Vitrification, Viscous Liquids and the Glass Transition in the Very High Positive Pressure Regimes

奥斯汀·安吉尔教授、乔治·H·沃尔夫教授、斯图尔特·M·林赛教授和威廉·F·奥利弗博士得到了理论和计算化学计划的资助，他们研究玻璃化、粘性液体和在超高压条件下的玻璃化转变。这项研究将阐明各种重要的化学体系和材料在极端压力条件下的行为。这项研究的主要目的是将液态和玻璃化转变现象的研究扩展到10 Gpa的超高压区域，在该区域，压力和体积的乘积与分子间势相当。将使用多种实验技术来确定这种系统的特征，包括使用超高对比度布里渊散射和使用钻石顶压室来保持样品在超高压下。该提案的一个次要目的是探索通过使晶格不稳定来使用压力诱导的玻璃化。安吉尔和他的同事推测，压力诱导的玻璃化现象是一种旋节崩塌，原则上类似于在极端负压下终止液体状态的现象。

Professors C. Austin Angell, George H. Wolf, Stuart M. Lindsay, and Dr. William F. Oliver are supported by a grant from the Theoretical and Computational Chemistry Program to study vitrification, viscous liquids, and the glass transition in the very high pressure regime. This research will elucidate the behavior of a variety of important chemical systems and materials when subjected to conditions of extreme pressure. The main thrust of this research concerns the extension of the study of liquid states and glass transition phenomenology to the very high pressure regime of 10 GPa where the product of the pressure and volume are comparable to the intermolecular potential. A combination of experimental techniques will be used to characterize such systems including the use of ultra-high contrast Brillouin scattering in conjunction with the use of a diamond anvil cell to maintain samples at ultra high pressures. A subsidiary thrust of the proposal is to explore the use of pressure-induced vitrification by destabilization of crystal lattices. Angell and co-workers conjecture that the pressure-induced vitrification phenomenon is a spinodal collapse similar in principle to that which terminates the liquid state at extreme negative pressures.