Fabrication of dense anion exchange membranes by filling polymer matrix into quaternized branched polyethyleneimine @cellulose aerogel through in-situ polymerization

AbstractIn order to construct interconnected three-dimensional ion transport structures within anion exchange membranes (AEMs), we proposed the idea of preparing AEMs by filling the aerogel three-dimensional network skeleton by in-situ polymerization. First, quaternized branched polyethyleneimine (QBPEI) with a large number of quaternary ammonium groups was cross-linked with cellulose to construct an aerogel with a three-dimensional network. Then, poly(4-vinylbenzyl chloride) (PVBC) was filled into the aerogel network through in-situ polymerization. Finally, dense AEMs with internal three-dimensional ion transport networks were prepared by hot pressing PVBC/QBPEI@cellulose. The prepared AEMs have low ion exchange capacity (IEC) values and high ionic conductivities, with the membrane with the best overall performance (IEC value of 1.58 meq./g) having a maximum hydroxide conductivity of 38.88 mS/cm at 80 °C. In addition, the optimized membrane has good chemical and dimensional stability, and the maximum power density of the fuel cell assembled based on it is 46.32 mW/cm2. Although the performance of the prepared composite membranes needs to be further improved due to the preparation process, the design idea in this work provides a feasible solution for the construction of continuous ion fast transport channels in AEMs.Keywords: anion exchange membranequaternized branched polyethyleneiminecellulose aerogelhot pressingpoly(4-vinylbenzyl chloride) Associated contentSupporting information is available free of charge.Author contributionsWenting Lan: Data curation, Writing- Original draft preparation; Dawei Dong: Writing- Reviewing and Editing; Minghua Zhang: Methodology and Software; Yafei Xiao: Conceptualization and Methodology; Zhixin Zhao: Visualization, Investigation; Zhaojie Yang: Software and Validation; Ya Cao: Supervision and Data curation; Minmin Fan: Writing- Reviewing and Editing.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was financially supported by the National Natural Science Foundation of China [No. 51803136], Sichuan Science and Technology Program [No. 2021YFG0245] and the Fundamental Research Funds for the Central Universities [No. 2022SCUH0001].