Solid-state nuclear magnetic resonance studies of heterogeneous materials

Solid-state NMR has been applied to the study of two types of heterogeneous materials: bone and polymer-clay nanocomposites. Each has useful and unexpected properties that are largely determined by the interfacial region between the two components making up each material rationalization of these properties at a molecular level is essential if we are to intelligently design new materials, which might mimic bone for instance. In Chapter 3. 2D experiments that correlate the T1 relaxation time by the chemical shift are described and their application to the study of the interfacial region in Fe3+ substituted polymer-clay nanocomposites is described. It is found that in polyhydroxyethylmethacrylate nanocomposites the polymer is significantly more ordered at the surface than in polymethylmethacrylate nanocomposites. In Chapter 5, a variety of techniques that explicit the dipolar coupling between 31P in the inorganic phase and 13C in the organic matrix of equine bone are used, with the aim of identifying the proteins and/or the amino acid residues responsible for the binding of the two phases and the nature of the interaction between the phases. Natural equine bone samples (i.e. non-isotopically enriched) are studied to give the first experimental evidence that (i) it is predominantly glutamate residues that are bound to the inorganic surface with a d-13C-31P distance in the range 0.45-0.5 nm. (ii) no P-O-C bonds occur and (iii) that proline and hydroxyproline are not involved in binding. Finally, in Chapter 6, solid-state NMR is applied to the study of osteoarthritic equine bone samples with a view to characterizing the changes in bone composition and structure that occur with this disease.EThOS - Electronic Theses Online ServiceGBUnited Kingdo