PEDOT类高强度导电聚合物水凝胶的设计合成及电致变色器件

导电聚合物水凝胶力学性能及生物相容性优良、兼具光电功能，有望实现可拉伸电致变色器件的功能升级，用于可穿戴变色设备等产品研发。然而现有导电聚合物水凝胶的电致变色性能及机理尚不清晰，且机械强度普遍较差、与人体组织的力学匹配性尚待提高。在前期研究确定导电聚合物水凝胶电致变色功能的基础上，本项目拟选取电致变色性能及稳定性优异的聚(3,4-二氧乙撑噻吩)（PEDOT）类导电聚合物为主体结构，通过引入可交联或可聚合取代基、嵌段共聚等结构修饰策略建立合理的单网络、二元网络聚合物链结构，合成系列高强度导电聚合物水凝胶新材料，以期获得电致变色功能、力学性能及生物相容性的有效结合和同步提高。揭秘此类材料的电致变色机制以及分子结构-应变-性能关联规律等基本科学问题；构建可拉伸水凝胶电致变色器件，探索制作可变色人造皮肤、变色纹身等产品，为高性能电致变色水凝胶的研发提供理论指导与材料、技术支撑。

Owing to excellent mechanical properties, biocompatibility and optoelectronic performances, conducting polymer hydrogels are expected to further improve the performances of stretchable electrochromic devices suffice for real applications such as wearable and implantable electrochromic bioelectronic devices. However, the electrochromic properties and mechanism of such intriguing materials are still unclear so far. Also, most of the existing conducting polymer hydrogels are mechanically brittle and their mechanical compatibility with human tissues are still need to be improved. Previously we experimentally achieved the hydrogel-based electrochromic devices and verified the feasibility of employing conducting polymer hydrogels as electrochromic materials. In order to achieve the synchronous improvement in mechanical properties, electrochromic performances and biocompatibility, we herein propose to design and synthesize novel tough, biocompatible and conductive polymer hydrogels based on poly(3,4-ethylenedioxythiophene) and its derivatives (PEDOT, one of the best conducting polymers in terms of conductivity, electrochromic performance and stability) by combining the concept of both covalent cross-linking and dynamic hydrogen bonding (non-covalent cross-linking). Molecular modification strategies like the introduction of cross-linkable substituents, grafting or block copolymerization will be employed to achieve well-distributed single or dual polymer network. The synthetic methodology of such PEDOT-based hydrogels will be established for pursuing inherently tough, stretchable, conductive and electrochromic hydrogels with better performances in future. Structural characterization and the properties of the resultant hydrogels including electrical, electrochemcial, mechanical, and electrochromic properties, will be investigated minutely. The structure-property and strain-property relationship of these materials will also be explored to provide both fundamental and technical guidance for future research. Moreover, stretchable electrochromic devices will be fabricated with those hydrogels with superior performance, and their fabrication technology and working conditions will be further optimized carefully. We will also devote ourselves to exploring novel practical applications of these devices such as electrochromic artificial skin and color-changing tattoos, providing some technical guidance for future commericalization of stretchable electrochromics.