Dynamics of the liquid surface by surface-area control light scattering technique

到目前为止，我们建立的ripplon光散射技术是能够在宽频带内观察发生在液体表面的表面张力波（ripplon）的传播和色散的技术。本研究所改良之装置，是在控制样品表面面积与状态的同时，加装新概念的光槽，并同时进行光散射量测。用这种方法研究了液体表面及其附近的分子动力学，并将这些结果与由表面压力-浓度曲线估计的表面吸附密度进行了关联，并利用朗缪尔吸附方程进行了关联。提出了两种可能的机制：一种是吸附在表面上的分子之间的重新取向或重新分配;另一种是假设表面上的分子和亚表面中的分子具有高能量势垒的两态模型。

The ripplon light scattering technique that we caused established up to now is the technology that is able to observe the propagation and dispersion of the surface tension wave (ripplon) that happen to a/the liquid surface in a wide band. The device that we improved with this research installs the trough of a new concept and do light scattering measurement simultaneously while controlling the area and condition of a/the specimen surface. By using this method we did the study of the molecule dynamics of a/the liquid surface and the surface vicinity.These results were correlated with the surface adsorption density estimated by the observed curves of surface pressure vs. concentration with the aid of Langmuir's equation of adsorption. Two possible mechanisms of the very slow process were proposed : one is the re-orientation or re-distribution among the molecules adsorbed on the surface ; and the other assumes a two-state model with a high energy barrier for the molecules on the surface and those in the subsurface.