Development of low-frequency domain spectroscopy at liquid interfaces using ultra-short laser pulse and its applications

这项研究的目的是在低频域观察分子在液体界面上的集体行为。首先，作为研究分子在液界面上集体行为的重要系统，我们研究了表面活性剂分子在非线性化学振荡系统中的动力学行为和生物膜的水解反应动力学。我们在中获得了关于这些系统的新信息。根据离子在膜上传递的动力学行为和界面上离子与分子之间的特殊相互作用，我们研制了在低频域观测液体界面分子集合体振动光谱的装置。通过倍频信号的变化，我们成功地获得了GaAs板表面的低频振动谱。由于分子组装体或晶格的相干振动引起的非线性极化率的变化。我们还将暂态光栅结构应用到上述系统中，成功地从香豆素染料分散的气/液界面获得了无背景信号。

The aim of this research is the observation of the collective behavior of the molecular a ssemblies at liquid interfaces in the low-frequency domain. At first, as important systems of the collective behaviors of the molecular assemblies at liquid interfaces, we investigate d the dynamic behavior of surfactants molecules in nonlinear chemical oscillation system and the kinetics of the hydrolysis reactions of biological membrane. We obtained new information of these systems in. terms of the dynamic behavior of the ion transfer across the membrane and specific interaction between ions and molecules at the interfaces.We have developed the equipment to observe vibrational spectra of the molecular assemblies at liquid interfaces in low-frequency domain. We have succeeded to obtain low-frequency vibrational spectrum from the surface of GaAs plate through the change of SHG signals. induced by the change of the nonlinear susceptibility due to the coherent vibration of the molecular assemblies or lattices. We have also applied the transient grating configuration to the abovementioned system, we successfully obtained background free signal from the air/liquid interface where coumarin dyes were dispersed.