含亲水柔性支链苯并咪唑功能基团阴离子交换膜的制备及表征  

Preparation and Characterization of Hydrophilic Flexible Branched Benzimidazole Functional Groups Anion Exchange Membranes

作　　者：王庭昀 Wang Tingyun(Shanxi Energy Institute,Taiyuan Shanxi 030000)

机构地区：[1]山西能源学院,山西太原030000

出　　处：《山西化工》2023年第3期8-13,共6页Shanxi Chemical Industry

基　　金：2022年山西省高等学校教学改革创新项目(J20221255)。

摘　　要：阴离子交换膜燃料电池具有氧化还原效率高且无需贵金属作催化剂的优点,因此得到了极大的关注,但作为核心部件之一的阴离子交换膜仍面临着离子电导率低和碱稳定性差等挑战。本研究首先采用两步法合成了1-[2-(2-甲氧基乙氧基)乙基]-2-甲基苯并咪唑,在2-甲基苯并咪唑单体N3位置引入亲水柔性支链,再将单体接枝在聚砜主链制备阴离子交换膜,制得的膜展现出较高的碱稳定性及离子电导率。PSf-OH-135膜在室温下电导率为12.05 mS/cm,60℃时增加到18.92 mS/cm。亲水柔性支链使膜吸水性增加,且与聚醚主链相互作用,膜内形成有利于高效离子传输的微相分离结构;PSf-OH-120膜浸泡在80℃1 mol L^(-1)KOH溶液336 h后,电导率仍保持84.7%。较长的柔性支链聚集在正电中心附近,相互缠绕,阻碍了OH-的进攻,使膜的碱稳定性较高。该类阴离子交换膜有望应用于碱性阴离子交换膜燃料电池领域。Anion exchange membrane fuel cells(AEMFCs)have attracted worldwide attention due to their high redox efficiency and non-precious catalysts employment.However,as one of the core components,the anion exchange membrane still faces challenges such as the poor ionic conductivities and the alkaline stability.Herein,we synthesized 1-[2-(2-methoxyethoxy)ethyl]-2-methylbenzimidazole by a two-step method,which contains a hydrophilic flexible branch at the N3 position of the 2-methylbenzimidazole monomer,and then grafted the monomer to the polysulfone backbone to prepare anion exchange membrane,which exhibited high alkali stability and ionic conductivity.It was found that the conductivity of the PSf-OH-135 membrane was 12.05 mS/cm at room temperature and increased to 18.92 mS/cm at 60℃.The hydrophilic and flexible branched chains increase the water absorption of the membrane,and interact with the polyether backbone to form a microphase separation structure which is conducive the efficiency for ion transport in the membrane;the hydroxide conductivity of PSf-OH-120 membrane still keeps 84.72%of the original ionic conductivity values after being kept in 1 mol·L^(-1) KOH solution at 80℃for 336 h.The flexible branches congregate near the positively charged center and entangle with each other,improving alkaline stability which hinders the attack of OH-.In conclusion,this type of anion exchange membrane shows a great potential for application in anion exchange membrane fuel cells.

关 键 词：苯并咪唑 阴离子交换膜 离子电导率 碱稳定性 

分 类 号：TM911.4[电气工程—电力电子与电力传动]