用状态方程模拟氨基酸水溶液的热力学性质

Modeling Thermodynamic Properties for Amino Acid Aqueous Solutions Using Equation of State

将变阱宽方阱链流体状态方程(SWCF-VR)应用到氨基酸水溶液系统热力学性质计算中,结合氨基酸水溶液的密度得到了17种氨基酸分子的模型参数。纯粹根据氨基酸和水分子的模型参数,SWCF-VR方程能预测17种氨基酸水溶液在不同温度和组成下的密度,总的平均相对偏差为0.43%,结果令人满意。如引入与温度相关的可调参数,该方程能高精度关联氨基酸水溶液的密度,总的平均相对偏差仅为0.012%。通过所获得的可调参数,SWCF-VR方程能预测所选氨基酸在水中的溶解度。

An equation of state for square-well chain fluids with variable range （SWCF-VR） was applied to calculate thermodynamic properties of amino acid aqueous solutions. The model parameters for 17 amino acids were obtained by combining the densities of amino acid aqueous solutions. SWCF-VR can give satisfactory prediction by only using molecular parameters of amino acid and water, and the overall average relative deviation （ARD） of density was 0.43%. Using an adjustable parameter associated with temperature, the density of binary solutions of amino acids can be correlated with a high precision, and ARD was only 0. 012%. Coupling with an adjustable parameter from density data, SWCF-VR can successfully predict the solubility of amino acid selected in water.