Hilles Hani M, Ritacco Hernán, Monroy Francisco, Ortega Francisco, Rubio Ramón G
Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain.
Langmuir. 2009 Oct 6;25(19):11528-32. doi: 10.1021/la9014515.
The equilibrium isotherms of monolayers of poly(4-hydroxystyrene) on the air/water interface have been studied in the 5-60 degrees C range. The results indicate that the interface is a poor solvent for the monolayers over the whole temperature range. For surface pressures within the semidilute regime, the plot of the area occupied by the polymer coils versus temperature at constant surface pressure shows a sharp change of slope near 30 degrees C. Also, the surface excess entropy shows a similar change of slope at the same temperature. The surface shear viscosity can be described by a power law of the surface concentration. Within the semidilute regime, the exponent of the power law changes. The temperature dependence of the viscosity points out a change from independent particle to collective dynamics.
已研究了聚（4-羟基苯乙烯）单层在空气/水界面上5-60摄氏度范围内的平衡等温线。结果表明，在整个温度范围内，该界面对于单层来说是不良溶剂。对于半稀溶液区域内的表面压力，在恒定表面压力下聚合物线团占据的面积与温度的关系图在30摄氏度附近显示出斜率的急剧变化。此外，表面过量熵在相同温度下也显示出类似的斜率变化。表面剪切粘度可用表面浓度的幂律来描述。在半稀溶液区域内，幂律的指数发生变化。粘度的温度依赖性表明从独立粒子动力学转变为集体动力学。
