Development of novel mordenite-filled chitosan–poly(acrylic acid) polyelectrolyte complex membranes for pervaporation dehydration of ethylene glycol aqueous solution

Mordenite-filled chitosan–poly(acrylic acid) polyelectrolyte complex membranes (PECM) were prepared by incorporating mordenite into CS and PAAc blending solution for pervaporation separation of ethylene glycol (EG) aqueous solution. The membranes were characterized by Fourier transform-infrared (FT-IR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and universal testing machine, respectively. The effects of mordenite content on sorption, diffusion and pervaporation performance of the membranes were evaluated. The permeation flux decreased while the separation factor first increased and then decreased with increasing the mordenite content. The M04-PECM60/40 containing 4 wt% mordenite showed the highest separation factor of 258 with a permeation flux of 165 g/m2 h for 80 wt% EG in feed at 70 °C. The diffusion coefficients of water and EG for the mordenite-filled membranes were estimated, which revealed that the membranes were highly water selective. The effects of EG concentration in the feed, operating temperature and feed flow rate on pervaporation performance of the membrane were systematically investigated. The Arrhenius activation energy was found to decrease for water but obviously increase for EG after incorporation of mordenite, indicating that water molecules required much less energy than EG molecules to cross the membrane.