Air Quality Research Center, University of California at Davis, Davis, CA, United States.
J Phys Chem A. 2010 Nov 25;114(46):12216-30. doi: 10.1021/jp105191z. Epub 2010 Nov 2.
A semiempirical model is presented that predicts surface tensions (σ) of aqueous electrolyte solutions and their mixtures, for concentrations ranging from infinitely dilute solution to molten salt. The model requires, at most, only two temperature-dependent terms to represent surface tensions of either pure aqueous solutions, or aqueous or molten mixtures, over the entire composition range. A relationship was found for the coefficients of the equation σ = c(1) + c(2)T (where T (K) is temperature) for molten salts in terms of ion valency and radius, melting temperature, and salt molar volume. Hypothetical liquid surface tensions can thus be estimated for electrolytes for which there are no data, or which do not exist in molten form. Surface tensions of molten (single) salts, when extrapolated to normal temperatures, were found to be consistent with data for aqueous solutions. This allowed surface tensions of very concentrated, supersaturated, aqueous solutions to be estimated. The model has been applied to the following single electrolytes over the entire concentration range, using data for aqueous solutions over the temperature range 233-523 K, and extrapolated surface tensions of molten salts and pure liquid electrolytes: HCl, HNO(3), H(2)SO(4), NaCl, NaNO(3), Na(2)SO(4), NaHSO(4), Na(2)CO(3), NaHCO(3), NaOH, NH(4)Cl, NH(4)NO(3), (NH(4))(2)SO(4), NH(4)HCO(3), NH(4)OH, KCl, KNO(3), K(2)SO(4), K(2)CO(3), KHCO(3), KOH, CaCl(2), Ca(NO(3))(2), MgCl(2), Mg(NO(3))(2), and MgSO(4). The average absolute percentage error between calculated and experimental surface tensions is 0.80% (for 2389 data points). The model extrapolates smoothly to temperatures as low as 150 K. Also, the model successfully predicts surface tensions of ternary aqueous mixtures; the effect of salt-salt interactions in these calculations was explored.
提出了一个半经验模型，用于预测从无限稀释溶液到熔融盐的浓度范围内的水溶液和其混合物的表面张力（σ）。该模型最多只需要两个与温度有关的项，就可以表示纯水溶液、水溶液或熔融混合物的表面张力，涵盖整个组成范围。发现熔融盐的方程σ=c(1)+c(2)T（其中 T（K）为温度）中的系数与离子价和半径、熔点和盐摩尔体积有关。因此，可以估算出没有数据或不存在熔融形式的电解质的假想液体表面张力。当外推到正常温度时，熔融（单一）盐的表面张力与水溶液的数据一致。这使得可以估计非常浓、过饱和的水溶液的表面张力。该模型已应用于整个浓度范围内的以下单一电解质，使用了 233-523 K 温度范围内的水溶液数据，以及熔融盐和纯液体电解质的外推表面张力：HCl、HNO(3)、H(2)SO(4)、NaCl、NaNO(3)、Na(2)SO(4)、NaHSO(4)、Na(2)CO(3)、NaHCO(3)、NaOH、NH(4)Cl、NH(4)NO(3)、(NH(4))(2)SO(4)、NH(4)HCO(3)、NH(4)OH、KCl、KNO(3)、K(2)SO(4)、K(2)CO(3)、KHCO(3)、KOH、CaCl(2)、Ca(NO(3))(2)、MgCl(2)、Mg(NO(3))(2)和 MgSO(4)。计算与实验表面张力之间的平均绝对百分比误差为 0.80%（对于 2389 个数据点）。该模型可以平滑地外推到低至 150 K 的温度。此外，该模型成功地预测了三元水混合物的表面张力；还探讨了这些计算中盐-盐相互作用的影响。
