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

Abstract

In 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.

Graphical Abstract

Keywords:

• anion exchange membrane
• quaternized branched polyethyleneimine
• cellulose aerogel
• hot pressing
• poly(4-vinylbenzyl chloride)

Associated content

Supporting information is available free of charge.

Author contributions

Wenting 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 statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This 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].