- NMR as an analytical tool to characterise dispersions. CL Cooper, P Wiroonpochit, T Cosgrove, SW Prescott and D Fairhurst. UK Colloids 2011, July 2011.
High resolution NMR spectroscopy is one of the most powerful analytical tools used to probe details of molecular structure and dynamics. Such instrumentation requires very high resolution and uses extremely large, powerful magnets. However, the need for portable and unusual NMR has been evident for the past decade. With the advent of small, powerful permanent magnets a commercial instrument using low resolution NMR is already available to measure the surface area of suspensions. However, it is feasible to measure other characteristics of dispersions such as diffusion, from which size can be estimated. Further, it is possible to directly measure volume fraction and, potentially, the molecular weight of polymers. One important practical application is the ability to determine competitive adsorption and/or displacement of polyelectrolytes, macromolecules and surfactants at interfaces. The theory underpinning these new approaches to dispersion characterization will be described in detail and the factors affecting reduction to practical implementation will be discussed together with examples of each measurement. In addition, there is a synergy between NMR diffraction and both small angle light scattering (SALS) and ultra-small angle neutron scattering (USANS). This aspect will also be briefly reviewed.
Last edited: Friday September 10, 2010
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