DIFFUSION THROUGH SINGLE POROUS PARTICLES STUDIED IN A MICROFLUIDIC SYSTEM

Abstract

The understanding of diffusion through porous materials is a crucial aspect for designing superior catalysts. Their performance is often influenced by inter-particle inhomogeneities, which are barely attainable with bulk analytical methods. To overcome this problem, a microfluidic system has been designed and fabricated to perform a mass transfer study at a single-particle level using fluorescence microscopy. This was done by trapping a porous particle and applying a concentration gradient over it. The system allows us to obtain the true value of the diffusion coefficient of a single particle, which is not averaged over many particles and influenced by inter-particle porosity. The diffusion was studied for a Fluid Catalytic Cracking (FCC) and a porous SiO2 particle, the latter well-known material used as a commercial support material.