Swelling of a polymer brush probed with a quartz crystal resonator
Swelling of a polymer brush probed with a quartz crystal resonator
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DOI：
10.1103/physreve.56.680
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发表时间：
1997-07-01
影响因子：
2.4
通讯作者：
Johannsmann, D
中科院分区：
文献类型：
--
作者：
Domack, A;Prucker, O;Johannsmann, D
我们用石英谐振器和椭偏仪研究了聚苯乙烯刷在环己烷中溶胀的温度依赖性。随着温度的升高，已经共价结合到二氧化硅表面的层的膨胀不断增加。来自石英谐振器的数据显示为“薄膜共振”，这表明刷子的厚度约为横声波波长的数量级。定量分析表明，石英谐振器测得的声学厚度高于椭偏仪测得的光学厚度。我们认为，这种差异的部分原因是声学测量中获得的高对比度，这使得石英谐振器对节段密度分布尾部的稀释区最敏感。讨论了声学厚度与流体力学厚度之间的关系。
We have studied the temperature dependence of swelling of a polystyrene brush in cyclohexane with quartz resonators and ellipsometry. The swelling of the layer, which has been covalently bound to a silicon oxide surface, continuously increases as the temperature is raised. The data from the quartz resonator display a ''film resonance,'' which indicates that the thickness of the brush is on the order of the wavelength of transverse sound. The quantitative analysis shows that the acoustic thickness as determined with the quartz resonator is higher than the optical thickness from ellipsometry. We argue that this difference is partly due to the high contrast achieved in acoustical measurements, which makes the quartz resonator most sensitive to dilute regions in the tail of the segment density profile. The relation between the acoustic thickness and the hydrodynamic thickness is discussed.