Trans-interface diffusion-controlled coarsening
Related Experiment Video
Updated: Aug 19, 2026

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging
Published on: September 2, 2016
Alan J Ardell1, Vidvuds Ozolins
1Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California 90095-1595, USA. aardell@ucla.edu
Abstract:
Accurate theoretical predictions of the volume-fraction dependence during diffusion-controlled coarsening of a polydisperse assembly of particles have proved difficult. Here, a new model of coarsening is presented, involving diffusive transport through the coherent interface between ordered and disordered phases, which atomistic calculations show has a ragged structure. The interface is a diffusion bottleneck when the ordered phase is dispersed. It is predicted that the square of the average radius grows linearly with time, that the depletion of solute decreases as the inverse square-root of time, and that there is no effect of volume fraction on kinetics and the scaled particle-size distributions. These differ dramatically from predictions of modern theories of diffusion-controlled coarsening. Data on coarsening in Ni-Al alloys is examined. We show that no other theory is consistent with the experimentally observed absence of an effect of volume fraction on coarsening of ordered gamma' (Ni3Al) precipitates in a disordered Ni-Al (gamma) matrix, and the strong volume-fraction dependence of coarsening of gamma precipitates in an ordered gamma' matrix.
Related Concept Videos
Theories of Dissolution: Diffusion Layer Model
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Passive Diffusion: Overview and Kinetics
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...
Diffusion
Diffusion
Facilitated Diffusion
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...

