Phase separation of binary self-assembled thiol monolayers composed of 1-hexadecanethiol and 3-mercaptopropionic acid on Au(111) studied by scanning tunneling microscopy and cyclic voltammetry
Phase separation of binary self-assembled thiol monolayers composed of 1-hexadecanethiol and 3-mercaptopropionic acid on Au(111) studied by scanning tunneling microscopy and cyclic voltammetry
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DOI：
10.1016/s0022-0728(97)00553-6
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发表时间：
1998-03-05
影响因子：
4.5
通讯作者：
Kakiuchi, T
中科院分区：
文献类型：
--
作者：
Hobara, D;Ota, M;Kakiuchi, T
用循环伏安法和扫描隧道显微镜研究了十六烷基硫醇（HDT）和巯基丙酸（MPA）在Au（111）表面自组装膜的混合特性。在吸附的硫醇分子的还原解吸的循环伏安图上，在整个表面组成范围内观察到两个不同的峰，相隔0.45V，这反映了两种不同类型的相分离域的存在，其大于几十nm（2），可以通过扫描隧道显微镜成像。1-十六烷基硫醇的峰电位几乎与表面组成无关，而MPA的峰电位略有偏移，表明HDT微溶于MPA结构域，而MPA不溶于HDT结构域。显示两个不同峰（即二维整体性质）所需的吸附硫醇分子的最小数量估计为约1000。50通过比较循环伏安图与通过扫描隧道显微镜观察到的畴尺寸的分布。(C)1998年Elsevier Science S.A. All rights reserved.
The mixing characteristics of binary self-assembled monolayers composed of 1-hexadecanethiol (HDT) and 3-mercaptopropionic acid (MPA) on Au(111) have been studied by cyclic voltammetry and scanning tunneling microscopy. Two distinctive peaks, similar to 0.45V apart, are observed over the entire range of surface composition on cyclic voltammograms for the reductive desorption of the adsorbed thiol molecules, which reflects the presence of two different types of phase-separated domains greater than several tens of nm(2) which can be imaged by scanning tunneling microscopy. The peak potential of 1-hexadecanethiol is nearly independent of the surface composition whereas a slight shift of the peak potential is observed in the case of MPA, suggesting that the HDT is slightly soluble in the MPA domains, while MPA is insoluble in the HDT domains. The minimum number of the adsorbed thiol molecules required for exhibiting two distinctive peaks (i.e. two-dimensional bulk properties) is estimated to be ca. 50 by comparing the cyclic voltammograms with the distribution of the domain size observed by scanning tunneling microscopy. (C) 1998 Elsevier Science S.A. All rights reserved.