Tuning the Performance of Nanofiller Reinforced Phosphorylated Chitosan-Based Proton Exchange Membrane

Abstract

A one-step method was enforced for the phosphorylation of chitosan (CS) using ATMP, and later amino-functionalized multi-walled carbon nanotubes (MWCNTs-NH2) were used for the fabrication of PCS/N-MWCNTs membranes. The phosphorylation of CS and later PCS/N-MWCNTs nanocomposite membranes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and transmission electron microscopy. They were also evaluated for their mechanical properties, water uptake, area swelling ratio, ion-exchange capacity (IEC), and proton conductivity. Interfacial interaction among an -NH2 group of MWCNTs and -phosphonic acid as well as the -NH2 group of PCS provided extra sites for proton transfer, thus improving the proton conductivity of PCS/N-MWCNTs membranes. These results revealed that the incorporation of N-MWCNTs into PCS chains lowers PCS chain mobility and ultimately improved the thermal and mechanical properties of the composite membranes. The proton conductivity of the composite membrane with 5 wt. % of N-MWCNTs at 80°C was 0.045 S.cm−1. Thus, PCS/N-MWCNTs nanocomposite membranes as a PEM can be used in fuel cells. With this advantage, the N-MWCNTs-filled hydrogen fuel cell outperforms compared to PCS filled membrane.

Polyelectrolyte Membranes Based on Nafion/Chitosan Blends for Direct Methanol Fuel Cell Application

“…As one of the copious natural polymers, chitosan is the topic of numerous academic and industrial research in a broad array of applications, including the development of renewable energy sources. 3,14 Chitosan, obtained from abundant chitin, is a suitable biobased polymer for developing novel PEMs due to its relatively high thermal stability, inherent hydrophilicity, low cost, good film-forming ability, low methanol permeability, and available functionalities for further modifications. 15,16 Unfortunately, due to the lack of mobile protons in its native structure, chitosan has low proton conductivity and cannot be used as a PEM straightforwardly.…”

Comparative Study on the Proton Conduction Behaviors of Two Acidic Amphiphilic and Hydrophilic Coordination Compounds in Nafion Composite Membranes

“…The membranes’ WU and AS ratio were assessed by determining the weight and area variances between wet and dry samples, in accordance with literature. , The membrane was immersed in ultra pure water for a week, then immediately weighed and measured to obtain the W wet and A wet values after wiping the surface water with filter paper. The W dry and A dry values were measured prior to immersing.…”