Abstract Ionomeric polymer/metal composites (IPMCs) are smart materials that deform in response to electrical stimuli and vice versa. Its electromechanical performance depends on several factors, such as the electrical stimulus, environment humidity, counterions, and the number of actuation cycles. For this reason, in this paper, the electromechanical response of Pt-Nafion® IPMC samples was evaluated using several counterion types (H+, Li+, Na+, K+ and Ionic Liquid) and relative humidities. Results showed that the electromechanical behaviour of the IPMC was strongly influenced by the counterion type and polymer matrix hydration level (RH). Blocking force, Electric Charge Storage and the Coulombic Efficiency of the devices increased with the reduction of counterion ionic radius and increase of the hydration level of the polymeric matrix. An atypical current response, associated with water electrolysis, was observed for samples incorporated with H+ counterion. The mechanical performance decreased with the number of cycles, showing a limited life cycle for the device. SEM images presented that Pt surface cracks density increases after several actuations, harming the performance of the IPMC. As the main conclusion, this work shows that the hydration level and the counterion type exert a great influence on IPMC electromechanical properties, being the hydration level more prevailing than counterion.

中文翻译：

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反离子和湿度对 Nafion®/Pt 复合材料机电性能的影响

摘要 离聚物/金属复合材料 (IPMC) 是一种智能材料，可响应电刺激而变形，反之亦然。其机电性能取决于几个因素，例如电刺激、环境湿度、反离子和驱动周期数。因此，在本文中，使用多种抗衡离子类型（H+、Li+、Na+、K+ 和离子液体）和相对湿度评估了 Pt-Nafion® IPMC 样品的机电响应。结果表明，IPMC 的机电行为受反离子类型和聚合物基体水合水平 (RH) 的强烈影响。随着抗衡离子半径的减小和聚合物基质水化水平的增加，器件的阻断力、电荷存储和库仑效率增加。对于掺入 H+ 抗衡离子的样品，观察到与水电解相关的非典型电流响应。机械性能随着循环次数的增加而下降，表明设备的生命周期有限。SEM 图像显示 Pt 表面裂纹密度在多次驱动后增加，损害了 IPMC 的性能。作为主要结论，这项工作表明，水合水平和反离子类型对 IPMC 机电性能有很大影响，水合水平比反离子更占优势。SEM 图像显示 Pt 表面裂纹密度在多次驱动后增加，损害了 IPMC 的性能。作为主要结论，这项工作表明，水合水平和反离子类型对 IPMC 机电性能有很大影响，水合水平比反离子更占优势。SEM 图像显示 Pt 表面裂纹密度在多次驱动后增加，损害了 IPMC 的性能。作为主要结论，这项工作表明，水合水平和反离子类型对 IPMC 机电性能有很大影响，水合水平比反离子更占优势。