Abstract Electroactive hydrogels have received increasing attention due to the possibility of being used in biomimetics, such as for soft robotics and artificial muscles. However, the applications are hindered by the poor mechanical properties and slow response time. To address these issues, in this study, supramolecular ionic polymer–carbon nanotube (SIPC) composite hydrogels were fabricated via in situ free radical polymerization. The polymer matrix consisted of carbon nanotubes (CNTs), styrene sulfonic sodium (SSNa), β-cyclodextrin (β-CD)-grafted acrylamide, and ferrocene (Fc)-grafted acrylamide, with the incorporation of SSNa serving as the ionic source. On applying an external voltage, the ions accumulate on one side of the matrix, leading to localized swelling and bending of the structure. Therefore, a controllable and reversible actuation can be achieved by changing the applied voltage. The tensile strength of the SIPC was improved by over 300%, from 12 to 49 kPa, due to the reinforcement effect of the CNTs and the supramolecular host–guest interactions between the β-CD and Fc moieties. The inclusion of CNTs not only improved the tensile properties but also enhanced the ion mobility, which lead to a faster electromechanical response. The presented electro-responsive composite hydrogel shows a high potential for the development of robotic devices and soft smart components for sensing and actuating applications.

中文翻译：

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具有增强机电性能的超分子离子聚合物/碳纳米管复合水凝胶

摘要 由于可用于仿生学，例如软机器人和人造肌肉，电活性水凝胶受到越来越多的关注。然而，由于机械性能差和响应时间慢而阻碍了应用。为了解决这些问题，本研究通过原位自由基聚合制备了超分子离子聚合物-碳纳米管（SIPC）复合水凝胶。聚合物基质由碳纳米管 (CNT)、苯乙烯磺酸钠 (SSNa)、β-环糊精 (β-CD) 接枝的丙烯酰胺和二茂铁 (Fc) 接枝的丙烯酰胺组成，并掺入 SSNa 作为离子源。在施加外部电压时，离子在基质的一侧积累，导致结构局部膨胀和弯曲。所以，通过改变施加的电压可以实现可控和可逆的驱动。由于 CNT 的增强作用以及 β-CD 和 Fc 部分之间的超分子主客体相互作用，SIPC 的拉伸强度提高了 300% 以上，从 12 kPa 提高到 49 kPa。碳纳米管的加入不仅改善了拉伸性能，而且增强了离子迁移率，从而导致更快的机电响应。所提出的电响应复合水凝胶显示出开发用于传感和驱动应用的机器人设备和软智能组件的巨大潜力。由于碳纳米管的增强作用以及 β-CD 和 Fc 部分之间的超分子主客体相互作用。碳纳米管的加入不仅改善了拉伸性能，而且增强了离子迁移率，从而导致更快的机电响应。所提出的电响应复合水凝胶显示出开发用于传感和驱动应用的机器人设备和软智能组件的巨大潜力。由于碳纳米管的增强作用以及 β-CD 和 Fc 部分之间的超分子主客体相互作用。碳纳米管的加入不仅改善了拉伸性能，而且增强了离子迁移率，从而导致更快的机电响应。所提出的电响应复合水凝胶显示出开发用于传感和驱动应用的机器人设备和软智能组件的巨大潜力。