Preparation of chitosan‐modified core–shell SiO2‐acidic polymer multiple crosslinked membranes.

This article prepares and studies a series of chitosan‐modified core–shell SiO2‐acidic polymer multiple crosslinked membranes (modified membranes). The preparation process is simple, low cost, and environmentally friendly. The multiple crosslinking enhances the thermal stability and mechanical strength of membranes. TGA shows that the 10% weight loss temperatures of modified membranes are above 300 °C. Compared with water uptake, the methanol absorption of modified membranes is lower and decreases with increasing methanol concentration, which is very beneficial to their use in direct‐methanol fuel cells. The lowest methanol diffusion coefficient of the modified membrane is 4.56 × 10−8 cm2 s−1, which is only about 1/50th of that of Nafion117. In addition, the membranes exhibit feasible proton conductivity and higher selectivity than Nafion117. These results indicate that the chitosan‐modified core–shell SiO2‐acidic polymer multiple crosslinked membranes have potential applications in direct‐methanol fuel cells. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48494. [ABSTRACT FROM AUTHOR]