“…The spectrum of dried K-PPA showed the four hydroxyl stretching bands of the raw kaolinite (3693, 3668, 3653 and 3619 cm À1 ) in very small intensities (Olejnik et al, 1968;Frost, 1995;Frost et al, 1997;Balan et al, 2001;Bougeard et al 2000); bands characterizing the P-C 6 H 5 bond and the phenyl ring (1436, 1487, 1594 cm À1 , four bands in the 3000À3100 cm À1 region); and very intense PÀO stretching bands between 1000 and 1300 cm À1 (Thomas & Chittenden, 1970;Cabeza et al, 1998;Haky et al, 1997;Morizzi et al, 2000;Breitinger et al, 2001). The SiÀO stretching bands (1114, 1102, 1030 and 1009 cm À1 ) and the SiÀOÀAl/OÀSiÀO bending bands (538, 470 and 431 cm À1 ) (Olejnik et al, 1968;Frost, 1995;Frost et al, 1997;Balan et al, 2001;Bougeard et al, 2000) were largely reduced in intensity or absent.…”