Increasing the Conductivity and Adhesion of Polypyrrole Hydrogels with Electropolymerized Polydopamine
Increasing the Conductivity and Adhesion of Polypyrrole Hydrogels with Electropolymerized Polydopamine
复制标题
DOI：
10.1021/acs.chemmater.9b03655
复制
发表时间：
2020-01-14
影响因子：
8.6
通讯作者：
Liu, Xuqing
中科院分区：
文献类型：
--
作者：
Chalmers, Evelyn;Lee, Haeshin;Liu, Xuqing
聚吡咯（Ppy）水凝胶是开发廉价可穿戴电子产品和生物技术的一种有前途的新途径。特别是，导电聚合物水凝胶的使用可以赋予弹性和高比表面积，从而在传感器、细胞生长支架和能量存储方面具有巨大的潜力。然而，它们的导电率极低（与 Ppy 薄膜和碳或金属微结构相比）、疏水性和低粘附性意味着它们目前不适合大多数生物和可穿戴应用。在这里，我们表明，通过在聚吡咯水凝胶中电聚合共价键合的聚多巴胺 (PDA) 相，与纯聚吡咯水凝胶相比，我们将电导率提高了 2720%，粘附力提高了 2140%。吡咯单体提供了 pi 键稳定性并防止 PDA 的 pi 堆积、自动氧化层形成。相反，通过掺入多巴胺后对聚吡咯凝胶进行动电位极化，我们产生了共价键合的 5,6-二羟基吲哚，从而产生了通过非共价键合与聚吡咯相互作用的共轭聚合物的附加相。 PDA 的未氧化儿茶酚基团也导致水凝胶的亲水性和粘附性增加。这些结果是朝着实现采用简单、可扩展技术制造的全聚合物可穿戴电子产品迈出的又一步，从而消除了对昂贵的、对生物不友好的金属或碳结构的需求。
Polypyrrole (Ppy) hydrogels are a promising new avenue for developing cheap wearable electronics and biotechnology. In particular, the use of conducting polymer hydrogels can impart elasticity and a high specific surface area, leading to great potential for sensors, cell growth scaffolds, and energy storage. However, their significantly low conductivity (compared to Ppy films and carbon or metallic microstructures), hydrophobicity, and low adhesiveness mean that they are currently unsuitable for most biological and wearable applications. Here, we show that by electropolymerizing a covalently bonded polydopamine (PDA) phase within polypyrrole hydrogels, we increased the conductivity by 2720% and adhesion by 2140% compared to pure polypyrrole hydrogels. Pyrrole monomers provided pi-bond stabilization and prevented a pi-stacked, auto-oxidized layer of PDA from forming. Instead, through potentiodynamic polarization of polypyrrole gels after dopamine incorporation, we produced covalently bonded 5,6-dihydroxyindole, producing an additional phase of conjugated polymer that interacted with the polypyrrole through noncovalent bonding. The PDA's unoxidized catechol groups also led to increased hydrophilicity and adhesiveness of the hydrogels. These results are a further step toward the realization of fully polymer wearable electronics made with a simple, scalable technique, thereby removing the need for expensive, biologically unfriendly metals or carbon structures.