Abstract A new technique of utilizing the dynamic surface tension (ST) data for solubility determination was proposed, tested, and verified in this study. Dibutyl phthalate was chosen as the surface-active component and its solutions were prepared with 0, 1, and 5 wt.% aqueous methanol (MeOH) solutions. The solutions for ST measurement were prepared by stirring the aqueous DBP mixtures in a heated water bath (45 °C) for an extended duration of time. The data revealed that an increase in DBP concentration corresponded to a more rapid relaxation of dynamic ST and reached a lower equilibrium ST; similar to that observed amongst typical micelle forming surfactants (at C cmc, the dynamic ST relaxations became increasingly rapid. These inconsistencies in dynamic ST behavior pointed towards the absence of micelle formation amongst the DBP molecules. Based on the dynamic ST data, the solubility of DBP in water, 1 wt.%, and 5 wt.% MeOH(aq) were found to be ∼6.1, ∼4.4, and ∼4.7 (10−8 mol/cm3), respectively.

中文翻译：

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从动态表面张力数据确定表面活性成分的溶解度

摘要 本研究提出、测试并验证了一种利用动态表面张力（ST）数据进行溶解度测定的新技术。选择邻苯二甲酸二丁酯作为表面活性成分，并用 0、1 和 5 重量% 的甲醇 (MeOH) 水溶液制备其溶液。通过在热水浴 (45 °C) 中长时间搅拌 DBP 水溶液混合物，制备用于 ST 测量的溶液。数据显示，DBP 浓度的增加对应于动态 ST 的更快速松弛并达到较低的平衡 ST；类似于在典型的胶束形成表面活性剂中观察到的（在 C cmc，动态 ST 弛豫变得越来越快。动态 ST 行为中的这些不一致表明 DBP 分子之间没有胶束形成。