快速压致凝固法制备两种非晶硫及其结构研究

发布时间：2018-02-27 23:12

本文关键词： 非晶硫液态硫λ转变放热熔化长条形压砧　出处：《西南交通大学》2016年硕士论文　论文类型：学位论文

【摘要】：本论文包含两部分研究内容,第一部分是采用快速增压法将λ转变前后的液态硫快压凝固为两种非晶硫。两种非晶硫表现出不同的颜色和透明度,与λ转变前后液态硫的颜色变化对应,因此我们推测这两种非晶硫包含λ转变的信息。对非晶硫样品进行了拉曼散射光谱分析、差示扫描量热分析及X射线衍射分析等,结果表明：即使是从TTλ的条件下凝固下来得到的非晶硫中也存在着较大体积分数的聚合链。通过比较不同的压力温度条件下制备的非晶硫中聚合链的含量,发现提高增压幅度及增压速率比提高液态硫的温度可以获得更高的聚合链含量。热分析的结果表明两种非晶硫都具有高热稳定性,在10K/min的升温速率下可以避免晶化直接转变为液态硫,并且都是反常放热熔化。综上,我们推测聚合链是快速增压过程中形成的,并且是否含有聚合链并不是引起两种非晶硫颜色及透明性差别的原因。本论文的第二部分内容是对长条形压砧进行压力标定及压力分布均匀性进行研究。针对圆形端面平面对顶压砧装置中压力梯度大的问题,本课题组洪时明教授设计了一种长条形端面的平面对顶压砧,并且推测这种压砧可在沿压砧中心线的狭长区域内产生均匀分布的高压力。实验结果表明：长条形端面(长20mm、宽5mm)的硬质合金对顶压砧装置可产生10GPa以上的高压,沿长条形中心线上至少12mm长度范围内压力分布是均匀的,在2.55GPa压力时测量偏差小于2.0%,在7.7GPa时测量偏差小于3.6%。长条形平面对顶压砧的压力分布特点非常有利于对长条形样品进行高压物性测量。
[Abstract]:In the first part, the liquid sulfur before and after 位 transition is solidified into two kinds of amorphous sulfur by rapid pressurization method. The two kinds of amorphous sulfur show different color and transparency. In accordance with the color change of liquid sulfur before and after 位 transition, we speculate that these two kinds of amorphous sulfur contain the information of 位 transition. Raman scattering spectroscopy, differential scanning calorimetry and X-ray diffraction analysis of amorphous sulfur samples are carried out. The results show that even the amorphous sulfur obtained from the solidification of TT 位 has a large volume fraction of the polymeric chain. The content of the polymeric chain in the amorphous sulfur prepared at different pressure and temperature is compared. It is found that the higher polymerization chain content can be obtained by increasing the pressure amplitude and the pressurization rate than by increasing the temperature of liquid sulfur. The results of thermal analysis show that both kinds of amorphous sulfur have high thermal stability. At a heating rate of 10 K / min, crystallization can be avoided directly into liquid sulfur, and both are anomalous exothermic melting. In summary, we speculate that the polymerization chain is formed during the rapid pressurization process. And the existence of polymeric chains is not the cause of the difference in color and transparency between the two kinds of amorphous sulfur. The second part of this thesis is to study the pressure calibration and pressure distribution uniformity of the long strip anvil. The problem of large pressure gradient in the device of face plane to top anvil, Professor Hong Shiming, our research group, has designed a plane-to-top anvil with long stripe end face. It is inferred that this anvil can produce high pressure distributed uniformly in the narrow and narrow region along the center of the anvil. The experimental results show that the high pressure over 10GPa can be generated by the cemented carbide anvil with long strip end face (20mm in length and 5mm in width). The pressure distribution is uniform in the length range of at least 12mm along the long strip centerline, The measurement deviation is less than 2.0 at 2.55 GPA and less than 3.6 at 7.7 GPA. The pressure distribution characteristics of the long plane-to-top anvil are very favorable for the measurement of the high pressure physical properties of the long strip sample.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O613.51

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