1. Theoretical elements

1.1 Definitions

• Porosity

  It's the volume of a substance's void relative to its total volume. Porosity is expressed as a percentage. The porosity of a solid layer is determined by the shape and arrangement of its particles. Maximum porosity is achieved when the particles are all of the same size, or when the particle size spectrum of the components is narrow. Porosity should not be confused with pore diameter, as is often the case. The notion of pore diameter corresponds to the definition of the filtration threshold