Sulfonic Acid Functionalized Chitosan as a Sustainable Component for Proton Conductivity Management in PEMs

Abstract

One of the most fundamental assets of natural polysaccharides is their water storage capacity. Analogically, materials able to regulate water hydration in energetic systems (e.x.: fuel‐cells) are of paramount interest. In light of this key characteristic, chitosan, an aminocarbohydrate derived from shellfish waste, was structurally conjugated using sulfosuccinic acid to afford CS‐SO3H. The resulting polymeric material appears well suitable for enhancing proton conduction and tuning the hydrophilic‐hydrophobic balance of the proton exchange membranes (PEM). Consequently, Nafion membrane modified with CS‐SO3H presented σH+ values almost 2 times higher than that of pristine Nafion at every % RH level exposed (30 °C ‐ 80 °C and 30% ‐ 90%). The σH+ enhancement is in agreement with the lower activation energy indicating that the proton transport is facilitated in the presence of ‐SO3H modified chitosan. We have found indications that –SO3H modified chitosan polymer, as a sustainable additive to Nafion is able to control the proton conduction mechanism and keep the activation energy for proton conduction at lower values as compared to pristine Nafion.

Facile hydrothermal fabrication of functionalized multi‐layer graphene oxide encapsulated chitosan beads for enriched fluoride adsorption

“…The characteristic band detected at 1151 cm −1 was matched to CO stretching vibrations of COH in chitosan chain. The corresponding intensities of these attribute bands in the FTIR spectra of SGO/CS beads became weak when compared to chitosan, inferring the generation of interfacial attractions such as electrostatic interaction and hydrogen‐bonding between the OH/NH 2 groups of chitosan and SO 3 H acid groups of SGO 40 . Compared with GO, SGO, and SGO/CS beads possess a band at 1198 cm −1 , which was corresponded to the symmetrical stretching vibration of SO − groups.…”

Improving the Immobilization of Glucose Oxidase on Carbon Cloth Via a Hybrid Approach of Cross-Linked Chitosan/TPP Matrices with Na Polymers for High-Performance Self-Pumping Enzyme-Based Biofuel Cells

“…Our result shows that the maximum power density (MPD) of the self-pumping EBFC adopting GOx­[CS/TPP/Na]­CC is 1.077 mW cm –2 , which is higher than that of GOx­[CS/TPP]­CC (0.776 mW cm –2 ) and GOx­[CS/Na]­CC (0.682 mW cm –2 ). Such an improvement of around 57% can be mainly attributed to the capability of cross-linked CS/TPP matrices combined with Na polymers, providing the combined advantages of physical adsorption between CS and GOx , as well as the entrapment of cross-linked CS/TPP matrices and Na polymer for the immobilization of GOx on CC. , …”

“…Such an improvement of around 57% can be mainly attributed to the capability of cross-linked CS/TPP matrices combined with Na polymers, providing the combined advantages of physical adsorption between CS and GOx 67,68 as well as the entrapment of cross-linked CS/TPP matrices 69 and Na polymer for the immobilization of GOx on CC. 70,71 On the other hand, it can be particularly observed that the mass transport loss becomes significant at the GOx[CS/TPP/ Na]CC electrode with the high GOx loading when the selfpumping EBFC is operated at the current density higher than 7 mA cm −2 . This result could be attributed to the finite mass transport rates of the species to or from the electrode through the capillary force during the operation.…”

Enhanced proton transport properties of Nafion via functionalized halloysite nanotubes

“…The proton conductivity of the membranes was evaluated using a laboratory-made conductivity measurement cell [24]. The membrane to be analyzed was placed on the two gold electrodes deposited on an epoxy glass printed circuit.…”