离子液体[Emim]Br水溶液的比热容测量及其模型化

Determination of the heat capacity of aqueous solutions of [Emim]Br

在温度为298～343K，质量分数为10％～90％的条件下，使用BT2．15型Calvet微量量热仪测定了离子液体[Emim]Br水溶液的定压比热容数据，并建立了体系的比热容与温度和浓度的经验关联式，拟合的平均偏差为0．42％。通过比热容实验数据，计算了溶液体系的超额摩尔比热容，发现相对于理想溶液呈正偏差，并随着浓度和温度的增加而增大。

The heat capacities of the ionic liquid [ Emim] Br （ 1-ethyl-3-methylimidazolium bromide） and its aqueous solutions with concentrations of 10% - 90% have been measured in the temperature range 298 K to 343 K using a Calvet microcalorimeter. An equation for the dependence of the heat capacity on temperature and concentration was derived. The average deviation between the values given by this equation and the experimental values was O. 42%. Based on the experimental data, the excess molar heat capacities （c p^E） for the [ Emim ] Br aqueous solutions were calculated, and positive values were observed over the mole fraction range studied. The values of cp^E were found to increase with increasing mole fraction and temperature.