Multi-scale NMR characterisation of mesostructured materials using 1H-->13C through-bond polarisation transfer, fast MAS, and 1H spin diffusion.
A NMR method for the characterisation of materials at different length scales, robust and simple to implement, is presented. It combines selection of 1H-13C pairs by a through-bond polarisation transfer (INEPT here) and exploration of larger distances by the introduction of 1H spin diffusion. This characterisation method is well adapted to the highest MAS rates and takes benefits of it. The effect of 1H dephasing on the efficiency of the 1H-->13C through-bond polarisation transfer is determined. This allows consecutively the quantification of signals. Mesostructured spherical silica-based particles containing CTA+ cations were studied by this multi-scale characterisation method. Contrasted spin diffusion curves were found and qualitatively explained by differences in terms of mobility and spatial distributions.
Alonso
Bruno
B
CRMHT-CNRS, 1D avenue de la Recherche Scientifique, 45071 Orléans 2, France. alonso@cnrs-orleans.fr
Massiot
Dominique
D
D002247:Carbon Isotopes; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D003102:Colloids / Q000737:chemistry*; D003461:Crystallography / Q000379:methods*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D016062:Porosity; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry; D013113:Spin Labels
D002247:Carbon Isotopes; D002593:Cetrimonium Compounds; D003102:Colloids; D011522:Protons; D013113:Spin Labels; D012825:Silicon; D000077286:Cetrimonium