M. Lelli et al., Fast Characterization of Functionalized Silica Materials by Silcion-29 Surface-Enhanced NMR Spectroscopy Using Dynamic Nuclear Polarization, J. Am. Chem. Soc., 2010,
http://pubs.acs.org/doi/abs/10.1021/ja110791d
We demonstrate fast characterization of the distribution of surface bonding modes and interactions in a series of functionalized materials via surface-enhanced nuclear magnetic resonance spectroscopy using dynamic nuclear polarization (DNP). Surface-enhanced silicon-29 DNP NMR spectra were obtained by using incipient wetness impregnation of the sample with a solution containing a polarizing radical (TOTAPOL). We identify and compare the bonding topology of functional groups in materials obtained via a sol-gel process and in materials prepared by post-grafting reactions. Furthermore, the remarkable gain in time provided by surface-enhanced silicon-29 DNP NMR spectroscopy (typically on the order of a factor 400) allows the facile acquisition of two-dimensional correlation spectra.