Self-assembly of organothiols on metals (Cu, CuNi, Ni and Au)

Résumé

The research work described in this thesis focuses on surface functionalization of Nickel (Ni) substrate using thiol molecules. In addition to Ni metal, self-assembly of different molecules on Copper-Nickel (CuNi) Copper (Cu) and Gold (Au) are also studied. Cu, CuNi and Ni have interesting applications in alloys, batteries, electroplating, catalyst, corrosion resistance etc.
The main aim of this thesis is to form stable thiol self-assembled monolayers (SAMs) on Ni using simple techniques. To achieve objective, chemical reduction using reducing agent and electrochemical reduction in ionic liquid are carried out.
The thiol monolayers formed are analyzed using various characterization techniques such as water contact angle, surface roughness measurements, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), polarization curve and electrochemical impedance spectroscopy (EIS).
Finally, both chemical and electrochemical reduction methods described in this work forms good thiol monolayers of n-dodecanethiol (C12SH) on Ni substrates. The Cu forms stable SAMs with 11-mercaptoundecanoic acid (11-MUA) while CuNi and Ni form poor monolayers.
In the annexes, self-assembling mechanisms of various thiols, dithiols, dithiocarboxylic acids, disulphides and diselenides are studied using in situ electrochemical impedances (EIS) technique on gold (Au) metal used as model system. The kinetics of adsorption mechanism occurring from few milliseconds to several hours was extensively studied.

la date de réponse	9 sept. 2016
langue originale	Anglais
L'institution diplômante	Universite de Namur
Sponsors	CERUNA
Superviseur	Zineb Mekhalif (Promoteur), Anne Lemaitre (Président), Joseph DELHALLE (Jury), Catherine Michaux (Jury), Arnaud Delcorte (Jury) & Patricia Losada-Perez (Jury)