Zheng Sheng, Lin Yu-Liang, Chang Chun-Chi, Lee Min-Jie, Chen Yi-Fan, Lee Lin-Ruei, Chang Ming-Hsuan, Chen Jiun-Tai
Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.
Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.
ACS Appl Mater Interfaces. 2023 Sep 27;15(38):45418-45425. doi: 10.1021/acsami.3c08792. Epub 2023 Sep 7.
Exploring stimuli-responsive ion-conductive materials is a challenging task, but it has gained increasing attention because of their enormous potential applications in actuators, sensors, and smart electronics. Here, we demonstrate a distinctive photoresponsive ion-conductive device that utilizes azobenzene-based ionic liquids ([AzoCMIM][Br], where = 2, 6, and 10), confined in nanochannels of anodic aluminum oxide (AAO) templates for photoisomerization. The structure of [AzoCMIM][Br] comprises photoresponsive and hydrophobic azobenzene moieties, hydrophilic imidazolium cations, and negatively charged bromide ions. Therefore, [AzoCMIM][Br] can form micelles and exhibit photoresponsive ion conductivities. The nanochannels of AAO templates exhibit a confinement effect on the formation of azobenzene-based ionic liquid micelles due to the pore size, thereby preventing the formation of larger micelles that could lead to a decrease in conductivity. Consequently, the ion conductivities of the azobenzene-based ionic liquids are higher in the nanochannels of the AAO templates. The effects of the length of carbon chains on the azobezene-based ionic liquids and the pore size of the AAO templates have also been investigated. Additionally, through irradiation with UV/vis light, [AzoCMIM][Br] can undergo reversible isomerization, thereby reversibly changing the sizes of the micelles and subsequently altering the ion conductivities.
探索刺激响应型离子导电材料是一项具有挑战性的任务，但由于其在致动器、传感器和智能电子领域的巨大潜在应用，该领域已受到越来越多的关注。在此，我们展示了一种独特的光响应型离子导电装置，该装置利用基于偶氮苯的离子液体（[AzoCMIM][Br]，其中 = 2、6和10），将其限制在阳极氧化铝（AAO）模板的纳米通道中进行光异构化。[AzoCMIM][Br]的结构包括光响应性和疏水性的偶氮苯部分、亲水性咪唑阳离子和带负电荷的溴离子。因此，[AzoCMIM][Br]可以形成胶束并表现出光响应离子电导率。由于孔径的原因，AAO模板的纳米通道对偶氮苯基离子液体胶束的形成表现出限制作用，从而防止形成可能导致电导率降低的更大胶束。因此，基于偶氮苯的离子液体在AAO模板的纳米通道中的离子电导率更高。还研究了碳链长度对偶氮苯基离子液体和AAO模板孔径的影响。此外，通过紫外/可见光照射，[AzoCMIM][Br]可以发生可逆异构化，从而可逆地改变胶束的大小，进而改变离子电导率。
