Pervaporation dehydration of acetonitrile with TiO 2 -enhanced crosslinked sodium alginate membranes

Acetonitrile is an important solvent in many analytical, chemical, and pharmaceutical applications. Its dehydration is difficult because it forms an azeotrope with water. In this work, sodium alginate (NaAlg) mixed matrix membranes crosslinked with sulfosuccinic acid and loaded with 0–8 wt% TiO2 nanoparticles were prepared by solution casting and used for acetonitrile/water separation by pervaporation. The membrane structure and swelling were studied, and pervaporation tests were done at different feed water contents (10–30 wt% at 23°C) and at different temperatures (23–50°C) for the membrane with 8 wt% TiO2. A higher water content in the feed increased the total flux but decreased the separation factor, while adding TiO2 nanoparticles reduced membrane swelling and clearly improved selectivity compared to pure NaAlg. The NaAlg–8 wt% TiO2 membrane showed the best performance, with a total flux of about 1.37 kg/m2·h and a separation factor of about 162 at 23°C and 10 wt% water in the feed, and its performance improved further at 50°C. These findings show that TiO2filled crosslinked NaAlg mixed matrix membranes are promising materials for energyefficient dehydration of acetonitrile by pervaporation.