Calorimetric Study on Structural Relaxation of Molecular Ground

首次研制了顶置式绝热量热计。从空电池和苯甲酸的测试实验中三-OMICRON-甲基-β-环糊精（TMCD）、蔗糖（SUC）、水杨苷（SAL）、酚酞（PP）、1，3，5-三-α-萘基苯（TNB）、对-四联苯（p-QP）、采用振动磨研磨对三联苯（p-TP）和1，3，5-三苯基苯（TPB），并通过X射线粉末衍射（XRD）和差热分析（DSC）研究了它们的机械研磨非晶化能力。用绝热量热计测量了TMCD和TNB的研磨非晶固体（GAS）和液体淬火玻璃（LQG）在5 ~ 380 K温度范围内的热容，发现两种样品的GAS比LQG具有更大的构型焓，表明分子GAS具有大的取向无序、局部应变用TMCD研究了非晶化过程中热焓弛豫随时间和温度的变化规律，发现非晶化过程和热焓获得过程不仅与非晶化过程中的自由能有关，而且与非晶化过程中的热焓获得过程有关。液体和晶体之间的能量差和结构弛豫时间，以及晶体和非晶化固体的机械性能（例如塑性）。

A top-loating adiabatic calorimeter has been constructed for the first time. From the test experiments of an empty cell and benzoic acid (standard substance), the precision and accuracy of heat capacity were confirmed to be better that 0.1 % in the temperature region between 12 and 380 K.tri-OMICRON-methyl-beta-cyclodextrin (TMCD), sucrose (SUC), salicin (SAL), phenolphthalein (PP), 1,3,5-tri-alpha-naphthylbenzene (TNB), p-quaterphenyl (p-QP), p-terphenyl (p-TP) and 1,3,5-triphenylbenzene (TPB) were ground with a vibration mill and their abilities of mechanical milling amorphization were investigated by X-ray powder diffraction and differential thermal analysis. It was found that the ability of mechanical milling amorphization is strongly related to the glass forming ability.The heat capacities of the ground amorphous solids (GAS) and liquid-quenched glasses (LQG) of TMCD and TNB were measured with an adiabatic calorimeter in the temperature range between 5 and 380 K.It was found that GAS exhibits larger configurational enthalpy than LQG for both samples, suggesting that the molecular GAS has a structure with large orientational disorder, local strain, and defects.The grinding-time and grinding-temperature dependences of the enthalpy relaxation were investigated using TMCD.It was found that the amorphization process and enthalpy obtaining process are associated with not only the free-energy difference between the liquid and the crystal and the structural relaxation time but also the mechanical properties (e.g.plasticity) of the crystal and the amorphized solid.