高压下的多醇:对弹性特性进行比较超声波研究
Elena L Gromnitskaya1, Igor V Danilov1, Vadim V Brazhkin1
1Vereshchagin Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, 108840 Moscow, Russia. grom@hppi.troitsk.ru.
这项研究研究了多醇,揭示了玻璃一般具有比晶体更低的弹性模块. 比醇 (n=6) 意外地呈现出跨州的最高弹性模量.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 声学 声学 在声学方面
背景情况:
- 多醇在各种应用中至关重要.
- 了解它们在不同状态 (晶体,玻璃) 中的弹性特性至关重要.
- 之前的研究还没有充分探索它们弹性特性的压力和温度依赖性.
研究的目的:
- 实验性地研究多醇 (甘油,红醇,利醇,利醇) 的超声波特性.
- 在晶体和玻璃状态下确定弹性特征的巴里克和温度依赖.
- 分析增加基对弹性特性和玻璃过渡行为的影响.
主要方法:
- 实验性的超声波研究.
- 同热压缩高达1 GPa.
- 从77K到295K的同位体加热.
- 弹性模块,散装模块,玻璃过渡温度 (Tg) 和脆弱系数 (m) 的分析.
主要成果:
- 所有研究的玻璃在相同的条件下,与其晶体对应物相比,都表现出较低的弹性模块.
- 在加热后在玻璃色红中观察到一连串的玻璃超冷液晶转换.
- 散装模块通常随着基组 (n=3-5) 的增加而减少,但比醇 (n=6) 显示出意想不到的高弹性模块.
- 玻璃过渡温度 (Tg) 和脆弱系数 (m) 倾向于随着基群数量的增加而增加.
结论:
- 基团的数量显著影响了多醇的弹性特性和玻璃过渡行为.
- 索尔比托的独特弹性行为需要进一步调查.
- 对于这些化合物来说,弹性模块在玻璃状状态下与晶状状态相比始终较低.
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