Open Accessβ-ray irradiation effects on silica nanoparticles
Author(s) -
A. Alessi,
S. Agnello,
Gianpiero Buscarino,
Bruno Boizot,
Marco Cannas,
F. M. Gelardi
Publication year - 2015
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/80/1/012011
Subject(s) - irradiation , electron paramagnetic resonance , nanoparticle , materials science , nuclear magnetic resonance , chemistry , radiochemistry , nanotechnology , nuclear physics , physics
By electron paramagnetic resonance (EPR) measurements, we examine the amplitude of the signal typically due to a combination of NBOHC (Non Bridging Hole Center) and POR (Peroxy Radical) defects induced by β-ray irradiation (from 1.2 to 1200 MGy) in silica nanoparticles with diameter ranging from 7 to 20 nm. Our data indicate that the signal line-shapes recorded at different doses is quite independent from the particles sizes and from the dose. Furthermore, for each considered nanoparticles size, the concentration of defects is also almost constant with respect to dose, and it does not change significantly if measured after 2 or 9 months from the irradiation. By contrast, we observed that the concentration of NBOHC+POR decreases on increasing the specific surface, indicating that the content of the defects depends on the nanoparticles size. Such dependence can be explained by a shell model in which the detected defects are located in the inner part of the nanoparticles