统一玻璃制造器的温度依赖的动态
Joseph B Schlenoff1, Khalil Akkaoui1
1Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, Florida 32306-4390, USA.
The Journal of chemical physics
|July 15, 2024
概括
研究人员使用过渡状态理论 (TST) 解释了无形材料中的原子重新排列如何导致在玻璃过渡温度 (Tg) 附近的散装性质变化. 这为了解玻璃形成器及其放松动态提供了一个统一的框架.
科学领域:
- 材料科学 材料科学 材料科学
- 化学物理 化学物理
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 无形材料在它们的玻璃过渡温度 (Tg) 附近显示大量性质的显著变化,例如模量和粘度.
- 这些宏观性质变化的微观起源一直是材料科学的长期挑战.
- 了解这些转变对于设计具有特定热和机械性能的材料至关重要.
研究的目的:
- 阐明在局部放松演变为Tg以上宏观结构放松的基础上的原子/分子机制.
- 根据重新排列单位的数量,制定玻璃成型器的系统分类.
- 提供适用于各种玻璃系统的统一理论框架.
主要方法:
- 过渡状态理论 (TST) 的应用,以分析无形材料中的原子/分子运动.
- 单位运动分为两个群体的分类:nα单位的同时重新排列和原始生命周期内非同时的重新排列t1.1.
- 从各种各样的玻璃材料和具有玻璃反应的材料中分析文献数据.
主要成果:
- 确定了关键数量的重新排列单元 (nα = 1-4) 系统地分类玻璃形成器和与脆弱性相关.
- 证明 Johari-Goldstein 的β-放松源于 nα 单位的声.
- 开发了一个四个参数方程,可以准确地适应强弱玻璃形成器在广泛的温度范围内.
- 将模型的适用性扩展到离子输送聚合物和铁电松散器.
结论:
- TST方法成功地弥合了无形材料中微观单元放松和宏观性质变化之间的差距.
- 拟议的分类和方程为各种材料的玻璃过渡现象提供了统一的理解.
- 该研究强调了激活在明显的预指数因子中的重要作用,并说明了-补偿.
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