Hydrophilic–hydrophobic polymer based blend membrane for separation of water–isopropanol mixtures by pervaporation

Pervaporation (PV) separation of water–isopropanol has been attempted using the blend membranes of poly (vinyl alcohol) (PVA) with poly (styrene-co-acrylonitrile) (PSA), and poly (vinyl alcohol) (PVA) with poly (styrene-co-methyl methacrylate) (PSM). Here, we described the fabrication of Hydrophilic–hydrophobic blend polymer membranes of PVA/PSM and PVA/PSA by solution casting method and cross-linked with glutaraldehyde (GA) in the presence of aqueous hydrochloric acid (HCl). These membranes were analyzed by Fourier transform (FTIR) infrared analysis, Field emission scanning electron microscopy (FESEM) analysis, Differential scanning calorimetry (DSC) and Thermo gravimetric analysis (TGA). Pervaporation experiments were conducted at 30 °C for 10, 12.5, and 15 wt.% of aqueous isopropanol feed mixtures and membrane performance was evaluated by calculating flux, selectivity and pervaporation separation index (PSI). Highest selectivity of 281 with flux of 0.076 kg/m2h has been observed PVA/PSM blend membrane when compared to pristine PVA membrane to dehydrate 12.5 wt.% water in feed mixture. Flux values were decreased from 0.112 to 0.076 kg/m2h to dehydrate 12.5 wt.% water in feed mixture for PVA/PSM blend membrane and plain PVA membrane. The developed blend membrane selectivity was improved dramatically whereas flux was decreased compared to the plain PVA membrane.