Abstract The equilibrium solubility of 5-chloro-8-hydroxyquinoline [cloxiquine] (Form Ⅰ) from 278.15 to 323.15 K in three binary solvent systems [(2-ethoxyethanol, n-propyl acetate and 1,4-dioxane) + ethanol] was measured by using laser monitoring method. The obtained results indicated that the solubility of cloxiquine was found to increase monotonically with the augmented of system temperatures and mass fraction of (2-ethoxyethanol, 1,4-dioxane or n-propyl acetate) in binary solvent mixtures. Moreover, experimental cloxiquine solubility was adequately correlated with the three-suffix Margules model, NRTL model, Wilson model and UNQUAC model, with the best fitting from the UNIQUAC model. Furthermore, the thermodynamic parameters (entropy, Gibbs energy and enthalpy changes) of mixing and dissolution processes were computed from the accurate solubility data using the UNIQUAC model. In this context, the relevant analysis about positive entropy change and negative Gibbs energy change indicated that the whole dissolution process was confirmed to entropy-driving and spontaneous.

中文翻译：

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5-氯-8-羟基喹啉在 T = 278.15 至 323.15 K 的二元溶剂混合物中的溶解度测定和热力学模型

摘要 5-氯-8-羟基喹啉[氯氧喹]（I型）在三种二元溶剂体系[（2-乙氧基乙醇、乙酸正丙酯和1,4-二恶烷）+乙醇]中的平衡溶解度为278.15至323.15 K采用激光监测法测量。所得结果表明，随着体系温度和（2-乙氧基乙醇、1,4-二氧六环或乙酸正丙酯）在二元溶剂混合物中的质量分数的增加，发现氯氧喹的溶解度单调增加。此外，实验中的氯氧喹溶解度与三后缀 Margules 模型、NRTL 模型、Wilson 模型和 UNQUAC 模型有充分的相关性，与 UNQUAC 模型的最佳拟合。此外，热力学参数（熵、使用 UNIQUAC 模型从准确的溶解度数据计算混合和溶解过程的吉布斯能和焓变。在此背景下，正熵变和负吉布斯能量变化的相关分析表明，整个溶解过程被证实为熵驱动和自发。