Why does pore size matter in chemical filtration?

In filtration, pore size is the fundamental factor that determines which particles are retained and which are allowed to pass through the medium. Because filtration relies on the physical size of particles to achieve separation, the dimensions of the pores dictate the precision of the process.1

When pore sizes are highly uniform, the filtration process becomes more sensitive, allowing for a more refined separation based on specific particle diameters. Conversely, when pore sizes are varied or large, the method is typically utilized for gross separations, such as isolating liquids from suspended solids or crystals. By selecting a medium with an appropriate pore size, chemists can effectively control the distribution of particles and ensure the desired purity of the resulting substances.1