Enhanced glycerol dehydration of pervaporation cross‐linkedPVAmembranes modified byVUV/UV‐Ctreatments

Abstract

The high glycerol miscibility in water needs more efficient processes to decrease the cost of dehydration. Water stable poly(vinyl alcohol) based membranes cross‐linked with 15% w/w of maleic acid were used for dehydrating glycerol‐water mixtures using pervaporation (PV). The membranes were characterized using water contact angle, profilometry, Fourier transformed infrared spectroscopy‐attenuated total reflectance, x‐ray photoelectron spectroscopy, water stability, swelling tests, and PV. Membranes were treated using dry methods with vacuum ultraviolet (VUV; 162 nm) or ultraviolet (UV)‐C (254 nm) radiation and exposed to O2 or acrylic acid vapors, respectively. The VUV and UV‐C treatments improve PV performances, increasing the water separation selectivity more than 4 and 8.5 times, respectively. UV‐C treatments exhibit a water flux (kg m−2 h−1), selectivity and PSI (kg m−2 h−1) of 0.3, 250, and 87.4 respectively. Highly hydrophilic functional groups grafted onto the surface of the membranes after irradiation favor the selective transfer of water through the membrane. Overall, the VUV or UV‐C membrane treatments show great PV prospect in glycerol dehydration.