碳化硅纳米线表面改性及增强复合材料的研究

A novel strategy, for the first time, is proposed in this project to solve the difficulties of dispersion and interface combination between SiC nanowires and the matrix when SiC nanowires are used as the reinforcement in composites. It is carried out through the functional surface modification of SiC nanowires. Firstly, SiC nanowires are synthesized via high gas pressure annealing technique. And SiC nanowires are self-assembled into non-woven fabrics by optimization of process parameters. Secondly, SiC nanowires are annealed in air to form the core-shell structure of SiC@SiO2. Then, organo-functional groups are decorated on the surface of SiO2 by chemical modification method so that so that the SiC nanowires have good wetting and dispersion in the matrix of epoxy resin. Finally, the modified SiC nanowires are used as reinforcement to prepare the epoxy resin matrix composites in order to investigate the dispersion and interfacial bonding of modified SiC nanowires in epoxy resin. It is hoped to improve nanowire reinforcing and toughening, thus improving the mechanical properties of the composites. This project can provide fundamental data for SiC nanowires in the field of resin matrix composites reinforced applications, which will prompt the practical application of SiC nanowires.

本项目拟采用"SiC纳米线表面功能化修饰改性"的新思路，解决SiC纳米线作为树脂基复合材料增强体使用过程中的分散与界面结合问题。首先，采用高压气氛热处理工艺制备出SiC纳米线，优化工艺使SiC纳米线自组装成纳米无纺布。接着，通过空气热处理工艺在SiC纳米线表面反应生成一层SiO2膜，形成具有SiC@SiO2核壳结构的复合纳米线。然后，采用化学表面修饰的方法，在SiC纳米线外围的SiO2膜表面上修饰特定的官能基团，使SiC纳米线在树脂中具有较好的润湿性和分散性。最后，将表面改性后的SiC纳米线用于增强环氧树脂复合材料，考察纳米线在环氧树脂中的分散性和界面结合情况，从而制备出力学性能优异的复合材料。本项目着重研究SiC纳米线的表面改性及其增强复合材料的机理，项目的实施和完成将为SiC纳米线在复合材料增强领域的应用提供理论基础与技术支撑，从而进一步推动SiC纳米线的实质性应用。

本项目针对 SiC 纳米线在增强树脂基复合材料领域所遇到的分散与界面结合问题，通过热氧化法让SiC纳米线生成一层SiO2包覆层，重点研究SiO2包覆层的可控生长与机理，调控SiO2包覆层的形貌与厚度，使其在树脂中更容易润湿、分散、形成良好的界面结合，从而实现对树脂基复合材料起到良好的增强增韧效果。本项目的实施，揭示了SiC纳米线表面氧化行为与演变规律，建立起SiC纳米线表面氧化改性模型，为SiC纳米线增强树脂基复合材料的发展提供实验和科学依据，同时也为SiC纳米线在功能材料领域的应用提供理论基础，从而推动SiC纳米线实质性应用的进程。