Self-assembled porous media from particle-stabilized emulsions

TL;DR

This paper introduces a novel method for creating self-assembled porous media with customizable pore sizes and permeability by solidifying particle-stabilized emulsions, useful for filters and reactors.

Contribution

It presents a new mechanism to produce tunable porous structures from particle-stabilized emulsions, with control over pore size and permeability through particle wettability and concentration.

Findings

Permeability can vary by up to three orders of magnitude.

Modifying particle wettability or concentration alters pore structure.

Bijels are identified as optimal structures for applications.

Abstract

We propose a new mechanism to create self-assembled porous media with highly tunable geometrical properties and permeabilities: We first allow a particle-stabilized emulsion to form from a mixture of two fluids and colloidal particles. Then, either one fluid phase or the particle layer is solidified, which can be achieved by techniques such as polymerization or freezing. Based on computer simulations we demonstrate that modifying only the particle wettability or concentration results in porous structures with a wide range of pore sizes and a permeability that can be varied by up to three orders of magnitude. We then discuss optimization of these properties for self-assembled filters or reactors and conclude that structures based on so-called "bijels" are most suitable candidates.