US EPA

3859500 

Journal Article 

Thermal stability of thiol and silane monolayers: A comparative study 

Chandekar, A; Sengupta, SK; Whitten, JE 

2010 

Yes 

Applied Surface Science
ISSN: 0169-4332 

256 

9 

2742-2749 

10.1016/j.apsusc.2009.11.020 

WOS:000274153800014 

The stability of self-assembled monolayers (SAMs) at elevated temperatures is of considerable technological importance. The thermal stability of 1-octadecanethiol (ODT), 16-mercaptohexadecanoic acid (MHDA) and 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT) SAMs on gold surfaces, and of 4-aminobutyltriethoxysilane (ABTES) and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDS) assembled on hydroxylated silicon surfaces, was studied by X-ray photoelectron spectroscopy (XPS). The samples were heated in ultrahigh vacuum to temperatures in excess of that required for SAM degradation. ODT monolayers were stable to ca. 110 degrees C, while MHDA and PFDT SAMs were stable to ca. 145 degrees C. ABTES SAMs were found to be indefinitely stable to 250 degrees C, while PFDS SAMs were stable to 350 degrees C. These studies demonstrate the advantages of using silane monolayers for moderate to high temperature applications and illustrate differences that arise due to the nature of the tail group. To demonstrate the feasibility of silanes for template-directed patterning, a hydroxylated silicon oxide surface containing microcontact-printed PFDS patterns was spin-coated with a mainly hydrophilic block copolymer. Annealing the surface at 90 degrees C for 2 h caused the block copolymer to dewet the hydrophobic PFDS-patterned regions and adsorb exclusively on the unpatterned regions of the surface. (C) 2009 Elsevier B. V. All rights reserved. 

Thermal stability; Monolayer; Thiol; Silane; XPS; Microcontact printing