gamma radiolyzed amorphous silica:A study with ~(29)Si CP-MAS NMR spectroscopy

摘要

Precipitated amorphous silica has been y radiolyzed at 333,666 and 1000 kGy in air.The structural changes undergone during irradiation have been studied by ~(29)Si CP-MAS NMR spectroscopy.The spectra suggest that silica looses the hydrogen atoms attached to the silanol groups and the resulting silanol radicals undergo a crosslinking reaction by forming peroxysiloxane groups or by reacting with E'centres yielding siloxane groups.