研究界面多相吸附动力学的一个新方法——表面增强喇曼散射方法

A NEW METHOD TO STUDY THE HETEROGENEOUS ADSORPTION ON THE INTERFACES ON SURFACE ENHANCED RAMAN SCATTERING

提出利用表面增强喇曼散射(SERS)效应研究化学吸附动力学,给出了理论模型和实验方法。研究了结晶紫(CV)和对氨基苯甲酸(PABA)在银镜及银胶表面吸附。发现在银镜和银胶表面上,CV的吸附是匀相的,PABA则是多相的;表面形态的差异不影响表面多相因子和脱附速率常数(K_d=0),只对吸附速率常数有影响。讨论了表面多相因子的意义。

A new method to study chemical adsorption kinetics by means of surface enhanced raman scattering is proposed. The theoretical model is proposed and experimental results given out. The adsorption of CV and PABA molecules on the surfaces of silver mirrors and silver colloids is studied. It is found that the adsorption of CV on silver surfaces is homogeneous, and the adsorption of PABA is heterogeneous. The differences of silver surfaces only influence the adsorption rate constant Ka, not changing the heterogeneity character of adsorption and desorp-tion rate constant (Kd=0). Finally, the significance of heterogeneity paramter is discussed.