Synthesis of a Nitrile- and Ether-Rich Covalent Organic Framework as a Filler and Its Application for Proton Exchange Membranes

In the fabrication of proton exchange membranes (PEMs), incorporating nanomaterials into the polymer matrix is a promising strategy for enhancing membrane stability. However, this approach often results in a trade-off with proton conductivity. To address this limitation and develop efficient additives, we synthesized a novel covalent organic framework with a high density of ether and nitrile groups (COF-EN) via nucleophilic substitution as a nanofiller. This nanofiller was specifically designed to enhance both the proton conductivity and the stability of the membranes. The chemical structure of the synthesized COF-EN was confirmed through various analytical techniques, and it was subsequently integrated into a sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate advanced composite membranes. The resulting membranes demonstrated enhanced dimensional, thermal, and oxidative stab…