Cross-Linked Poly(vinyl alcohol)−Poly(acrylonitrile-co-2-dimethylamino ethylmethacrylate) Based Anion-Exchange Membranes in Aqueous Media

Abstract

Hydroxide anion conducting polymer membranes also termed as anion exchange membranes (AEMs) are recently becoming important materials for electrochemical technology, alkaline fuel cells, and electrolyzers. In this work, the preparation procedure for AEMs based on poly(vinyl alcohol) (PVA) and copolymer of poly(acrylonitrile (PAN)-dimethylamino ethylmethacrylate) (DMAEMA) with strongly basic quaternary ammonium in aqueous media has been reported. This simplified procedure avoids the use of chloromethyl methyl ether (CME), a carcinogen that is harmful to human health, generally used for chloromethylation during AEM preparation. Developed AEMs were extensively characterized by studying physicochemical and electrochemical properties, to assess their suitability for electrodialytic ion separation. These membranes were designed to possess all the required properties of a highly anion conductive membrane such as reasonable water uptake, good ion-exchange capacity (1.18 mequiv g(-1)), high permselectivity (0.90), along with reasonable conductivity (3.45 mS cm(-1)) due to quaternary ammonium group functionality. The membrane conductivity values in conjunction with solution conductivity have been used for the estimation of the isoconductivity point, considering the membrane as a combination of the gel phase and integral phase. Electroosmotic studies revealed quite low mass drag and equivalent pore radius (2.7-4.0 A) of the membrane, which are also desirable properties of an AEM. The excellent electrotransport property of AEM-70 for practical anion separation was concluded from i-v studies. Electrodialytic performance of the AEM-70 membrane revealed its suitability for applications in electromembrane processes.

Functionalized biopolymer based bipolar membrane with poly ethylene glycol interfacial layer for improved water splitting

“…The detailed procedure for the determination of water uptake, ion-exchange capacity (IEC) surface charge density [29] and diffusion coefficient [34] are included in S1 (supporting information). Counter ions transport number in the membrane phase was obtained by Hittorf method [34].…”

“…Counter ions transport number in the membrane phase was obtained by Hittorf method [34]. Experimental cell used for the determination of transport number was two asymmetric compartments separated by a circular piece of membrane (25 cm 2 ) and electrodes.…”

“…W, for producing (acid or base) in EDBPM process may be obtained by using following equation [34]: Fig. 10(A and B) depicts Á and W values for 0.50 M NaCl dissociation into corresponding HCl and NaOH at constant applied potential (7.0 V).…”

Crosslinked poly(vinylbenzyl chloride) with a macromolecular crosslinker for anion exchange membrane fuel cells

“…The semi-IPN was formed by combining a thermally, mechanically and chemically stable polymer with a hydroxide conducting polymer, and only one of the polymers is crosslinked [4]. Several researchers have found that semi-IPN membrane presented improved performances with good mechanical properties [11][12][13][14]. However, it would be difficult for the two polymers to distribute uniformly in the semi-IPN membrane owing to the absence of crosslinking between them, thus resulting in the phase seperation of the two components and decrease of the membrane performances.…”

High-performance alkaline fuel cells using crosslinked composite anion exchange membrane

“…As we know, Nafion is a strong acid in nature, which only allows noble metals to be used as the compatible catalyst, thus increasing the cost hinders their further application. To solve this problem, AEMFC has begun to attract a lot of attention recently, because some non-noble metals with high kinetic activity for both the fuel oxidation and oxygen reduction in alkaline environment can be applied [6,7].…”