基于量子化学的化学交换法分离硅同位素反应机理及工业应用基础研究

Isotopically pure silicon material is becoming a global trend in the development of new semiconductor material. It has long been the hot and difficult research subject both in theoretical and industrial fields to improve the efficiency of silicon isotope separation, and so as to achieve industrial production. A research method combining quantum chemical calculation and laboratory experiments is adopted, the reaction mechanism of main reactions is inferred through the molecular structural and energy parameters of the reactants and products involved in the process of chemical exchange, which are obtained from quantum chemical calculation based on density functional theory(DFT), and the theoretical calculation method of silicon isotope separation factor is proposed according to the structural parameters and the partition function. Furthermore, the project will keep verifying and optimizing the inferred reaction mechanism and the proposed theoretical calculation method with laboratory experiments of complexation, single-stage chemical exchange and decomposition. After comparing the complexity of different reaction processes on the basis of the reaction mechanism and separation factor calculated values, the most suitable industrial separation system will be identified. A large quantify of complete, comparable fundamental data related to the reactions are to be obtained through experimental study on this separation system, which will constitute the industrial design foundation of chemical exchange process for silicon isotope separation. Therefore, the study is of both theoretical significance and application value.

同位素纯硅材料正成为世界半导体材料发展的新方向，提高硅同位素的分离效率并实现工业化生产一直是该领域理论和生产应用研究的热点与难点。项目将采用量子化学计算与实验相结合的研究方法，通过对化学交换法分离硅同位素过程涉及的反应物和产物的分子结构、能量等参数进行基于密度泛函（DFT）的量化计算，推定主要反应的反应机理，根据结构参数和配分函数，提出硅同位素分离系数的理论计算方法，再通过络合、单级化学交换与裂解三个主要反应的实验研究,对所推定的反应机理和所提出的分离系数理论计算方法加以反复验证与不断优化。利用该反应机理与分离系数计算值，对比反应进行的难易程度，找出最适用于工业化的分离体系。通过对该分离体系的实验研究获得一套数量完整、数值可比的反应相关基础数据，为化学交换法分离硅同位素的工业化设计提供依据，该项研究具有重要的理论意义与实际应用价值。

同位素纯硅材料正成为世界半导体材料发展的新方向，提高硅同位素的分离效率并实现工业化生产一直是该领域理论和生产应用研究的热点与难点。项目基于量子化学计算方法，计算了SiF4与甲醇、乙醇、丙醇、异丙醇、正丁醇、异丁醇、正戊醇、2-戊醇、3-戊醇、正己醇、正庚醇、正辛醇等络合剂组成的分离体系用于分离28Si、29Si、30Si三种硅同位素过程所涉及到的络合、化学交换、裂解反应的反应物及产物的分子结构、能量等参数，提出硅同位素分离系数的理论计算方法，搜寻得到了各体系化学交换反应的过渡态结构，分析了反应机理，对化学交换法分离硅同位素的过程进行了初步的实验和模拟计算研究，并对其工业化生产过程进行了初步的设计，为实现硅同位素分离的工业化提供依据。