porozimetry

Porozimetry is a scientific technique used to determine the pore size distribution and pore volume of a material. This is achieved by measuring the volume of a fluid that enters or leaves the pores of a sample as a function of applied pressure. The most common method employed in porozimetry is mercury intrusion porosimetry (MIP), which utilizes mercury, a non-wetting liquid, to probe the porous structure. Due to mercury's low surface tension and high contact angle with most solids, it will only enter pores when sufficient pressure is applied.

The pressure required for mercury to penetrate a pore is inversely proportional to the pore's diameter. This relationship is described by the Washburn equation, which forms the basis for calculating pore sizes from the applied pressure. As pressure increases, mercury intrudes into progressively smaller pores. By monitoring the volume of mercury intruded at each pressure increment, a cumulative intrusion curve is generated. This curve, when differentiated, provides the pore size distribution, indicating the relative abundance of pores within specific size ranges.

Porozimetry finds wide applications in various fields. In materials science, it is crucial for characterizing porous ceramics, catalysts, filters, and construction materials, influencing properties like permeability, strength, and surface area. In geology, it helps analyze reservoir rocks, soil porosity, and the properties of porous media. In pharmaceuticals, it is used to study drug delivery systems and tablet porosity. The technique can reveal important information about connectivity, tortuosity, and the overall pore network structure of a material, contributing significantly to material design and understanding.