【作者】 赵北京；

【导师】 刘福生；

【作者基本信息】 西南交通大学 ， 凝聚态物理， 2013， 硕士

【摘要】 对于含能材料在高温高压状态的性质以及微观结构的变化一直受到人们的广泛关注。但是由于其自身的一些特殊性和实验技术方面的限制,使得科研工作者对该类材料的研究一直没有取得多大的进展。因此,研究者试图从某种与该类物质结构比较类似的物质出发,希望能对该类材料的研究提供一定的借鉴作用。有机物苯,作为最简单、典型的芳香烃化合物,对它在高温高压状态的各种性质及其分子微观结构的变化成为人们研究的热点。但是,由于受到实验技术的限制,对它的研究只能停留在宏观性质方面,在微观结构变化问题上未取得突破。本文利用二级轻气炮加载装置结合瞬态激光拉曼测试技术对液态苯在冲击压缩状态的拉曼光谱进行实时在线观测,通过观测C-C伸缩振动(992cm-1)和C-H伸缩振动(3061cm-1)所对应特征峰在峰形和峰位上的变化,对液态苯在冲击压缩过程中的结构失稳问题给出直接证据。本文通过优化靶结构、改变触发方式以及改进散射光收集系统,成功实现了与二级轻气炮相结合的动态拉曼测试系统。并利用该系统对液态苯在7-21GPa压力范围的拉曼光谱进行实时在线观测。实验结果表明,在13GPa以内,拉曼频移随压力的变化线性增加,频移量与分子振动模式有密切关系。首次利用光谱技术澄清了液态苯在13GPa附近的结构变化问题,并对冲击诱导液态苯分子结构的变化机理做出了解释。通过对光谱信号的分析,提出苯在冲击压缩过程中的结构失稳可以分为两个阶段：首先是C-H键断裂(13GPa),接着是C-C键断裂(19GPa)。对于新物质成分做了预测,从实验结果推测,生成物应该是结构类似于石墨的某种碳团簇,而且该物质是不透明的。液态苯的冲击诱导结构变化应该是由压力、温度共同决定的。更多还原

【Abstract】 The properties and structural transformation of the energetic materials under high temperature and high pressure condition have received extensive attention of people. However, because of some of its own particularities and restrictions in terms of the experimental technology, there are no great progress have been made in the study of these materials for the study of scientific researchers. Therefore, the researchers try to find a kind of substance with a similar structure with energetic materials, hoping to provide certain reference for study of these materials. Benzene as organic compounds, with the most simple, typical structure in aromatic hydrocarbon compounds, so the various properties and molecular microstructure changes under high temperature and high pressure have been researched extensively. But, due to the limitation of experimental technology, only the macroscopic properties were obtained, without a breakthrough on the microstructure change. This paper, the Raman spectra for liquid benzene in a state of shock compression have been observed online by using the two-stage light gas-gun loading device with transient laser Raman test technology, a directed evidence was given for the problem about structural stability of benzene in shock compression experiment through observing the changes in peak shape and peak position for C-C stretching vibration mode(992cm-1) and C-H stretching vibration mode(3061cm-1).Based on the optimization of the structure of target, change the way of trigger and improve scattered light collecting system, we successfully realized the combination of two-stage light gas-gun with Raman testing system. And observed Raman spectroscopy online for liquid benzene in the range of7-21GPa using the system. The experimental results show that within the13GPa, Raman frequency shift linearly increased along with the change of pressure, and the magnitude of frequency shift is closely depend on molecular vibration modes. Besides, firstly clarified the structural changes of liquid benzene around13GPa using Raman spectrum technology, and explained the mechanism about the impact induced molecular structural changes of benzene liquid. Through the analysis of spectral signal, put forward the structure instability of benzene in the shock compression process can be divided into two stages: the first is rupture of C-H bond(13GPa), then is C-C bond(19GPa). Do the forecast for the composition of new material, from the experimental results we speculated that the products are a certain kind of carbon clusters which is similar to graphite, and the material is not transparent. The impact induced structural change of liquid benzene should be decided together by pressure and temperature.更多还原