WETTABILITY OF FLUORO- AND CHLOROCARBON TRIALKOXYSILANE FILMS ADSORBED ON GLASS AND METAL SURFACES

Adsorbed films having a wide range of wettabilities were formed on silica, Pyrex, aluminosilicate, α-alumina, steel and gold by trialkoxysilane (and trichlorosilane) compounds. These compounds had the general formulas, RSi(OR)3 or RSiCl3, where R-was a fluorocarbon or a chlorocarbon group and -OR was -OCH3 or -OCH2CH3. The fluorocarbon films had γe values of <20 dynes/cm and water contact angles of 100-115 degrees. The chlorocarbon films had γe values of >40 dynes/cm and water contact angles of 80-90 degrees. Film thickness, determined by ellipsometry, was consistently greater than a monolayer of the trialkoxysilane. Desorption experiments suggest that the films were composed of a polysiloxane network along with unhydrolyzed adsorbate, small polysiloxane molecules and solvent. © 1968.