Structural modification of chitosan biopolymer as a novel polyelectrolyte membrane for green power generation

Abstract

In the present study, a series of bioresource polyelectrolytes based on chitosan were synthesized and assessed for applicability in direct methanol fuel cells (DMFCs). A binary cross-linking agent (sulfosuccinic acid/glutaraldehyde) was used for the structural modification of chitosan and membranes comprising various amounts of sulfosuccinic acid (0, 8, 12, and 16 wt% SSA/wt chitosan) were prepared. It was found that by increasing the sulfonate groups' content up to 16 wt%, proton conductivity and methanol permeability properties reach the values of 0.0452 S cm S1 and 9.6 T 10 S7 cm 2 sec S1 , respectively. Based on the membrane selectivity evaluation and activation energy measurements of proton conduction, the optimum composition of cross-linking agent was determined. The optimum composition resulted in a relatively high proton conductivity of 0.0452 S cm S1 and a low methanol permeability of 9.6 T 10 S7 cm 2 sec S1 . Moreover, the optimum proton exchange membrane exhibited selectivity value of 47,100 in comparison with the corresponding value of 40,500 for Nafion 1 117. The fabricated membranes showed acceptable oxidative and hydrolytic stability. Furthermore, single cell DMFC performance test revealed a power density of 17 mW cm S2 at 30-C and 41 mW cm S2 at 60-C in a 2 M methanol feed. Hence, prepared proton-conducting bioresource ionomers could have promising potential in the field of green power generation as a low cost and biodegradable polyelectrolyte.

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

“…) after 120 h in a high concentration of Fenton's reagent, and is thus much stronger than other sulfonated polymers that typically decompose after 24-60 h. The optimum membrane possessed a high selectivity for methanol fuel cells With its distinct advantages in forming an excellent alcohol barrier while maintaining acceptable ion conductivity properties, chitosan (CS) has been used for the polymer matrix of PEMs [39] (Table 4; 17). Various compositions of sulfosuccinic acid (SSA) and GA were introduced into CS as a binary crosslinking agent to form CS network membranes.…”

“…To solve the low conductivity and high swelling problems, CS was usually either ionically crosslinked with sulfuric acid [33,34] or incorporated into inorganic particles [35][36][37][38]. In addition, different Chitosan-based PEMs have been studied and have showed promising properties for application in the field of PEMFCs [39][40][41][42].…”

Chitosan, Chitosan Derivatives and their Biomedical Applications

“…The cross-linking of chitosan with glutaraldehyde and sulfosuccinic acid has been used to generate membranes with a good proton conductivity, which makes them useful in fuel cells [44]. Genipin, a compound extracted from the fruit of Gardenia jasminoides and American Genipa has also been used as cross-linker agent [45].…”

Chitosan-ABS membrane for DMFC: Effect of sulfonation time and mass ratio of chitosan and ABS

“…This natural polymer has already been widely used in the pharmaceutical field, separation technology, and water treatment. Recently, chitosan attracts attention for its use as a proton exchange membrane material because of its unique properties, such as hydrophilic, good thermo-chemical stability, easily modified, low methanol permeability, and reasonable price [12,13].…”