Nguyen Nhat Hong, Huang Chih-Feng, Jamnongkan Tongsai
Department of Chemical Engineering, i-Center for Advanced Science and Technology (iCAST), National Chung Hsing University, Taichung 40227, Taiwan.
Graduate Program in Semiconductor and Green Technology, Academy of Circular Economy, National Chung Hsing University, Nantou City 540216, Nantou County, Taiwan.
Polymers (Basel). 2025 Jul 13;17(14):1930. doi: 10.3390/polym17141930.
Anion exchange membranes (AEMs) are vital for electrochemical energy devices such as alkaline fuel cells and water electrolyzers, enabling the use of non-precious metal catalysts despite challenges from alkaline degradation. Hyperbranched polymers (hbPs) with their globular structure, high functional group density, and simple synthesis, offer a promising platform for enhancing transport and stability. In this study, multifunctional hbPs were synthesized from 4-vinylbenzyl chloride (VBC) and 2-hydroxyethyl methacrylate (HEMA) via atom transfer radical self-condensing vinyl polymerization (ATR-SCVP) and crosslinked into polyurethane-based AEMs. Characterization confirmed successful copolymerization and crosslinking, with excellent alkaline stability. Membranes crosslinked with higher molecular weight (MW) and VBC-richer hbPs (e.g., OH-hbP1-PU) exhibited high water uptake (75%) but low ion-exchange capacity (1.54 mmol/g) and conductivity (186 µS/cm), attributed to steric hindrance and insufficient ionic network connectivity. In contrast, OH-hbP2-PU exhibited optimal properties, with the highest OH conductivity (338 µS/cm) and IEC (2.64 mmol/g), highlighting a balanced structure for efficient ion transport. This work offers a tunable strategy for high-performance AEM development through tailored hbP architecture.
阴离子交换膜（AEMs）对于诸如碱性燃料电池和水电解槽等电化学能量装置至关重要，尽管存在碱性降解带来的挑战，但它能使非贵金属催化剂得以应用。具有球状结构、高官能团密度且合成简单的超支化聚合物（hbPs）为增强传输和稳定性提供了一个有前景的平台。在本研究中，通过原子转移自由基自缩合乙烯基聚合（ATR-SCVP）由4-乙烯基苄基氯（VBC）和甲基丙烯酸2-羟乙酯（HEMA）合成了多功能hbPs，并将其交联成基于聚氨酯的AEMs。表征证实了成功的共聚和交联，具有优异的碱性稳定性。与较高分子量（MW）且富含VBC的hbPs交联的膜（例如OH-hbP1-PU）表现出高吸水率（75%）但低离子交换容量（1.54 mmol/g）和电导率（186 µS/cm），这归因于空间位阻和离子网络连通性不足。相比之下，OH-hbP2-PU表现出最佳性能，具有最高的氢氧根电导率（338 µS/cm）和离子交换容量（2.64 mmol/g），突出了一种有利于高效离子传输的平衡结构。这项工作通过定制hbP结构为高性能AEM的开发提供了一种可调节的策略。
