INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Chemisorbed Thiols on Silica Particles: Characterization of Reactive Sulfur Species
Autor/es:
PAULA CAREGNATO; MALCOLM D.E. FORBES; DELIA B. SORIA; DANIEL O. MÁRTIRE; MÓNICA C. GONZALEZ
Revista:
JOURNAL OF PHYSICAL CHEMISTRY C
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2010 vol. 114 p. 5080 - 5087
ISSN:
1932-7447
Resumen:
Silica particles with surface thiol groups (Sil–SH) were prepared by silylation of silanol groups using 3-mercaptopropyltrimethoxysilane. The particles were characterized by FTIR, Raman, and XPS spectroscopies, thermogravimetry, and solid state 13C and 29Si NMR spectroscopy.  Laser flash excitation at 266 nm of Sil–SH water suspensions in the presence of sodium peroxodisulfate generated sulfur-centered radicals that were attached to the silica surface.  These radicals were detected at their absorption maxima (330 nm) by transient optical techniques.  Absorbance decay signals were fit to first and second order decay kinetics, and were assigned to thiyl radicals.  Formation of disulfide radicals, a major decay channel for free thiyl radicals in solution, was not observed for surface-grafted thiyl radicals.