Dominique Costa1,2, Bice Fubini1,2, Elio Giamello1,2, Marco Volante1,2
1Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, via Pietro Giuria 9, 10125 Torino, Italy
2Pnnled In Canada i ImpnmC au Canada
Tóm tắt
A new type of surface site, different from those previously described, which gives rise to a paramagnetic oxygen species upon adsorption of O2 at low temperature, has been found at the surface of crystalline quartz. This site is abundant on freshly cleaved surfaces or on chemically etched ones but absent on crystal growth faces or on samples annealed at high temperature. The abundance of this site is not related to the other surface radicals characteristic of the quartz surface originated by mechanical grinding in air. The EPR spectral features of the signal suggest an ozonide type radical O3−. The adsorption of oxygen onto quartz dusts variously treated in order to modulate their fibrogenic potential in vivo indicates that a relationship may exist between the presence of this site and quartz pathogenicity. Key words: quartz, oxygen radical species, ozonide, silicosis, EPR.
