title: Liquid mechanical behavior of mixed monolayers of amino and alkyl silanes by atomic force microscopy.
abstract: The adsorption of mixed terminally aminated organosilyl compounds with long-chain n-alkyltrichlorosilanes on silica substrates has been studied by FTIR and AFM to deposit and study DNA. By optimization of deposition conditions, the mixed monolayers were found to be well organized and homogeneous. The amino group was protected to obtain a reproducible grafting and then deprotected after the film formation. In addition, atomic force microscopy (AFM) studies in both dynamical modes, amplitude modulation and frequency modulation, reveal that the layer behaves as a fluid as measured by the tip-cantilever and has a smaller characteristic time than the tip-cantilever. For three amplitudes, the experimental frequency shifts have been modeled for a fluidlike layer crossed by the tip. Finally, we show that this new fluidlike monolayer is suitable for DNA deposition and AFM studies.
authors: Centre de Physique Moléculaire Optique et Hertzienne, UMR 5798 CNRS, Université Bordeaux 1, 351 cours de la Libération, 33405 Talence Cedex, France.
authors: Pascal
authors: P
authors: Martin
authors: Sophie
authors: S
authors: Marsaudon
authors: Laurent
authors: L
authors: Thomas
authors: Bernard
authors: B
authors: Desbat
authors: Jean-Pierre
authors: JP
authors: Aimé
authors: Bernard
authors: B
authors: Bennetau
mesh_terms: D018625:Microscopy, Atomic Force / Q000379:methods*; D012821:Silanes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D012821:Silanes