Nonequilibrium features of the association between poly(vinylamine) and sodium dodecyl sulfate:: The validity of the colloid dispersion concept
Nonequilibrium features of the association between poly(vinylamine) and sodium dodecyl sulfate:: The validity of the colloid dispersion concept
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DOI：
10.1021/jp802196c
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发表时间：
2008-08-14
影响因子：
3.3
通讯作者：
Robert Meszaros
中科院分区：
文献类型：
--
作者：
Amalia Mezei;Pojjak, Katalin;Robert Meszaros
线性聚（乙烯胺）（PVAm）和十二烷基硫酸钠（SDS）的水性混合物的体积和表面性质的不同混合协议的影响进行了研究，使用pH值，电泳迁移率，动态光散射，凝聚动力学，和表面张力测量。对于溶液的制备，应用了两种混合方案。所谓的“停止流动混合”能够实现非常快速的混合，而在“温和混合”的情况下，组分的混合效率较低。在高表面活性剂浓度下，通过应用停流混合方法形成PVAm/SDS颗粒的动力学稳定的胶体分散体。混合方案对PVAm/SDS系统的本体性质具有显著影响，特别是在低pH范围和大PVAm浓度下。混合的效果可以定性地理解在增强的PVAm/SDS复合物的凝固的局部速率以及通过应用效率较低的混合的表面活性剂/表面活性剂聚集体的外观方面。研究还表明，溶液制备的应用方法不具有对表面活性剂的结合量以及对系统的表面张力等温线的重大影响。后一种发现归因于在空气/水界面处的大颗粒/表面活性剂聚集体的受阻吸附。
The effect of different mixing protocols on the bulk and surface properties of the aqueous mixtures of linear poly(vinylamine) (PVAm) and sodium dodecyl sulfate (SDS) has been investigated using pH, electrophoretic mobility, dynamic light scattering, coagulation kinetics, and surface tension measurements. For the preparation of the solutions, two kinds of mixing protocols were applied. The so-called "stop flow mixing" enables a very rapid mixing whereas in the case of "gentle mixing" the mixing of the components is less efficient. At high surfactant concentrations a kinetically stable colloid dispersion of the PVAm/SDS particles is formed via the application of the stop flow mixing method. The mixing protocols have a significant effect on the bulk properties of the PVAm/SDS system, in particular, at the low pH range and at large PVAm concentrations. The effect of mixing can be qualitatively understood in terms of the enhanced local rate of coagulation of the PVAm/SDS complexes as well as of the appearance of polyelectrolyte/surfactant aggregates via the application of a less efficient mixing. The study also reveals that the applied methods of solution preparation do not have a major impact on the bound amount of the surfactant as well as on the surface tension isotherms of the system. This latter finding is attributed to the hindered adsorption of the large polyelectrolyte/surfactant aggregates at the air/water interface.