Fundamental Studies on Texture and Property Control in Carbon Materials

1. 织构的形成与控制提出了基于晶向的碳材料微织构分类方法。通过将沥青与酚醛树脂或聚氯乙烯的混合物在压力下碳化，可以在很大范围内控制所得碳的光学结构和颗粒形态。沥青的流变参数与沥青的分子量密切相关，与炭黑颗粒混合后，沥青的流变参数发生了显著变化。碳材料在裂纹扩展过程中表现出明显的非线性。从能量学的角度分析了这种非线性断裂行为，建立了各种断裂参数的实验测定方法。裂纹扩展过程中的能量耗散主要是由微裂纹引起的，分析碳材料的断裂行为需要考虑非常大尺寸的过程区和过程区尾迹。微开裂与炭素材料中填料焦炭颗粒的大小、热处理温度等织构密切相关。电极反应采用不同热处理温度的各种碳纤维（气相纤维、中相纤维和聚丙烯腈纤维）在浓硫酸中作为电极。硫酸在碳纤维石墨层中的嵌入和脱嵌不仅与纤维的结晶度有关，还与纤维的显微结构有关；取向良好的织构有利于插层和去插层。

1. Formation and control of textureNew classification of microtexture in carbon materials based on crystallite orientation was proposed. By carbonizing the mixtures of pitch with phenol resin or polyvinylchloride under pressure, optical texture of the resultant carbons and particle morphology can be controlled in a wide range. Rheological parameters of pitches depend strongly on their molecular weight and change remarkably by mixing with carbon black particles.2. Fracture behaviourCarbon materials show remarkable non-linearity during crack propagation. This non-linear fracture behaviour is analyzed on the basis of energetics and the experimental determination technique of various fracture parameters was established. Energy dissipation during crack propagation is mainly due to microcracking, and very large size process zone and process zone wake has to be taken into account for the analysis of fracture behaviour of carbon materials. Microcracking depended strongly on texture and so on the heat-treatment temperature and size of filler coke particles in the carbon materials.3. Electrode reactionVarious carbon fibres ( vapor-grown, mesophasepitch based and PAN based fibres ) with various heat-treatment temperatures are used as electrode in concentric sulfuric acid. Intercalation and de-intercalation of sulfuric acid into graphite layers in the carbon fibres depended not only on the crystallinity of the fibre but also on the microtexture in the fibre; well-oriented texture being preferable for intercalation and de-intercalation.