Trujillo-Cayado Luis Alfonso, Ramírez Pablo, Alfaro María Carmen, Ruíz Manuela, Muñoz José
Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, c/P, García González, 1, E41012 Sevilla, Spain.
Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, c/P, García González, 1, E41012 Sevilla, Spain.
Colloids Surf B Biointerfaces. 2014 Oct 1;122:623-629. doi: 10.1016/j.colsurfb.2014.07.041. Epub 2014 Aug 4.
In this contribution, we provide an accurate characterization at the α-pinene/water interface of two commercial polyoxytheylene glycerol ester surfactants which differ in the number of ethylene oxide (EO) groups, comprising a systematic analysis of interfacial pressure isotherms, dynamic curves, interfacial rheology and emulsifying properties. Polyoxyethylene glycerol esters derived from cocoa oil are non-ionic surfactants obtained from a renewable source which fulfill the environmental and toxicological requirements to be used as eco-friendly emulsifying agents. α-Pinene is a renewable biosolvent completely insoluble in water, which could find numerous applications. Interfacial rheology and equilibrium interfacial pressure data fitted a rigorous reorientation model that assumes that the surfactant molecules, when adsorbed at the interface, can acquire two orientations. The surfactant with the highest number of EO groups (Levenol C201) turned out to be more surface active at the α-pinene/water interface. In addition, the surfactant with the lowest number of EO groups (Levenol H&B) is solubilized into the adjacent oil phase. Slightly concentrated α-pinene emulsions were obtained using both surfactants. Nevertheless, more stable α-pinene emulsions with smaller droplet sizes and lower polidispersity were obtained when Levenol C201 was used as emulsifier instead of Levenol H&B. The systematic characterization presented in this work provides important new findings on the interfacial and emulsifying properties of polyoxytheylene glycerol ester surfactants, which can be applied in the rational development of new biocompatible products.
在本论文中，我们对两种商业聚氧乙烯甘油酯表面活性剂在α-蒎烯/水界面进行了精确表征，这两种表面活性剂的环氧乙烷（EO）基团数量不同，包括对界面压力等温线、动态曲线、界面流变学和乳化性能的系统分析。源自可可油的聚氧乙烯甘油酯是非离子表面活性剂，来自可再生资源，满足作为环保乳化剂使用的环境和毒理学要求。α-蒎烯是一种完全不溶于水的可再生生物溶剂，具有众多应用。界面流变学和平衡界面压力数据符合一个严格的重定向模型，该模型假设表面活性剂分子在界面吸附时可获得两种取向。EO基团数量最多的表面活性剂（Levenol C201）在α-蒎烯/水界面表现出更高的表面活性。此外，EO基团数量最少的表面活性剂（Levenol H&B）可溶解于相邻的油相。使用这两种表面活性剂均获得了轻度浓缩的α-蒎烯乳液。然而，当使用Levenol C201而非Levenol H&B作为乳化剂时，可获得具有更小液滴尺寸和更低多分散性的更稳定的α-蒎烯乳液。本工作中呈现的系统表征为聚氧乙烯甘油酯表面活性剂的界面和乳化性能提供了重要的新发现，可应用于新型生物相容性产品的合理开发。
