title: Adsorption of silanes bearing nitrogenated Lewis bases on SiO2/Si (100) model surfaces.
abstract: The present paper describes the one-pot procedure for the formation of self-assembled thin films of two silanes on the model oxidized silicon wafer, SiO2/Si. SiO2/Si is a model system for other surfaces, such as glass, quartz, aerosol, and silica gel. MALDI-TOF MS with and without a matrix, XPS, and AFM have confirmed the formation of self-assembled thin films of both 3-imidazolylpropyltrimethoxysilane (3-IPTS) and 4-(N-propyltriethoxysilane-imino)pyridine (4-PTSIP) on the SiO2/Si surface after 30 min. Longer adsorption times lead to the deposition of nonreacted 3-IPTS precursors and the formation of agglomerates on the 3-IPTS monolayer. The formation of 4-PTSIP self-assembled layers on SiO2/Si is also demonstrated. The present results for the flat SiO2/Si surface can lead to a better understanding of the formation of a stationary phase for affinity chromatography as well as transition-metal-supported catalysts on silica and their relationship with surface roughness and ordering. The 3-IPTS and 4-PTSIP modified SiO2/Si wafers can also be envisaged as possible built-on-silicon thin-layer chromatography (TLC) extraction devices for metal determination or N-heterocycle analytes, such as histidine and histamine, with "on-spot" MALDI-TOF MS detection.
authors.affiliation: Universidade de São Paulo, Instituto de Química de São Carlos, P.O. Box 780, 13564-970 São Carlos, Brazil.
authors.forename: Juliana Salvador
authors.initials: JS
authors.lastname: Andresa
authors.forename: Rafael Machado
authors.initials: RM
authors.lastname: Reis
authors.forename: Eduardo Perez
authors.initials: EP
authors.lastname: Gonzalez
authors.forename: Leonardo Silva
authors.initials: LS
authors.lastname: Santos
authors.forename: Marcos Nogueira
authors.initials: MN
authors.lastname: Eberlin
authors.forename: Pedro Augusto
authors.initials: PA
authors.lastname: de Paula Nascente
authors.forename: Sonia Tomie
authors.initials: ST
authors.lastname: Tanimoto
authors.forename: Sérgio Antônio Spínola
authors.initials: SA
authors.lastname: Machado
authors.forename: Ubirajara P
authors.initials: UP
authors.lastname: Rodrigues-Filho