The Study of Molecular Relaxation Using Dielectric Permittivity

在这个由化学系实验物理化学资助的项目中，Berberian教授(圣约瑟夫学院)将研究介电活性分子在与非极性、结构相似的物种的溶液中的旋转运动。介电常数的温度、频率和浓度依赖关系将被用来区分液态动态行为的相互竞争的模型。通过将测量扩展到低温，玻璃态的分子间力特征将被阐明。这项工作将在本科生助理的帮助下进行，他们将受益于接触到现代研究设备和方法。有些分子具有微小的电偶极矩。通过将这些分子溶解在大小和形状相似的电惰性物质的混合物中，并使溶液成为电路的一部分，就有可能利用电流的变化来研究分子周围环境如何影响其旋转运动。这一点很重要，因为在运动变得极其缓慢的低温下，缺乏对分子间力的详细了解。贝贝里安教授在这一领域的研究将使人们更好地理解这种“玻璃态”物质。

In this project funded by Experimental Physical Chemistry in the Chemistry Division, Prof. Berberian (St. Joseph's College) will study rotational motion of dielectrically active molecules in solution with non-polar, structurally similar species. The temperature, frequency, and concentration dependence of dielectric constant will be used to distinguish among competing models for liquid state dynamic behavior. By extending the measurements to low temperatures, intermolecular forces characteristic of the glassy state will be elucidated. The work is to be carried out with the aid of undergraduate assistants, who will benefit by exposure to modern research equipment and methodology. %%% Some molecules possess tiny electric dipole moments. By disolving such molecules in mixtures of electrically inert species of similar size and shape, and making the solution part of an electric circuit, it is possible to use variations in current to study how the surroundings of a molecule influence its rotational motion. This is important because at low temperatures where the motion becomes extremely sluggish, detailed understanding of the intermolecular forces is absent. Prof. Beberian's project in this area will lead to an improved undertanding of this "glassy" state of matter.