Development of measuring apparatus for thermophysical properties in a very small qyuantity of substances by means of ac calorimetric method

交流量热法微量物质热物性测量装置的研制

基本信息

批准号：
01850007
负责人：
HATTA Ichiro
金额：
$ 7.94万
依托单位：
Nagoya University, School of Engineering Grant-in-Aid for Developmetal Scientific Research (B) (2)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

A light-irradiation-type ac calorimeter has been developed for obtaining thermophysical properties in a small quantity of materials.One of the aims in the present study is to measure the heat capacity of a small quantity of liquid. The sample cell is made of a very fine stainless steel tube, for instance, 130mum in inside diameter, 17Omum in outside diameter and 39mm long, which is filled with 0.52mul of a liquid sample. To obtain the absolute value of the heat capacity, evaluation of the heat capacity of the empty cell and the amplitude of ac heat flux supplied to the cell is necessary. For this purpose, the amplitude of ac temperature of the empty cell, the cell filled with a standard liquid and the cell filled with a liquid sample. From them, the heat capacity per unit volume of the liquid sample is obtained. In this measurement, the absolute value of heat capacity in liquid sample is determined within an accuracy of 1%. Using this method, the heat capacity of phospholipids in aqueous suspension was measured. The heat capacity in dipalmitoylphosphatidylcboline (DPPC)-cholesterol with cholesterol, concentrations up to 7 mol%. The heat capacity in DPPC-dimyristoylphosphatidylicholine (DMPC) mixtures was measured with special attention to the condition for the appearance of metastable state, which appears in pure DPPC and does not appear in pure DMPC. It was found that the metastable state no longer appears at the DMPC concentrations more than 50 mol%.The measurement of thermal diffusivity or thermal conductivity is desirable to know the thermophysical properties of a small quantity of materials. A light-irradiation-type ac calorimetry was also applied to the measurement of thermal diffusivity in not only thin films but also fine wires.

已经开发出一种用于获得少量材料的热物理特性的光辐照型AC量热仪。本研究中的目标之一是测量少量液体的热容量。样品电池由一个非常细的不锈钢管制成，例如，内径为130mum，外径17omum，长39mm，填充有0.52mul的液体样品。为了获得热容量的绝对值，需要评估空细胞的热容量以及提供给电池的AC热通量的幅度。为此，空单元的交流温度幅度，填充有标准液体的细胞和填充液体样品的细胞。从他们那里获得了每单位体积的热容量，获得了液体样品的热量。在此测量中，液体样品中热容量的绝对值在精度1％的范围内确定。使用这种方法，测量了水性悬浮液中磷脂的热容量。二硫二酰磷脂酰纤维胺（DPPC）胆固醇的热容量，胆固醇的浓度高达7 mol％。测量了DPPC-Dimyristoylphospadidylicholine（DMPC）混合物中的热容量，并特别注意亚稳态的出现条件，该状态以纯DPPC出现，并且不显示在纯DMPC中。发现亚稳态不再以DMPC浓度超过50 mol％出现。需要了解少量材料的热物理特性的热扩散率或热导率的测量。光辐射型AC量热法也用于测量不仅薄膜，而且还使用细丝中的热扩散率。