Surfactant-Like Behavior for the Adsorption of Mixtures of a Polycation and Two Different Zwitterionic Surfactants at the Water/Vapor Interface
Surfactant-Like Behavior for the Adsorption of Mixtures of a Polycation and Two Different Zwitterionic Surfactants at the Water/Vapor Interface
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DOI：
10.3390/molecules24193442
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发表时间：
2019-10-01
期刊：
影响因子：
4.6
通讯作者：
Rubio, Ramon G.
中科院分区：
文献类型：
--
作者：
Akanno, Andrew;Guzman, Eduardo;Rubio, Ramon G.
由聚阳离子（即，聚（二烯丙基二甲基氯化铵），PDADMAC）和两种不同的两性离子表面活性剂（即，椰油基甜菜碱（CB）和椰油酰胺丙基甜菜碱（CAPB））。通过浊度和电泳迁移率测量分析了聚乙二醇和两种表面活性剂的本体聚集，并通过表面张力和界面扩张流变学测量研究了溶液在流体界面处的吸附。只有当表面活性剂分子的数量接近溶液中带电单体的数量时，才发现大量聚合物-表面活性剂复合物形成的证据，这表明与表面活性剂中带正电基团的存在相关的静电排斥阻碍了PDADMAC和两性离子表面活性剂之间的关联，其中溶液中没有胶束。这种在本体中缺乏相互作用反映在混合物的界面性质中不存在表面活性剂的影响，其行为由表面活性剂的存在控制。这项工作证明了系统中所涉及的不同相互作用对于控制聚电解质-表面活性剂混合物中的相互作用和络合机制的重要性。
The bulk and interfacial properties of solutions formed by a polycation (i.e., poly(diallyl-dimethylammonium chloride), PDADMAC) and two different zwitterionic surfactants (i.e., coco-betaine (CB) and cocoamidopropyl-betaine (CAPB)) have been studied. The bulk aggregation of the polyelectrolyte and the two surfactants was analyzed by turbidity and electrophoretic mobility measurements, and the adsorption of the solutions at the fluid interface was studied by surface tension and interfacial dilational rheology measurements. Evidence of polymer-surfactant complex formation in bulk was only found when the number of surfactant molecules was closer to the number of charged monomers in solutions, which suggests that the electrostatic repulsion associated with the presence of a positively charged group in the surfactant hinders the association between PDADMAC and the zwitterionic surfactant for concentrations in which there are no micelles in solution. This lack of interaction in bulk is reflected in the absence of an influence of the polyelectrolyte in the interfacial properties of the mixtures, with the behavior being controlled by the presence of surfactant. This work has evidenced the significant importance of the different interactions involved in the system for controlling the interaction and complexation mechanisms of in polyelectrolyte-surfactant mixtures.