Synthesis and properties of chitosan membranes modified by reactive cationic dyes as a novel alkaline exchange membrane for low temperature fuel cells

Using 1-aminoanthraquinone, cyanuric chloride, dimethyl propylene diamine, diethyl sulfate as reactants, a reactive cationic dye (RCD) was synthesized. Then the dye prepared was used to modify the pristine chitosan (CTS) membrane to synthesize a novel alkaline exchange membrane for low temperature fuel cells. The performance of the prepared membranes was researched in details. FTIR and SEM were used for chemical and structural characterization of the membranes while thermo gravimetric analysis was adopted to study the membranes' thermal stability. The properties of the membranes such as OH− conductivity (σ), water uptake (WU), ion exchange capacity (IEC) and mechanical property were also investigated systematically to evaluate their application performances. The results showed that the OH− conductivity of the membrane (52 μm) can reach 4.59 × 10−3 S cm−1 and increase with the temperature increasing from 30 °C to 80 °C. After immersing the CTS/RCD membrane (52 μm) in the KOH solution (80 °C, 8 mol L−1) for 300 h, the OH− conductivity of the membrane didn't decrease, on the contrary, it increased to 1.057 × 10−2 S cm−1, which indicated that the membrane had the excellent stability to resist the strong alkaline lye.