在超冷的d-lyxose水溶液中,玻璃过渡现象和介电松
1Department of Physics, Madanapalle Institute of Technology & Science, Madanapalle, 517325, Andhra Pradesh, India.
Carbohydrate research
|August 12, 2023
概括
本研究使用热量计和光谱学研究d-lyxose水性混合物. 水集群在临界度以上的动态中占主导地位,支持纯水的玻璃过渡.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 生物物理学的生物物理.
背景情况:
- 了解水溶液中的糖的行为对于各种科学领域至关重要.
- 水的玻璃过渡温度 (Tg) 是正在进行的研究和辩论的主题.
- 研究糖水相互作用为复杂的流体动力学提供了洞察力.
研究的目的:
- 分析d-lyxose水性混合物中的动态过程,在各种温度和水合水平范围内.
- 阐明水分子的作用及其与d-lyxose矩阵的相互作用.
- 确定影响放松动态的临界水度,并估计纯水的玻璃过渡温度.
主要方法:
- 差分扫描热量计 (DSC) 用于测量热性质.
- 宽带介电光谱 (BDS) 探测分子动力学.
- 在150-300 K的温度下分析放松时间和介电强度.
主要成果:
- 在d-lyxose水性混合物中观察到两种不同的放松过程 (初级和水分子放松).
- 在玻璃过渡温度 (Tg) 下,水分子放松 (过程-II) 显示幅度增加,水在临界度 (xc = 0.28) 以上占主导地位.
- 纯水的估计玻璃过渡温度 (Tg) 为128±5.8K,与现有的文献相一致.
结论:
- 在d-lysose混合物中的水分子动力学受到水集群形成在临界度以上的显著影响.
- 该d-lyxose矩阵与水分子展现合作相互作用,与其他糖水系统相比,临界水含量略高.
- 该研究提供了进一步的证据,支持对纯水玻璃化过渡温度的公认值.
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