CEQUINOR   05415
CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
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. MA´RTIRE; MÓNICA C. GONZALEZ
Revista:
J. Phys. Chem. C
Editorial:
Elsevier
Referencias:
Año: 2010 vol. 114 p. 5080 - 5080
ISSN:
1932-7455
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. 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. 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. 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. -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. 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. 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.