Morphology, physical, and mechanical properties of potentially applicable coelectrospun polysulfone/chitosan-polyvinylalcohol fibrous membranes in water purification

Polysulfone (PSU) is a widely used polymer in water purification membranes. However, its hydrophobicity hinders its practical application. Herein, the wettability of PSU has been improved by producing a coelectrospun fibrous composite membrane using a hydrophilic component, chitosan-polyvinyl alcohol (CS-PVA). First, different proportions of PVA and CS solutions were mixed and electrospun to prepare CS-PVA blend fibers. Scanning electron microscope (SEM) observations revealed that CS-PVA blend fibers with maximum CS content can be obtained in 30:70 CS:PVA weight ratio. The optimum CS-PVA solution was subsequently used alongside PSU solution and were fed into two distinct syringes, which were then electrospun simultaneously at a constant voltage and distance of 15 kV and 15 cm, respectively. Different composite compositions of PSU/CS-PVA were achieved using different feeding rates for each solution. Based on SEM images, the prepared composite fibers were beadless. The ultimate strength of the composite mats decreased by increasing the amount of CS-PVA due to the significant difference in the fiber diameter of each component and the resulting stress concentration. However, the thermal stability of composite membranes remained almost the same as pure PSU fibers. Moreover, samples with higher CS-PVA content showed better wettability and higher water flux.