Pervaporation dehydration of isopropanol using homogeneous polyelectrolyte complex membranes of poly(diallyldimethylammonium chloride)/sodium carboxymethyl cellulose

Polyelectrolyte complexes (PECs) between poly(diallyldimethylammonium chloride) (PDDA) and sodium carboxymethyl cellulose (CMCNa) with four ionic complexation degrees (ICD) were synthesized and their homogeneous polyelectrolyte complex membranes (HPECMs) were fabricated. Elemental analysis and FT-IR were used to determine the composition and chemical structure of PECs. Thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD) and viscometry were used to characterize the thermal stability, crystallinity and solution properties of PECs, respectively. Field emission scanning electron microscope (FESEM) was used to examine the surface morphology of HPECMs, which were subjected to the pervaporation dehydration of isopropanol. Effects of membrane fabrication methods, cycling of feed temperature and ICD of PECs on pervaporation performance of HPECMs are discussed. Meanwhile, HPECMs were also subjected to dehydration of three other organics and showed very good performance. All these performances are explained in terms of the unique structural characteristics of PECs and HPECMs.