Porometrie

Porometrie, or porometry, is a set of analytical techniques used to characterize the pore structure of porous materials. It aims to quantify pore size distributions, pore volume, porosity, and related properties that influence transport, accessibility, and performance in applications such as filtration, catalysis, and soil science. Different methods probe different pore size ranges and pore features, making porometry a complementary toolkit rather than a single measurement.

Common porometry techniques include mercury intrusion porosimetry (MIP), gas adsorption porosimetry, capillary flow porometry, and imaging-based approaches. Mercury intrusion porosimetry measures the volume of mercury forced into pores under increasing pressure to derive pore throat diameters, typically covering a wide range from nanometers to tens of micrometers but requiring careful handling due to mercury toxicity and potential pore collapse during measurement. Gas adsorption porosimetry uses adsorption isotherms of gases such as nitrogen or argon to determine surface area (BET method) and pore size distribution (BJH, DFT). Capillary flow porometry assesses the largest pore openings by monitoring the point at which a wetting liquid can be displaced by gas flow, useful for membranes and filters with pore sizes from sub-micron to tens of microns. Imaging methods, including X-ray computed tomography, can provide 3D pore structure information for larger, heterogeneous samples.

Outputs from porometry typically include pore size distribution, cumulative porosity, total pore volume, and surface area or pore connectivity. The interpretation of results depends on the method and model used, and measurements can be sensitive to sample preparation and assumptions about pore geometry. Porometry is widely used in material science, geology, environmental engineering, membrane technology, and related fields to inform material design and quality control.