二维碳纳米材料高压原位诱导压电聚合物自组装晶体结构及其智能化研究

The successful development of polymer devices with piezoelectricity depends mainly on the effective fabrication of polar piezoelectric crystalline structures, such as β and γ. In this project, we are going to investigate on the self-assembly process of fluoropolymers at high pressure, induced in situ by graphene, a two dimensional nano-structured carbon material. The aim is to fabricate a series of self-powered smart composite systems, converting biological mechanical energy, acoustic/ultrasonic vibration energy, and biofluid hydraulic energy, prevalent in nature, into electricity. This is to be achived by the multi-level morphological control of the self-assembled piezoelectric crystalline structures during the material processing. Firstly, the transformation of crystalline forms of fluoropolymers in the presence of graphene is to be studied at high pressure, so as to fabricate a fluoropolymer/graphene nano-composite with ultra strong piezoelectricity, resulting from the in situ formed nano-structured polar crystals, with β- or γ-form extended-chain lamellae as their substructures. Secondly, research on the controllable growth of unique hierarchical structures, composed of nano-structured micrometer-sized β- or γ-form crystalline domains, which were thought to be the basic physical structures of a super-hydrophobic surface with lotus effect, is to be conducted by the introduction of graphene into fluoropolymers at high pressure. This is expected to result in the preparation of such self-powered surface active materials with both piezoelectricity and special wettability for niche applications as controlled-release drug delivery systems and catalyst supports. Finally, investigation on the ternary composite systems, based on ionic polymers with sulphonic groups, fluoropolymers and graphene, is to be performed at high pressure. By optimizing the experimental conditions, fabrication and actuation of such electro-active polymer-based composite systems with high mechanical-to-electrical energy conversion efficiency are anticipated to be realized for the assembling of a new-generation of self-powered biomimetic actuators and sensors, achieved by the formation of β- or γ-form extended-chain crystallites of fluoropolymers in the ternary blends. The investigations in this project may open a new avenue for the design and mass processing of novel polymer-based smart nano-composites with self-reinforcement, which can diversify niche applications in self-powered wireless nanodevices and nanosystems.

基于偏氟乙烯基聚合物的压电系统的成功制备主要取决其中β或γ晶型的极化晶体的结构及含量。本项目研究二维纳米碳材料石墨烯原位诱导压电聚合物的高压自组装过程，实现多层次压电性凝聚态结构的有效调控，制备可从环境中搜集能量，以实现功率自给的自驱动复合材料体系。包括探索高压条件下石墨烯的存在对压电聚合物各种晶型转换的影响，掌握体系形态演化规律，分析所生成自组装压电聚合物纳米结构的形成机理，制备以β或γ伸直链晶体为亚结构的、从而表现出超强压电特性的系列聚合物纳米材料，及以微米与纳米结构相复合的的分级结构为特征的﹑兼具压电效应与特殊浸润性的表面活性材料，应用于自驱动药物缓释体系及催化剂载体等领域，进而引入磺酸离子聚合物制备具有优异机械-电能转换效率的三元复合物，用于新一代自驱动仿生致动器及传感器的组装。本研究拟解决应用于自驱动系统的新型聚合物材料在规模化加工中的关键问题，并为其设计和制备探索出一条新途径。

基于偏氟乙烯基聚合物的压电系统的成功制备主要取决其中β或γ晶型的极化晶体的结构及含量。本项目研究二维纳米碳材料石墨烯原位诱导压电聚合物的高压自组装过程，实现多层次压电性凝聚态结构的有效调控，制备出可从环境中搜集能量，以实现功率自给的系列自驱动复合材料体系，在新一代自驱动药物缓释体系、催化剂载体及仿生致动/传感器领域具有应用潜力。包括探索高压条件下石墨烯的存在对压电聚合物各种晶型转换的影响，掌握体系形态演化规律，分析所生成自组装压电聚合物纳米结构的形成机理，制备以β或γ伸直链晶体为亚结构的、从而表现出超强压电特性的系列聚合物纳米材料，及以微米与纳米结构相复合的的分级结构为特征的﹑兼具压电效应与特殊浸润性的表面活性材料，进而引入磺酸离子聚合物制备具有优异机械-电能转换效率的三元复合物。另外，设计并组装出基于新型自驱动压电聚合物杂化复合材料的系列微/纳米发电机, 材料自身通过高压结晶完成自极化过程，使得其无需特殊的高电压极化处理即可从工作环境中捕获不同频率及幅度的动态机械能，并将其高效率地转换为电能。特别是其中新概念免极化动态压电驻极体发电机在动态机械刺激下电压输出密度达到14.6伏特/平方厘米，超出绝大多数目前广泛应用与研究的代表性压电聚合物﹑压电复合材料及压电驻极体。本研究为应用于自驱动系统的新型压电聚合物复合材料在规模化加工中关键问题的解决做出贡献，并为其设计和制备探索出一条新途径。项目执行期间，发表国际刊物SCI收录论文13篇，其中9篇影响因子大于3.0，4篇影响因子大于7.0，最高影响因子16.658，同时发表国际/国内会议论文4篇，研究生学位论文6篇，出版英文著作1部。