基于界面设计的高强韧石墨烯仿生复合材料的构筑及增强增韧机理研究

Lightweight, ultra-strong and tough materials play a significant role in aerospace, military, biomedical and other fields. Rational design and optimization of the interfacial interactions between graphene and organic matrix is of importance for constructing bioinspired ultra-strong and tough graphene nanocomposites. Currently, the limitedly improved strength and toughness and unclear interfacial mechanism are the bottleneck hampering the development of this field. In this proposal, covalent bonding and coordination bonding are synergistically designed to be introduced into the interlayers of graphene materials. First, hydrazine derivatives are used to reduce graphene oxides and at the same time controllably graft organic groups on the surface of graphene under optimized conditions through forming covalent bonding in one step. After that, the phenolic hydroxyl groups in pyrocatechol derivatives could form coordination bonding with the metal ions. The influences of the bonding density and chain length on the mechanical properties of the obtained graphene nanocomposites are systematically studied. In this proposal, we would further theoretically study the strengthening and toughening mechanisms from the molecule level based on molecular dynamics, first-principles calculation, and “shear-lag” model and set up the relationships between structure and corresponding properties. This work would be promising to highly improve the strength and toughness, but also enrich our knowledge to understand the interfacial interactions in bioinspired graphene nanocomposites with high strength and toughness, so this work is scientifically meaningful.

轻质高强超韧功能材料在航天航空、军事、生物医学等领域具有重要作用。设计并优化石墨烯与有机基质间的界面效应是高强超韧石墨烯仿生材料制备领域的一个重要突破口。针对现阶段石墨烯基仿生复合材料强韧性能提高有限，界面作用机理不明晰等问题，本项目拟通过引入共价键和配位键界面协同作用，设计合成高强超韧石墨烯层状复合材料。首先运用水合肼衍生物实现一步还原氧化石墨烯，优化条件，在表面可控共价嫁接有机基团；然后通过邻苯二酚衍生物的二酚结构与金属离子形成配位化合键；研究不同价键比例、密度和链长对石墨烯强韧性质的影响。本项目还将进一步从理论上运用分子动力学，第一性原理计算和“剪滞”模型，从分子层面研究其增强增韧机理，并建立相应的构性关系。本项目的实施有望大幅度提高石墨烯仿生复合材料强韧特性，并将丰富石墨烯高强韧仿生复合材料的界面化学知识，具有重要的科学意义。

轻质高强超韧功能材料在航天航空、军事、生物医学等领域具有重要作用。设计并优化石墨烯与有机基质间的界面效应是高强超韧石墨烯仿生材料制备领域的一个重要突破口。针对现阶段石墨烯基仿生复合材料强韧性能提高有限，界面作用机理不明晰等问题，本项目拟通过引入共价键和配位键界面协同作用，设计合成高强超韧石墨烯层状复合材料。首先运用水合肼衍生物实现一步还原氧化石墨烯，优化条件，在表面可控共价嫁接有机基团；然后通过石墨烯上的羟基基团与羧基基团和壳聚糖上的氨基基团作用形成共价键，之后再与金属铁离子形成配位键。通过石墨烯仿生层状复合膜力学性能测试，理论推导增强增韧机制。本项目的实施有望大幅度提高石墨烯仿生复合材料强韧特性，并将丰富石墨烯高强韧仿生复合材料的界面化学知识，具有重要的科学意义。