Application of solid state carbon‐13 NMR spectroscopy to chemically modified surfaces

Abstract The nuclear magnetic resonance (NMR) techniques, high‐power decoupling, magic‐angle spinning, and cross polarization for high resolution in solid materials have been utilized to characterize surface‐modified silicas. Solid state Carbon‐13 NMR was used to study the chemical adsorption of a series of organosilane coupling agents on the silica surface. The type of information that can be obtained from such surface studies includes chemical bonding between the surface and the organosilane, the effects on steric hindrance of the hydrocarbon chains of the coupling agent, and other silane‐surface interactions. The approach for the analysis involved comparing the spectra of the treated silica to the spectra of the corresponding condensed coupling agents. Spectral differences in terms of changes in chemical shifts and line widths are observed. The results are interpreted in terms of chemical bonding and structural differences of the silane coupling agents adsorbed onto the surface.