Kelarakis Antonios, Chaibundit Chiraphon, Krysmann Marta J, Havredaki Vasiliki, Viras Kyriakos, Hamley Ian W
National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece.
J Colloid Interface Sci. 2009 Feb 1;330(1):67-72. doi: 10.1016/j.jcis.2008.10.045. Epub 2008 Oct 22.
The interactions of sodium dodecyl sulfate (SDS) with poly(ethylene oxide)/poly(alkylene oxide) (E/A) block copolymers are explored in this study. With respect to the specific compositional characteristics of the copolymer, introduction of SDS can induce fundamentally different effects to the self-assembly behavior of E/A copolymer solutions. In the case of the E(18)B(10)-SDS system (E = poly(ethylene oxide) and B = poly(butylene oxide)) development of large surfactant-polymer aggregates was observed. In the case of B(20)E(610)-SDS, B(12)E(227)B(12)-SDS, E(40)B(10)E(40)-SDS, E(19)P(43)E(19)-SDS (P = poly(propylene oxide)), the formation of smaller particles compared to pure polymeric micelles points to micellar suppression induced by the ionic surfactant. This effect can be ascribed to a physical binding between the hydrophobic block of unassociated macromolecules and the non-polar tail of the surfactant. Analysis of critical micelle concentrations (cmc(*)) of polymer-surfactant aqueous solutions within the framework of regular solution theory for binary surfactants revealed negative deviations from ideal behavior for E(40)B(10)E(40)-SDS and E(19)P(43)E(19)-SDS, but positive deviations for E(18)B(10)-SDS. Ultrasonic studies performed for the E(19)P(43)E(19)-SDS system enabled the identification of three distinct regions, corresponding to three main steps of the complexation; SDS absorption to the hydrophobic backbone of polymer, development of polymer-surfactant complexes and gradual breakdown of the mixed aggregates.
本研究探讨了十二烷基硫酸钠（SDS）与聚环氧乙烷/聚环氧烷烃（E/A）嵌段共聚物的相互作用。鉴于共聚物的特定组成特征，SDS的引入可对E/A共聚物溶液的自组装行为产生根本不同的影响。在E(18)B(10)-SDS体系中（E = 聚环氧乙烷，B = 聚丁烯氧化物），观察到形成了大型表面活性剂 - 聚合物聚集体。在B(20)E(610)-SDS、B(12)E(227)B(12)-SDS、E(40)B(10)E(40)-SDS、E(19)P(43)E(19)-SDS体系中（P = 聚环氧丙烷），与纯聚合物胶束相比形成了更小的颗粒，这表明离子表面活性剂诱导了胶束抑制。这种效应可归因于未缔合大分子的疏水嵌段与表面活性剂的非极性尾部之间的物理结合。在二元表面活性剂的正规溶液理论框架内对聚合物 - 表面活性剂水溶液的临界胶束浓度（cmc(*)）进行分析，结果显示E(40)B(10)E(40)-SDS和E(19)P(43)E(19)-SDS出现负偏差，而E(18)B(10)-SDS出现正偏差。对E(19)P(43)E(19)-SDS体系进行的超声研究能够识别出三个不同区域，对应于络合的三个主要步骤；SDS吸附到聚合物的疏水主链上、聚合物 - 表面活性剂复合物的形成以及混合聚集体的逐渐分解。
