Moreover, the foulants on the surface of the ENMs were detached by physical cleaning compared to commercial membranes based on the phase-inversion method.