High-pressure experiments as a novel perspective to study the molecular dynamics of glass-forming materials confined at the nanoscale.
High-pressure experiments as a novel perspective to study the molecular dynamics of glass-forming materials confined at the nanoscale.
复制标题
高压实验是研究纳米级玻璃形成材料分子动力学的新视角。
作者：
M. Tarnacka;M. Mierzwa;E. Kamińska;K. Kamiński;M. Paluch
在这里，我们报告了开创性的高压介电研究的动态模型货车的范德华玻璃形成液体双酚-A二缩水甘油醚（DGEBA）渗透到阳极氧化铝（AAO）模板的平均孔径，d = 150和d = 18 nm。有人发现，虽然结构弛豫过程的形状随限制而变化，但对于给定的孔径，在不同的热力学条件下，它保持恒定。因此，时间-温度-压力（TTP）规则满足大多数散装物质也服从空间限制的液体。我们还首次表明，在高压下，核心和界面流动性之间存在解耦。此外，有人指出，在压缩过程中，相对于本体DGEBA，分子的前级分的结构动力学变得系统地更短。核心材料的增强的结构动力学，以及界面和核心分子的玻璃化转变温度的变化的压力系数，已经在它们的自由体积/密度堆积相对于本体DGEBA的不同演变以及界面张力的变化的背景下进行了讨论，这可能导致在不同热力学条件下吸附到孔壁上的液体的润湿性增强。所进行的高压测量提供了新的视角来探索两种不同的效果，压缩和约束的组合，这可能是在玻璃化转变现象的研究和在纳米尺度下的软材料的行为的突破。
Herein, we report the pioneering high-pressure dielectric studies on the dynamics of a model van der Waals glass-forming liquid bisphenol-A diglycidyl ether (DGEBA) infiltrated into anodic aluminum oxide (AAO) templates of the mean pore sizes, d = 150 and d = 18 nm. It was found that although the shape of the structural relaxation process varies with the confinement, it remains constant under varying thermodynamic conditions for a given pore diameter. Consequently, the time-temperature-pressure (TTP) rule satisfied for the majority of bulk substances is also obeyed for the spatially restricted liquid. We have also shown for the first time that there is a decoupling between the core and interfacial mobility at elevated pressure. Moreover, it was noted that the structural dynamics of the former fraction of molecules becomes systematically shorter with respect to the bulk DGEBA during the compression. The enhanced structural dynamics of the core material, as well as the varying pressure coefficients of the glass transition temperature of the interfacial and core molecules, have been discussed in the context of a distinct evolution in their free volume/density packing with respect to the bulk DGEBA, and a change in the interfacial tension, which may lead to the enhanced wettability of the liquid adsorbed onto the pore walls under different thermodynamic conditions. The performed high-pressure measurements offer novel perspectives to explore the combination of two different effects, compression and confinement, which might be a breakthrough in the study of the glass transition phenomenon and the behavior of soft materials confined at the nanoscale.
影响因子：
5.5
作者：
Ronald P White;J. Lipson
通讯作者：
Ronald P White;J. Lipson
影响因子：
5.5
作者：
White, Ronald P.;Lipson, Jane E. G.
通讯作者：
Lipson, Jane E. G.