PhD Candidate
DIMHTRIOS STEFANAKIS
dimstef@materials.uoc.gr
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Title
Modeling the interactions between thiols and complex gold surfaces
Supervisor
REMEDIAKIS IOANNIS, Associate Professor, Materials Science & Technology Dept. - UOC
Committee Members
KOPIDAKIS GEORGIOS, Associate Professor, Materials Science & Technology Dept. - UOC
HARMANDARIS EVAGGELOS, Associate Professor, Dept. of Mathematics and Applied Mathematics - UOC
Abstract
The Self-Assembled Monolayers (SAMs) consist of relatively short alkane molecules (10-20 methylene groups) where their terminal methyl (R or –CH3) group has been replaced by a functional group (e.g. ‑SH) and have been adsorpted onto various metal surfaces (e.g. Au, Ag, etc.). Although there have been a lot of studies concerning the interaction between alkanethiols and the planar Au(111) surface, this is not true for other complex Au surfaces like Au(211), Au(321) etc that can be found on various nanostructures (like Au NPs). The important fact is that these surfaces contain anomalies that increase their activity. Our endeavor is to study the characteristics and properties of Au-S interaction in SAMS at complex surfaces by the developement of a new effective empirical potential that can describe the bond. In order to develop this potential, we use data coming either from the literature or by performing new calculations to produce them, in case that they are not exist elsewhere, using Quantum Mechanics simulations with Density Functional Theory. On the other hand, we intend to use this empirical potential to investigate some interesting structural features of various sized SAMs by performing Molecular Dynamics simulations, starting with small structures containing one S atom and various numbers of C atoms on several Au complex surfaces and extending them to bigger ones with hundreds of S atoms. The properties of SAMs make them very useful for a lot of applications. Experiments for studying specific structural features of monomolecular films and the affection in the structure of them that is caused by the chemical alterations in the chain backbone or the terminal group use alkanethiol-based SAMs as prototypical models. More than that, the above calculations might lead further to new experiments concerning the synthesis of new materials based on NPs for a number of applications such as ultra-hard coatings, high selectivity catalysts, smart materials for drug delivery, fine-tuned optoelectronic devices, various biomedical applications, non-fouling surfaces, SAMs with specific binding receptors, molecular electronics etc.