水的玻璃过渡,基于超灭实验
V Velikov1, S Borick, C A Angell
1Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
Science (New York, N.Y.)
|December 18, 2001
概括
水的玻璃过渡温度 (Tg) 被修改为165K,解决了先前研究中的差异. 这一发现澄清了水的含量.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 热力学是一种热力学.
背景情况:
- 水的玻璃过渡温度 (Tg) 仍然是争论的主题,实验值相互矛盾.
- 过度灭的玻璃,包括水,在重新加热时表现出显著的度放松外热.
- 在玻璃杯中对度放松的标准分析通常涉及将外热温度以Tg.
研究的目的:
- 解决超水的玻璃过渡温度 (Tg) 周围的不确定性.
- 研究水的热量计行为,并将其与其他玻璃制造系统进行比较.
- 建立一个一致的框架,以了解水杯中的度放松.
主要方法:
- 差分扫描热量计 (DSC) 用于测量放松外热量.
- 通过将外热温度与玻璃过渡温度 (Tg) 进行缩放来分析热量计数据.
- 与其他已知的玻璃形成物和二进制溶液相比,对超水的行为进行了比较.
主要成果:
- 使用公认的136K的Tg,超水与其他玻璃相比表现出异常行为.
- 将Tg重新计算为165±5K恢复了正常的玻璃行为,使水与其他超系统保持一致.
- 这个修订的Tg与H2O,ZnCl2和BeF2在二进制溶液中的网络前系统相一致.
结论:
- 以前接受的136K的Tg对水来说可能是不正确的,导致对其玻璃过渡行为的误解.
- 修订后的Tg为165±5K,提供了对水的度放松的一致的理解,与其他玻璃成型材料相比.
- 这一修订后的值对于准确建模水生物分子相互作用和理解生物系统至关重要.
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