Fourier transform infrared spectrometry (FTIR) showed the increase of band at 2855 cm-1 and 2965 cm-1 , assigned to symmetric and asymmetric of CH2, respectively, of SAM of AUT, indicating the more perpendicular orientation of AUT molecules compared with MUA molecules on the Au(111) surface. This result interpreted the degree of phase separation in binary SAMs of AUT-MeOH compared with binary SAMs of MUA-MeOH. | Vietnam Journal of Chemistry, International Edition, 55(2): 178-182, 2017 DOI: Miscibility in two phase-separated binary self-assembled monolayers composed of hydrophilic components on Au(111) Pham Hong Phong Institute of Chemistry, Vietnam Academy of Science and Technology Received 16 September 2016; Accepted for publication 11 April 2017 Abstract The typical characteristic of two binary self-assembled monolayer (SAMs) composed of 11-aminoundecanethiol hydrochloride (AUT), and 10-carboxy-1-decanethiol (MUA) in each and the other was 2-hydroxylethanethiol (MeOH) was investigated. The dependence of charges (Q), estimated from the peak areas in cyclic voltammograms on the mixing ratios of components ( solMeOH) indicated that QMUA = QMeOH at solMeOH = , meanwhile QAUT = QMeOH at sol MeOH = , suggesting that adsorbed MUA molecules prevented the adsorption of MeOH molecules. Fourier transform infrared spectrometry (FTIR) showed the increase of band at 2855 cm-1 and 2965 cm-1, assigned to symmetric and asymmetric of CH2, respectively, of SAM of AUT, indicating the more perpendicular orientation of AUT molecules compared with MUA molecules on the Au(111) surface. This result interpreted the degree of phase separation in binary SAMs of AUT-MeOH compared with binary SAMs of MUA-MeOH. Keywords. Binary self-assembled monolayers, miscibility, hydrophilic components. 1. INTRODUCTION Self-assembled monolayers (SAMs) are nanostructured materials that have been attractive to many studies because they provide a convenient, flexible and simple system to tailor the interfacial properties of metals, metal oxides, and semiconductors [1]. The most extensively studied class of SAMs is derived from the adsorption of alkanethiols on substrates such as gold, silver, copper, and mercury. The high affinity of thiols for the surfaces of noble and coinage metals makes it possible to generate well-defined organic surfaces with useful and highly alterable .
