ABSTRACT
Introduction .......................................................................................................... 79
Length Scales of Gels and Emulsions............................................................... 81
Emulsions ...................................................................................................... 82
Gels................................................................................................................. 83
Mass Transport Studies Using a Combination of Microscopy and
NMR Diffusometry.......................................................................................... 85
Diffusion in Heterogeneous Materials...................................................... 86
General Features of Emulsions and Gels................................................. 89
Microstructure-Based Modeling of Water Diffusion .............................. 91
Microstructure ...................................................................................... 91
Calculation of the Propagator............................................................ 92
Comparisons between Microstructure-Based Diffusion
Calculations and NMR Diffusometry .......................................... 93
Probe Diffusion............................................................................................. 95
Acknowledgments ............................................................................................... 97
References ............................................................................................................. 98
Many products are composed of heterogeneous structures of vital
importance to properties such as the diffusion of water and soluble
compounds, release of active compounds, behavior of molecules in complex
structures, consistency, microbial growth, water binding, etc. Yet there is a
lack of knowledge about how to use microstructure design to tailor-make
properties related to water management. One reason is that we know too
little about how a certain complex structure affects the mass transport in
relation to heterogeneity or connectivity over a wide range of length scales.
We also lack techniques for approaching time-dependent structural changes
and interactions between the material and the solvents or solutes.