Preparation of monovalent cation selective membranes through annealing treatment

Polyvinyl alcohol membranes modified by low-hydroxylated fullerenol C60(OH)12

“…It was calculated that the degree of crystallinity increased with heating from the 45% to the 55% and 54% for PVA-140 and PVA-140/1%, respectively (Table 2). This observation correlates with the results published [27], where changes in the crystallinity of PVA membranes after annealing were studied. At high temperatures hydrogen bonding can be disrupted and macromolecular mobility may increase causing crystallization [28].…”

A novel nanofiltration membrane inspired by an asymmetric porous membrane for selective fractionation of monovalent anions in electrodialysis

“…The mechanism of these studies is principally focused on the difference of hydrated ionic radius and valence, based on the sieving and electrostatic repulsion, respectively. 8,[13][14][15][16] The most explored strategy is the modication of the membrane surface, 17,18 which is mainly dependent on the method of depositing a negatively or positively charged layer on the surface of a commercial anion exchange membrane or a labmade anion exchange membrane. 8,14,16,19 For example, Shahi et al 19 found that a thin polypyrrole layer was useful to increase the permselectivity of a modied membrane (from 0.747 to 0.889).…”

PPO/PVA hybrid membranes for application in bipolar membrane electrodialysis

“…The peak at 1,465 cm -1 is due to the stretching of CH 3 -, -CH 2 -and -CH-groups (δ), and the intensity is stronger for membrane Q due to its -N + (CH 3 ) 3 groups. Another two peaks at 1,095 and 1,035 cm -1 are due to the Si-O-Si and Si-O-C vibrations [27], indicating the formation of silica network. Besides, a significant peak at 1,065 cm -1 appears for membrane S, which is due to the S=O bonds of -SO 3 H groups [28].…”