高温处理对螺旋炭纤维微观拓扑结构的影响

Effect of high temperature treatment on the topological microstructure of micro-coil carbon fibers

对高温处理前后螺旋炭纤维的微观拓扑结构进行了探究与表征,结果表明,制备态螺旋炭纤维具有类似年轮状结构的近圆形横截面,在纵截面上体现为近似鲱鱼骨结构,其石墨微晶尺寸小、取向度差;高温处理后,其三维结构可理想地看作是由石墨微晶以具有锥角的多面柱体形式沿螺旋方向堆叠而成,表观上炭纤维显示为尺寸均匀的多面柱体形貌。X射线衍射和Raman散射结果从宏观量级上证明了样品微观尺度有序度得到提高。为基于结构的性能预测和应用设计提供了可靠的参考。

The topological microstructure of micro-coiled carbon fibers （MCFs） before and after high tempera- ture treatment （HTT） was explored and characterized. Results suggested that as-grown MCFs had an annular ring-like structure in the cross section and a herringbone-like structure in the longitudinal section, but the orienta- tion range of graphitic domains was wide. After HTT, the coiled fibers consisted of stacked pyramidal prisms of ordered graphitic domains. The apparent morphology of the coiled fibers is a uniform spiral prism. The evolve- ment of the microstructure of MCFs after HTT was also confirmed by X-ray diffraction and Raman spectroscopy. The topological microstructure provides a reliable reference for the prediction of properties and projected applica- tions of the MCFs.