Document Type
Article
Publication Date
8-16-2019
Publication Source
Physical Chemistry Chemical Physics
Abstract
Applications of self-assembled monolayers (SAMs) on surfaces are prevalent in modern technologies and drives the need for a better understanding of the surface domain architecture of SAMs. To explore structural interaction at the interface between gold surfaces and a hydroxyl-terminated alkanethiol, 11-hydroxy-1-undecanethiol, (C11TH) we have employed a combined computational and experimental approach. Density functional theory (DFT) calculations were carried out on the thiol–gold interface using both the Perdew–Burke–Ernzerhof (PBE) and van der Waals (optB86b) density functionals. Our ab initio molecular dynamics (AIMD) simulations revealed that the interface consists of four different distinguished phases, each with different C11TH orientations. Experiments involved deposition of C11TH SAMs onto gold, with the resultant surfaces examined with X-ray photoelectron spectroscopy (XPS) and ellipsometry. Weighted average projected density of states (PDOS) of the different phases were photoionization cross section corrected and these were confirmed by experimental XPS data. Computed molecular parameters including tilt angles and the thickness of SAMs also agreed with the XPS and ellipsometry results. Hydrogen bonding arising from the terminal hydroxyl groups is the primary factor governing the stability of the four phases. Experimental results from XPS and ellipsometry along with DFT simulation results provide insights into the formation of the different orientations of SAM on Au(111) which will guide future efforts in the self-assembled SAMs architecture for other thiols or metal substrates.
ISBN/ISSN
1463-9076 (print); 1463-9084 (web)
Document Version
Postprint
Publisher
Royal Society of Chemistry
Volume
21
Peer Reviewed
yes
Issue
42
eCommons Citation
Roy, Juganta K.; Vasquez, Erick S.; Pinto, Henry P.; Kumari, Swati; Walters, Keisha B.; and Leszcynski, Jerzy, "Computational and Experimental Approach to Understanding the Structural Interplay of Self-Assembled End-Terminated Alkanethiolates on Gold Surfaces" (2019). Chemical and Materials Engineering Faculty Publications. 227.
https://ecommons.udayton.edu/cme_fac_pub/227
COinS
Comments
The document available for download is the authors' accepted manuscript, provided in compliance with the publisher's policy on self-archiving. Permission documentation is on file. To view the version of record, use the DOI: https://doi.org/10.1039/C9CP03613J