借助纳米碳管/微米颗粒杂化增强体实现长程可控界面及高强高韧聚合物基复合材料

How to efficiently take the advantages of nano/micro reinforcement to offset the shortcomings of the polymer matrix, accordingly obtaining the synchronously strengthened and toughened composites, is the key issue urgently needed to be solved in the development process of materials science. In this project, we propose one kind of multiscale hybrids which consist of soft-shell and hard-core and are synthesized by in-situ growing carbon nanotubes (CNTs) on the surface of micro reinforcement via chemical vapor deposition (CVD) method. Thanks to the nano/micro hybrid structure along with adequate post-treatments including CNT connection strengthening and surface functionalization, the three-dimensional interpenetrating networks will be constructed in the polymer matrix, which will undoubtedly boost the interfacial areas between the reinforcement and polymer matrix and effectively form the long/short range interfaces. The main objective is to simultaneously improve the mechanical strength and toughness of polymer composites. This hybrid structure is also beneficial to solve the problem of aggregation and entanglement of carbon nanotube fillers in the polymer matrix and the large addition amount of micron-sized particles for achieving required properties. Firstly, through reasonably adjusting processing parameters such as hybrid fabricating, sizing and surface modification, the relationships between these parameters and the hybrid morphologies, interfacial functionalities and mechanical properties will be systematically revealed. Secondly, combining experimental results with finite element simulation analysis method, the influence of nano/micro-hybrids structures on the synergistic optimization of both mechanical strength and toughness of composites will be deeply revealed. This project will therefore not only provide new strategies for the systematical adjustment of composites mechanical properties but also drive the further development and application of the polymer-based composites with both high strength and toughness.

如何有效地结合纳米微米增强填料与聚合物的优势，而得到高强高韧的复合材料是当前材料科学发展中亟待解决的难题。本项目拟在微米颗粒表面原位生长碳纳米管以形成 “软壳/硬核”多尺度杂化体，通过结合原位加固和界面改性实现多功能化的增强体，及其在聚合物基体中的三维互穿互连网络的构建；通过扩展和调控基体与微米颗粒之间的界面尺度和性能，形成长程/短程界面，实现对聚合物基体强度和韧性的协同调控；该杂化结构有利于同时解决碳纳米填料在聚合物中的聚集和缠结问题，与微米增强体添加量大等难题。通过合理调控制备、上浆及表面修饰等参数，系统揭示碳纳米管在微颗粒表面原位生长、加固及改性等工艺条件与微纳杂化结构形貌、界面功能性及力学性能的内在科学规律；结合实验与有限元计算，深入探究微纳杂化增强体对复合材料强度韧性协同增强机制。本项目不仅为复合材料力学性能综合调控提供新策略，更将推动新型高强高韧复合材料的发展与应用。

高性能的先进聚合物基复合材料以其优异的结构强度与低密度，可以被广泛应用于航空航天等极端环境中，收到了全球学者的广泛关注与研究。然而，如何实现复合材料在平衡加工特性与功能稳定性的前提下实现结构强度与断裂韧性的显著同步提升，目前仍缺乏系统的机理研究和有效的材料设计。本研究提出以微米颗粒表面原位生长/合成一微纳米线阵列以形成 “一维纳米线阵列-二维微米基板”的多尺度杂化体，结合原位加固和界面改性实现多功能化的增强体，在聚合物基体中构建了三维互穿互连网络；通过对界面的合理设计，对传统杂化结构纳米线阵列的脱落问题进行了改善，揭示了纳米管在微颗粒表面原位生长、加固及改性等工艺条件与微纳杂化结构形貌与界面功能性的调控规律。通过扩展和调控基体与微米颗粒之间的界面尺度和性能，形成长程/短程界面，实现对聚合物基体强度和韧性，以及功能特性的协同调控。本项目不仅有利于同时解决高长径比一维填料在聚合物中的聚集和缠结问题，也为复合材料力学性能综合调控提供新策略，推动了新型高强高韧复合材料的发展与应用。