以C3H6(丙烯)+H2,MTS+H2,CH4+BCl3+H2,C3H6(丙烯)+BCl3+H2为先驱体,采用量子力学结合统计热力学、变分过渡态理论和反应动力学等方法,研究制备典型陶瓷(C,SiC和BxC)的化学反应机理。重点阐述用精确量子化学方法获取可能中间体、过渡态的结构与热化学数据、用化学势极小原理确定复杂体系化学平衡规律,以及确定化学反应通道、最佳反应途径、速率常数和反应动力学规律等。为这些陶瓷材料应用于层状碳、抗氧化SiC以及自愈合BxC陶瓷的成分控制和工艺优化提供科学基础的同时,本文也指出理论方法中的不足和改进方向。
The chemical reaction mechanism of preparing typical ceramics(C,SiC and BxC)was studied,using C3H6(propylene)+H2,MTS+H2+Ar,CH4+BCl3+H2,and C3H6(propylene)+BCl3+H2as precursors,and based on the quantum mechanics combined with statistical thermodynamics,variational transition state theory and chemical reaction kinetics.The thermochemistry data are predicted in a prescript high accuracy.The process is to determine as many as possible the reaction intermediates and transition states,to develop their thermochemistry data,to examine the reaction thermodynamics properties of the reaction system,to identify the possible reaction pathways,to evaluate the rate constants of the most favorable paths,and to explore the reaction rates.These researches are scientifically instructive to the composition control and processing optimization for layered carbon,antioxidation SiC and self-healing BxC.Problems concerning the theoretical methods are also proposed to be further studied.