A theoretical model for the transport of solute through hydrogels containing oil droplets
Related Experiment Video
Updated: Oct 30, 2026

Microfluidic Devices for Characterizing Pore-scale Event Processes in Porous Media for Oil Recovery Applications
Published on: January 16, 2018
Joseph J Webber1, Stefan A F Bon2, Thomas D Montenegro-Johnson1
1Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK. joe.webber@warwick.ac.uk.
Abstract:
Hydrogels are often used as reservoirs for chemicals such as drugs or soil treatments, but they can release their payload much too quickly as they dry out or as solute simply diffuses through the water in the gel. It is known that doping gels with oil droplets, creating a material known as an 'emulgel', can trap solute and slow this release, but quantifying this effect is challenging. In this paper, we introduce a new approach to deduce the effective transport properties of an inhomogeneous porous medium comprising two distinct solvent phases which interact with a solute species in different ways. We then show that a rigorous mathematical approach built on the separation of timescales between bulk transport and solute trapping can give an expression for the effective diffusivity as a function of the amount of oil present and its distribution, outlining the application of these composite materials to systems delivering beneficial agents for pharmaceutical and agricultural purposes.
More Related Videos
12:07Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning
Published on: April 16, 2018
08:02Fabricating High-viscosity Droplets using Microfluidic Capillary Device with Phase-inversion Co-flow Structure
Published on: April 17, 2018
Related Concept Videos
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
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...
Fluid Mosaic Model
The Colloidal State
Osmosis
Water, like other substances, moves from a high concentration of free water...
Capillarity in Fluid
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...