标题： 热响应性刷状聚电解质与相反电荷表面活性剂的络合：温度和表面活性剂浓度的影响 显示英文标题

标题： Complexation of a Thermoresponsive Brush-Type Polyelectrolyte with an Oppositely Charged Surfactant: Effect of Temperature and Surfactant Concentration

摘要： 响应性药物输送载体可以使用带相反电荷的聚电解质-表面活性剂复合物来设计。 作为模型，我们创建了一种刷状共聚物（PECop），结合了海藻酸盐和聚（N-异丙基丙烯酰胺）（PNIPAAm），其侧链对温度有响应。 研究了PECop与阳离子表面活性剂十二烷基三甲基溴化铵（DTAB）在不同表面活性剂浓度和温度下的聚集情况。 我们使用表面张力、电泳迁移率、Zeta电位、电位滴定、光散射和原子力显微镜来分析这些复合物。 在特定的表面活性剂范围内，PECop/DTAB复合物形成球形、单分散的聚集体，尽管该共聚物本身是多分散的。 结合等温线结合了带相反电荷的聚电解质/表面活性剂系统和疏水改性聚合物的特征。 与单独的海藻酸盐相比，PECop在1 mM表面活性剂浓度下能结合六倍的DTAB。 温度响应性取决于表面活性剂浓度（cs）。 表面活性剂引发聚合物链的逐步塌陷，在cs = 2.8 mM时达到最大值，此时热响应性消失。 对于cs 10 mM，尺寸在LCST以上增加。 随着表面活性剂浓度升高，热响应性的反转表明聚集结构发生变化，为利用这些聚合物-表面活性剂复合物设计药物输送系统提供了新的途径。 显示英文摘要

摘要： Responsive drug delivery vectors can be designed using oppositely charged polyelectrolyte-surfactant complexes. As a model, we created a brush-type copolymer (PECop), combining alginate and Poly(N-isopropylacrylamide) (PNIPAAm), whose side chains respond to temperature. Aggregation of PECop with the cationic surfactant dodecyltrimethylammonium bromide (DTAB) was examined versus surfactant concentration and temperature. We used surface tension, electrophoretic mobility, zeta potential, potentiometry, light scattering, and atomic force microscopy to analyze the complexes. PECop/DTAB complexes form spherical, monodisperse aggregates in certain surfactant ranges, even though the copolymer itself is polydisperse. The binding isotherms combine features of oppositely charged polyelectrolyte/surfactant systems and hydrophobically modified polymers. Compared to alginate alone, PECop binds six times more DTAB at 1 mM surfactant concentration. Temperature responsiveness depends on surfactant concentration (cs). The surfactant triggers progressive collapse of polymer chains, maximized at cs = 2.8 mM, where thermo-responsiveness is lost. For cs 10 mM, size increases above LCST. This inversion in thermal response with rising surfactant concentration suggests changing aggregate structure, offering new avenues for drug delivery system design using these polymer-surfactant complexes.