NMR diffusometry of oil-in-water emulsions

The diffusion propagator of the continuons aqueous phase of concentrated oi l-in-water emulsions is used to probe the relationship between emulsion mic rostructure and bulk rheological properties. This is done by expanding the stimulated echo amplitude, S(q,Delta), as a multiple exponential time serie s expansion in Delta, with wavevector dependent expansion coefficients. The se coefficients are compared with predictions from several theoretical mode ls for three types of stable emulsion, each differing in microstructure. Em piric relationships between the wavevector expansion coefficients and bulk rheology are established. (C) 2001 Elsevier Science Inc. All rights reserve d.