离子化富勒烯衍生物热致液晶的构筑、形成机理及光电性能研究

It is a big issue for both chemists and material scientists to construct fullerene (C60)-based thermotropic liquid crystals with high conductivity and carrier mobility for their potential applications in optoelectronics. Here, novel C60 derivatives functionalized with both ionic moieties and mesogens will be synthesized according to cycloaddition reactions. Based on the evaluation of their thermal stability, thermotropic behavior and fine microstructures, new building blocks for thermotropic liquid crystals, i.e., ionic C60 derivatives, will be screened. Influences of the ionic moieties and mesogens on the physicochemical properties and the microstructures of the liquid crystals will be analysed, from which the formation mechanism of the liquid crystals will be deduced. The optoelectronic properties of the liquid crystals will be deeply investigated and the mutual feedback between the ionic moiety, mesogen and the optoelectronic properties of the liquid crystals will be explored. The dependence of the conductivity and carrier mobility on the fine microstructure of the liquid crystals will be revealed. Finally, means to optimize the solar cell performance will be summarized and thermotropic liquid crystals with high stability, high conductivity and high carrier mobility will be sorted out.. The purpose of this project is to deepen the investigation of the construction, formation mechanism and optoelectronic properties of fullerene (C60)-based thermotropic liquid crystals, and to provide ideal materials and solid theories for their practical applications in optoelectronics.

构筑高电导率、高载流子迁移率的富勒烯(C60)热致液晶，以发挥其在光电领域中的巨大应用潜力，是化学、材料学家共同面对的重大课题。本项目基于环加成反应，制备离子化基团、介晶共修饰的C60衍生物；考察其热稳定性、热致相变行为和精细微观结构，挑选和构筑能表现热致液晶行为的新基元-离子化C60衍生物；继而分析离子化基团和介晶对液晶物理化学性质及微观结构的影响规律，阐明液晶的形成机理；深入考察液晶体系的光电性能，探讨离子化基团、介晶与光电性能之间的互馈机制，揭示液晶电传导性能和载流子迁移率与其精细微观结构的依存关系，归纳优化液晶光电性能的方法并筛选出一批具有高稳定性、高电导率和载流子迁移率的热致液晶体系。. 本项目旨在拓宽、深化C60衍生物热致液晶体系的构筑、形成机理及光电性能研究，为其在光电领域的实际应用提供材料支持和理论指导。

研究工作紧紧围绕项目主体方向，以富勒烯C60（以下简称C60）的功能化为重点，以与之结构类似的碳量子点、碳纳米管、石墨烯、构成碳纳米材料的片段（如两个苯环组成的萘环）及各类复合材料为补充，设计、制备了一系列新颖的碳纳米材料和复合材料体系，主要包括：1）选用[3+2]环加成反应，通过优化中间体即取代苯甲醛的结构，将多金属氧酸盐、金刚烷等接入富勒烯C60，制备了刚性基团修饰的1:1和2:1型C60衍生物；2）制备了氮氧自由基标记的、具有自旋活性的C60衍生物，并将其嵌入尺寸和构型完全不同的两种金属有机骨架多孔材料中，构筑了C60/MOFs复合材料体系；3）将C60引入无盐阴/阳离子表面活性剂水溶液中形成的层状溶致液晶，构筑了C60/溶致液晶复合材料体系；4）通过逐次修饰的策略，制备了C60-氧化石墨烯复合材料体系；5）利用纳米纤维素的模板效应，构筑了掺杂氧化碳纳米管的手性向列相薄膜；6）利用树枝状烷基小分子的分散、稳定作用，由石墨粉通过简单超声的方法，制备了稳定性良好的石墨烯有机分散液；7）利用混酸回流、一步热解等方法，制备了一系列结构和发光波段各异的碳量子点。. 在上述工作的基础上，详细考察了结构确定的各类C60衍生物溶液中和无溶剂条件下的超分子自组装结构，对分子及其自组装体的光谱特性、得-失电子能力和磁性等进行了详细研究；以含C60复合材料体系作为对电极，或以原位修饰的TiO2/碳量子点为光阳极，考察了各复合体系在有机太阳能电池中的应用；利用C60的光动力特性和氧化石墨烯的光热特性，考察了该复合体系的光动力-光热联合治疗效果；考察了烷基修饰C60/石蜡油体系及C60/溶致液晶体系的减摩抗磨效果。