Fernández-Peña Laura, Guzmán Eduardo, Fernández-Pérez Coral, Barba-Nieto Irene, Ortega Francisco, Leonforte Fabien, Rubio Ramón G, Luengo Gustavo S
Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
Centro de Espectroscopía y Correlación, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
Polymers (Basel). 2022 Mar 25;14(7):1335. doi: 10.3390/polym14071335.
Mixtures of polyelectrolytes and surfactants are commonly used in many technological applications where the challenge is to provide well-defined modifications of the surface properties, as is the case of washing formulations in cosmetics. However, if contemporary experimental and theoretical methods can provide insights on their behavior in concentrated formulations, less is known on their behavior under practical use conditions, e.g., under dilution and vectorization of deposits. This makes it difficult to make predictions for specific performance, as, for example, good hair manageability after a shampoo or a comfortable sensorial appreciation after a skin cleanser. This is especially important when considering the formulation of new, more eco-friendly formulations. In this work, a detailed study of the phase separation process induced by dilution is described, as well as the impact on the deposition of conditioning material on negatively charged surfaces. In order to gain a more detailed physical insight, several polyelectrolyte-surfactant pairs, formed by two different polymers and five surfactants that, although non-natural or eco-friendly, can be considered as models of classical formulations, have been studied. The results evidenced that upon dilution the behavior, and hence its deposition onto the surface, cannot be predicted in terms of the behavior of simpler pseudo-binary (mixtures of a polymer and a surfactant) or pseudo-ternary mixtures (two polymers and a surfactant). In many cases, phase separation was observed for concentrations similar to those corresponding to the components in some technological formulations, whereas the latter appeared as monophasic systems. Therefore, it may be assumed that the behavior in multicomponent formulations is the result of a complex interplay of synergistic interactions between the different components that will require revisiting when new, more eco-sustainable ingredients are considered.
聚电解质和表面活性剂的混合物常用于许多技术应用中，这些应用面临的挑战是对表面性质进行明确的改性，化妆品中的洗涤配方就是如此。然而，尽管当代实验和理论方法能够深入了解它们在浓缩配方中的行为，但对于它们在实际使用条件下（例如在沉积物稀释和载体化过程中）的行为却知之甚少。这使得难以对特定性能进行预测，例如洗发水后良好的头发梳理性能或皮肤清洁剂后的舒适感官体验。在考虑新型、更环保配方的配制时，这一点尤为重要。在这项工作中，描述了对稀释诱导的相分离过程的详细研究，以及对调理材料在带负电表面上沉积的影响。为了获得更详细的物理见解，研究了由两种不同聚合物和五种表面活性剂形成的几对聚电解质 - 表面活性剂，尽管这些聚合物和表面活性剂并非天然或环保型，但可被视为经典配方的模型。结果表明，稀释后其行为以及在表面上的沉积情况，无法根据更简单的假二元混合物（聚合物和表面活性剂的混合物）或假三元混合物（两种聚合物和一种表面活性剂）的行为来预测。在许多情况下，在与某些技术配方中成分浓度相似时观察到相分离，而后者表现为单相系统。因此，可以假设多组分配方中的行为是不同组分之间协同相互作用复杂 interplay 的结果，当考虑新型、更具生态可持续性的成分时，这需要重新审视。
