FUNCTIONALIZATION OF HYDROXYL AND CARBOXYLIC-ACID TERMINATED SELF-ASSEMBLED MONOLAYERS

The functionalization of monolayers of mercaptopropanol (MPL) and merc aptopropanoic acid (MPA) adsorbed onto surfaces of gold has been studi ed using X-ray photoelectron spectroscopy and contact angle goniometry . The terminal hydroxyl goups of the MPL monolayers were derivatized w ith the vapor from either trifluoroacetic anhydride, pentafluoropropan oic anhydride, or heptafluorobutyric anhydride to yield highly hydroph obic, CF3 functionalized surfaces. For the MPA monolayers the carboxyl ic acid groups at the surface were derivatized by reaction with the va por from trifluoroethanol, pyridine, and di-tert-butylcarbodiimide. Th is resulted in only similar to 60% of the surface carboxyl groups unde rgoing reaction in contrast to the 100% derivatization of poly(acrylic acid), indicating a difference in reactivity of these two materials.