Pervaporation studies of sodium alginate (SA)/dextrin blend membranes for separation of water and isopropanol mixture Original Research Article

The blend membranes of sodium alginate (SA)/dextrin were prepared by solution casting method followed by crosslinking with glutaraldehyde and used for the separation of water + isopropanol mixtures at 30 °C. Pervaporation (PV) separation characteristics were studied for the different water compositions (10–50 mass%) in the water + isopropanol feed mixtures through the prepared blend membranes. The crosslinked and un-crosslinked membranes were characterized by FTIR, DSC and surface morphology of membranes studied by SEM. The membrane performance was studied by calculating the flux and selectivity. Sorption studies were carried out to evaluate the extent of interaction and the degree of swelling of the membranes in pure liquids as well as in binary mixtures. The observed flux was higher for crosslinked SA/dextrin blend membranes, compared to plain crosslinked SA membrane; nevertheless, the selectivity was also higher for SA/dextrin (40:60 mass%), SA/dextrin (50:50 mass%) and SA/dextrin (60:40 mass%) blend membranes compared to the plain crosslinked SA membrane.