NMR INVESTIGATIONS OF THE SILANOPHILIC INTERACTIONS OF ALKYL-MODIFIEDSILICA

The C-13 NMR spin lattice relaxation times have been measured for susp ensions of chemically bonded silica particles in solutions of an organ ic base in deuteroacetonitrile, CD3CN, at different base concentration s. A correlation has been observed between the relaxation rates and th e ratio of the amounts of base and silica in the suspension. Thus, sil anophilic interactions of chemically bonded silicas can be monitored u sing C-13 NMR relaxation rates. The correlation is interpreted in term s of the rapid exchange model. The method seems to have potential for the rapid and accurate determination of equilibrium isotherms.