title: Surface hydration and its effect on fluorinated SAM formation on SiO2 surfaces.
abstract: Substrate hydration is demonstrated to be crucial to film quality during self-assembled (SA) film deposition of tridecafluoro-1,1,2,2,-tetrahydrooctyltrichlorosilane (FOTS) from the vapor phase. The surface hydration was studied by thermogravimetric analysis, and a model was developed to predict the conditions necessary to desorb all of the water adsorbed on a fused silica surface without significantly altering the concentration of the surface hydroxyl groups. The nature of the SA film was investigated as a function of the degree of rehydration of the dehydrated silica surface. The wettability and microstructure of the SA films were examined by water contact angle, ellipsometry, X-ray photoelectron spectroscopy, and atomic force microscopy. There is an optimum degree of substrate hydration, on the order of 1-1.2 monolayers of adsorbed water, required to produce a dense, durable and uniform FOTS film with high water repellency and a smooth surface.
authors.affiliation: Department of Chemical Engineering, University of Texas at Austin, 78712, USA.
authors.forename: K
authors.initials: K
authors.lastname: Wu
authors.forename: T C
authors.initials: TC
authors.lastname: Bailey
authors.forename: C G
authors.initials: CG
authors.lastname: Willson
authors.forename: J G
authors.initials: JG
authors.lastname: Ekerdt