Synthesis and Characterization of Cellulose-Based Hydrogels to Be Used as Gel Electrolytes

Abstract

Cellulose-based hydrogels, obtained by tuned, low-cost synthetic routes, are proposed as convenient gel electrolyte membranes. Hydrogels have been prepared from different types of cellulose by optimized solubilization and crosslinking steps. The obtained gel membranes have been characterized by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mechanical tests in order to investigate the crosslinking occurrence and modifications of cellulose resulting from the synthetic process, morphology of the hydrogels, their thermal stability, and viscoelastic-extensional properties, respectively. Hydrogels liquid uptake capability and ionic conductivity, derived from absorption of aqueous electrolytic solutions, have been evaluated, to assess the successful applicability of the proposed membranes as gel electrolytes for electrochemical devices. To this purpose, the redox behavior of electroactive species entrapped into the hydrogels has been investigated by cyclic voltammetry tests, revealing very high reversibility and ion diffusivity.

Cellulose-based hydrogel materials: chemistry, properties and their prospective applications

“…Hydrogel from chitosan crosslinked with polyacrylic acid has been used in the fuel cell as a membrane for facilitating ion exchange mechanism (Smitha et al 2004 ). Navarra et al ( 2015 ) prepared CB hydrogel crosslinked with epichlorohydrin for gel electrolyte membrane applications. Hydrogels are applied to ease water purification process; for example, hydrogel prepared from guar gum has been proposed for water separation from wastewater (oil–water) by coating stainless steel mesh to render an excellent underwater oleophobicity and super-low oil sticking.…”

Dehydration of bacterial cellulose and the water content effects on its viscoelastic and electrochemical properties

“…Additionally, the hydroxyl groups also interact with each other, establishing intra- and inter-molecular hydrogen bonds to form amorphous and crystalline domains, respectively [ 3,4 ]. Because of the higher number of crystalline domains, BC is very strong under tensile load yet flexible and insoluble in almost all solvents, including water [ 4 ]. The numerous hydroxyl groups contribute further to the reactivity of BC, allowing straightforward modification and functionalisation via incorporation of monomeric and/or other reactive species, such as of polymers, carbon nanotubes, graphene and metal nanoparticles, into the BC network [ 5 ].…”

Electrodes and hydrogel electrolytes based on cellulose: fabrication and characterization as EDLC components

“…Gel electrolytes exhibit liquidlike ionic conductivity mechanism and can provide shape flexibility of a solid system. It functions as both a separator and an ionic conductor between electrodes [22][23][24][25][26].…”