Abstract In this work, thermal and mutual diffusivity of n-heptane (n-C7H16) with dissolved carbon dioxide (CO2) were simultaneously measured using dynamic light scattering (DLS) method from 298 to 473 K and saturation pressure up to 5.5 MPa. For this purpose, the DLS setup as well as temperature and pressure system were improved. Two hydrodynamic modes in connection with the statistical fluctuations of entropy and species were verified. The average expanded uncertainty of thermal and mutual diffusivity were 9.0 % and 4.9 % with a coverage factor of k = 2. The thermal and mutual diffusivity versus pressure under isothermal lines were briefly discussed and a comparison with literature was performed. The experimental thermal and mutual diffusivity measured in this work are in reasonable agreement with the literature data. This work is expected to provide fundamental data for engineering process.

中文翻译：

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动态光散射法测定正庚烷与溶解二氧化碳的热扩散系数和互扩散系数

摘要 在这项工作中，使用动态光散射 (DLS) 方法从 298 到 473 K 和高达 5.5 MPa 的饱和压力同时测量了正庚烷 (n-C7H16) 与溶解的二氧化碳 (CO2) 的热扩散率和互扩散率。为此，对 DLS 设置以及温度和压力系统进行了改进。验证了与熵和物种的统计波动有关的两种流体动力学模式。热扩散系数和互扩散系数的平均扩展不确定度分别为 9.0 % 和 4.9 %，覆盖系数为 k = 2。简要讨论了等温线下的热扩散系数和互扩散系数与压力的关系，并与文献进行了比较。在这项工作中测量的实验热和互扩散率与文献数据合理一致。