CHARACTERIZATION OF TIO2 PIGMENTS BY AL-27 NMR

Titanium oxide pigments, coated with SiO2-AlO3 system, prepared follow ing four different synthesis ways, have been characterised by Al-27 hi gh resolution solid-state NMR. The spectra of these ''model'' pigments depend upon the synthesis path and the annealing temperature. MQ-MAS experiments are used to separate the different contributions, which ov erlap in the usual single pulse experiment MAS spectrum. From CPMAS an d REDOR experiments, it is possible to describe further the different Al-6 species evidenced by MQ-MAS.