Langmuir, Vol.16, No.7, 3294-3303, 2000
Self-assembled monolayers of alkanoic acids: A solid-state NMR study
Long-chain alkanoic acids (CH3(CH3)(n)CO2H, n > 15) form conformationally ordered monolayers on zirconium oxide powder via a chelating bidentate zirconium carboxylate surface bond. omega-Hydroxyalkanoic acids (HO(CH3)(15)CO2H) produce hydrophilic monolayers, with no evidence of looping to the metal oxide surface. Variable temperature and two-dimensional solid-state NMR experiments demonstrate that alkanoate monolayers display chain dynamics similar to other self-assembled monolayers (SAMs). The thermal behavior of alkanoate SAMs is also compared to analogous fatty acid salt Langmuir-Blodgett, monolayers which undergo pretransitional chain disordering.
Keywords:ORDER-DISORDER TRANSITIONS;LANGMUIR-BLODGETT-FILMS;REFLECTION-ABSORPTION SPECTROSCOPY;ORGANIZED MOLECULARASSEMBLIES;OXIDIZED ALUMINUM SURFACE;FT-IR;INFRARED-SPECTROSCOPY;CADMIUM ARACHIDATE;FATTY-ACID;STRUCTURALCHARACTERIZATION