Poly(vinyl alcohol)‐based membranes for fuel cell and water treatment applications: A review on recent advancements

Abstract

Clean water and energy are two of the most important requirements for human survival. Membrane‐based filtration represents one of the advanced technologies involved in water decontamination; while, polymer electrolyte membrane fuel cells (PEMFCs) are among the frontrunners in the alternative and renewable energy domain. It is evident that membrane‐based processes provide sustainable solution to the ever‐increasing demand of energy and clean water. Over the years, it has been realized that synthetic poly(vinyl alcohol) (PVA) is one of the potential candidates for the development of membranes, owing to its hydrophilicity, barrier property, film forming ability, crosslinking ability, biodegradability, and low cost. These properties have been widely explored for the fabrication of polymer electrolyte membranes for PEMFCs, in order to improve the ionic conductivity and methanol barrier property, as well as, to reduce the membrane fabrication cost. On the other hand, high water solubility and film forming characteristics of PVA have been used for the formation of water treatment membranes, for enhancing the antifouling property and chemical stability. This review provides in‐depth discussions and analyses on the structure and properties of various PVA‐based copolymers, and their applications as membrane materials for PEMFCs (including direct methanol and alkaline fuel cells) and water remediation.

Polymer electrolyte membrane modification in direct ethanol fuel cells: An update

“…The most important properties found on PVA membranes can minimize the ethanol permeability and dehydration problems associated with the commercial membrane. 54,55 However, two significant shortcomings of PVA polymers must be addressed to perform high excellence of the polymer electrolyte membrane: low membrane conductivity and mechanical stability. The hydrophilic properties of PVA make excess water absorption occur, resulting in the swelling ratio.…”

“…PVA also has high flexibility, a large surface area, and strong abrasion resistance. The most important properties found on PVA membranes can minimize the ethanol permeability and dehydration problems associated with the commercial membrane 54,55 . However, two significant shortcomings of PVA polymers must be addressed to perform high excellence of the polymer electrolyte membrane: low membrane conductivity and mechanical stability.…”

Aliphatic Anion Exchange Ionomers with Long Spacers and No Ether Links by Ziegler–Natta Polymerization: Properties and Alkaline Stability

“…The intrinsic properties of PVA, such as water solubility, nontoxicity, biodegradability, film forming properties, and low cost, make it an excellent choice. Its ability to form composites and the common use as an absorbent for alkaline solutions, giving it ionic conducting properties, make it appropriate for our purpose [75][76][77].…”

Investigation of Hydronium Diffusion in Poly(vinyl alcohol) Hydrogels: A Critical First Step to Describe Acid Transport for Encapsulated Bioremediation

“…Crystalline regions are impermeable to solute diffusion and have been shown to hinder solute diffusion, while amorphous regions are more flexible but act as roadblocks to solute diffusion. Poly­(vinyl alcohol) (PVA) hydrogels are commonly used in cryogel and chemically crosslinked hydrogel studies. − Previous work by Schuszter et al investigated hydronium diffusion in non-PVA hydrogels, and Choudhury et al , Ajith et al , and Wang et al measured hydronium conductivity in PVA hydrogels but did not quantify hydronium diffusivity, a critical knowledge gap in these materials. NMR analysis of hydronium diffusion in aqueous systems is common, but this technique is infeasible in hydrogel systems because the high water content in the hydrogel would mask the hydronium signal …”