Effect of Solution Composition on the Desorption Behavior of Self-Assembled Monolayers of Alkanethiols with Different Terminal Groups

• Published in: Russian journal of electrochemistry Vol. 60; no. 4; pp. 283 - 289
• Main Authors: Ovchinnikova, S. N., Aleksandrova, T. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.04.2024; Springer Nature B.V
• Subjects: Alkanes; Cations; Chemistry; Chemistry and Materials Science; Composition; Desorption; Electrochemistry; Monolayers; Physical Chemistry; Protonation; Self-assembled monolayers; Self-assembly; Stability; Thiols; gold; self-assembly; adsorption; cyclic voltammetry; alkanethiols; desorption peak
• ISSN: 1023-1935; 1608-3342
• DOI: 10.1134/S1023193524040062

Voltammetry and chronoamperometry are used to study the effect of the solution composition on the desorption behavior of self-assembled monolayers of alkanethiols with approximately the same chain length but different terminal groups of thiols (R: –CH 3 , –CH 2 OH, and –NH 2 ). The hydrophilic properties of the terminal groups for the studied thiols increased in the –CH 3 –NH 2 ≤ –CH 2 OH series. It is found that the anionic and cationic composition of electrolyte affected significantly the electrochemical stability and blocking ability of self-assembled monolayers of thiols with different terminal groups. It is established that the electrochemical stability and blocking ability of the self-assembled monolayers decreased in the Li + , Na + , K + series in alkaline solutions regardless of the thiol terminal group. The cation nature in perchlorate and chloride solutions manifested itself only for thiol with the –NH 2 terminal group. The shape of cathodic voltammograms changed for this thiol when passing from alkaline to and Сl – medium, possibly owing to a change in the amino group protonation degree.