Property improvement of nanocellulose‐reinforced proton exchange nanocomposite membrane coated with tetraethyl orthosilicate

Study on proton exchange membrane (PEM) with the aim toward excellent battery performance of PEM for fuel cells has attracted increasing attention. In this work, nanocellulose (CNC) aminated by KH792 noted as NN was prepared. CNC or NN/sulfophenylated poly(ether ether ketone ketone) (sPEEKK) nanocomposite membrane (SN) or (SNN) were produced by solution mixing. SNN was further coated with tetraethyl orthosilicate (TEOS) to obtain SNNT. The properties of sPEEKK, SN, SNN, and SNNT membranes were thoroughly investigated. The proton conductivity of SN4 was 0.22 S·cm⁻¹ at 90 °C, while a proton conductivity of 0.30 S·cm⁻¹ was obtained for SNN4, and an even higher value of 0.36 S·cm⁻¹ at 90 °C was obtained for the TEOS‐coated SNN4 (SNN4T). Meanwhile, SNN4T showed high thermal stability, and its Td₅ was as high as 318.2 °C. Furthermore, the composite membrane coated with TEOS also presented excellent oxidative stability. The mass of SNN2T after treated in Fenton agent for 1 h at 80 °C was still retained 96.2%, and it was not fully dissolved until 11 h. It was illustrated that aminated CNC/sPEEKK nanocomposite membranes coated with TEOS is a kind of promising materials as PEMs for fuel cells. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2190–2200