Development of zeolite-A incorporated PVA/CS nanofibrous composite membranes using the electrospinning technique for pervaporation dehydration of water/tert-butanol

Abstract

Using the electrospinning technique, composite nanofibrous membranes were developed on a dense PVA layer from a solution of poly(vinyl alcohol) (PVA)/chitosan (CS)/zeolite-A. The resulting composite nanofibrous membranes were crosslinked using the vapour crosslinking technique. The physicochemical properties of the composite nanofibrous membranes were studied using various techniques, such as FTIR, WXRD, DSC, TGA, SEM and UTM. The diameter of the nanofibers was increased from 136 to 239 nm by increasing the content of zeolite-A in the PVA/CS solution. The effect of zeolite-A in the nanofibrous composite membranes was systematically studied for pervaporation dehydration of water/tert-butanol. Among the various membranes developed, the membrane containing 0.9 wt% of zeolite exhibited the highest separation factor of 1324 with a flux of 13.67 × 10⁻² kg m⁻² h at 30 °C for 10 mass% of water in the feed. For all the membranes, the values of total flux were found to be almost close to the values of water flux, suggesting that the developed composite nanofibrous membranes are highly selective towards water. The efficiency of the membranes was discussed based on the calculated Arrhenius activation energy values. All of the composite nanofibrous membranes demonstrated positive ΔH_s values, signifying that Henry's mode of sorption was predominant. Based on the excellent separation factor and permeate flux, it is concluded that the developed composite nanofibrous membranes could be the most promising candidates for the industrial separation of water/tert-butanol.