Efficient dye removal from aqueous solution by high-performance electrospun nanofibrous membranes through incorporation of SiO2 nanoparticles

In this study, novel chitosan/poly(vinyl alcohol) (PVA)/SiO2 nanocomposite ENMs were prepared to improve the mechanical strength and permeation properties of ENMs. The effect of various concentrations of SiO2 in the spinning solution (0, 0.5, 1.0 and 2.0 wt %) on the morphology, fiber diameter, porosity, thermomechanical properties, and permeability of the synthesized membranes was investigated. The prepared affinity membranes were utilized for the removal of dye from colored wastewater. Incorporating SiO2, as a reinforcing agent, was found to increase the compaction resistance of the nanocomposite ENMs. With the addition of 0.5 wt % of SiO2, the Young's modulus of the prepared membranes almost doubled from 0.74 MPa for chitosan/PVA ENM to 1.69 for nanocomposite ENM. The major finding was that with the incorporation of 1.0 wt % SiO2, a marked increase in both water permeability and dye rejection is attained. The optimized nanocomposite membrane provided 98% Direct Red 23 rejection and 1711 l/m2h flux under 0.4 bar transmembrane pressure. As a result, this study provides valuable insights into the preparation of high-performance and robust nanocomposite ENMs for the wastewater treatment.