Au(111)上烷烃硫醇SAMs表面应力的理论研究  

Theoretical Study on Adsorbate-Induced Surface Stress in the Self-Assembly of Alkanethiols on Gold

作　　者：谢蓉[1] 陈东明[1] 何天敬[1] 刘凡镇[1] 

机构地区：[1]中国科学技术大学化学物理系,合肥230026

出　　处：《Chinese Journal of Chemical Physics》2004年第5期525-530,共6页化学物理学报（英文）

基　　金：ProjectsupportedbytheNationalNaturalScienceFoundationofChina(20173051);theNaturalScienceFoundationofAnhuiprovince(01046302)andThePh.D.ProgramsFoundationofMinistryofEducationofChina.

摘　　要：应用已建立的关于金属表面吸附层中表面应力的统计热力学理论 ,计算了Au(111)上烷烃硫醇SAMs的表面应力及其与烷烃硫醇链长、吸附覆盖度的定量关系 .计算结果与实验相符 ,较好地解释了Berger等人的实验结果 ,特别是解决了在表面应力符号性质上理论与实验的矛盾 .在表面吸附层应力的多种物理起源中 ,通过底物的分子间作用力有着决定性的贡献 ,揭示了分子的吸附能间接地起着重要作用 .这与阴离子化学吸附体系Cl-/Au(111)的有关研究结果相同 .By using the established statistical thermodynamic theory of adsorbate-induced surface stress of adsorption monolayer on the metal surface, the surface stress △g in the self-assembly of alkanethiols on Au(111) surface has been calculated. The quantitative relations of the surface stress △g with the length N of the alkyl chain of the molecule and with the coverage θ of molecules on Au(111) have been theoretically studied respectively. The calculated results agree with Berger et al′s experiment, and especially the quantitative discrepancy between the theory and experiment on the sign of the surface stress has been resolved. Among various components of the adsorbate- adsorbate interaction energies in the adlayer, the substrate mediated interaction is significant for the adsorbate-induced surface stress, which shows that the indirect contribution of the adsorption energy of alkanethiols through the substrate-mediated interaction is very important. This physical mechanism is similar to that for chloride monolayer on the Au(111) electrode.

关 键 词：自组织单分子层(SANs) 表面应力 分子间作用力 格子气模型 

分 类 号：O647.11[理学—物理化学]