Harvey Allan H, Mountain Raymond D
Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, 303-497-3555.
Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899.
Int J Thermophys. 2017 Oct;38. doi: 10.1007/s10765-017-2279-6. Epub 2017 Aug 16.
A new method is developed for correlating the static dielectric constant of polar fluids over wide ranges of conditions where few experimental data exist. Molecular dynamics simulations are used to establish the temperature and density dependence of the Kirkwood -factor, and also the functional form for the increase of the effective dipole moment with density. Most parameters in the model are obtained entirely from simulation; a single proportionality constant is adjusted to obtain agreement with the limited experimental data. The method is applied to hydrogen sulfide (HS) and sulfur dioxide (SO), both of which are important in geochemistry but have only a few dielectric data available. The resulting correlations agree well with the available liquid data, obey physical boundary conditions at low density and at high temperature, and interpolate in density and temperature in a physically reasonable manner. In addition, we present a more conventional correlation for the dielectric constant of sulfur hexafluoride, SF, where more data are available.
开发了一种新方法，用于关联极性流体在几乎没有实验数据的广泛条件范围内的静态介电常数。分子动力学模拟用于确定柯克伍德因子的温度和密度依赖性，以及有效偶极矩随密度增加的函数形式。模型中的大多数参数完全从模拟中获得；调整一个比例常数以与有限的实验数据达成一致。该方法应用于硫化氢（HS）和二氧化硫（SO），这两种物质在地球化学中都很重要，但仅有少量介电数据可用。所得的关联式与现有的液体数据吻合良好，在低密度和高温下符合物理边界条件，并以物理上合理的方式在密度和温度之间进行插值。此外，对于有更多数据可用的六氟化硫（SF）的介电常数，我们给出了一种更传统的关联式。
