Porometric

Porometric is an adjective used to describe methods, devices, and data associated with porometry, the measurement of pore structure in porous materials. Porometric techniques aim to characterize pore size distribution, pore throat size, total porosity, and pore connectivity, which influence how fluids or gases move through a material.

The most common porometric approaches include capillary flow porometry and gas permeation porometry. Capillary flow porometry typically involves saturating a sample with a wetting liquid and then applying gas from the opposite side to displace the liquid. The pressure at which a continuous gas breakthrough occurs (the bubble point) is related to the largest pore throat, and gradual pressure increases yield a distribution of pore sizes. Gas permeation porometry measures permeability as a function of pressure to infer pore size characteristics, often focusing on transport through the pore network. Mercury intrusion porosimetry is a related technique that uses controlled mercury intrusion to derive pore size distributions, though it is a separate category of porosimetry due to the use of a liquid metal and high pressures.

Applications of porometric analysis span membranes and filtration media, catalysts and catalyst supports, battery separators, ceramics, soils, rocks, and wood. In each case, porometric data help assess filtration efficiency, permeability, mechanical stability, and fluid transport properties.

Interpretation of porometric data requires awareness of limitations: measured pore sizes reflect accessible, connected pores under specific test conditions and wetting media, and closed or blocked pores may be underrepresented. Sample preparation and surface chemistry can influence results, so porometric measurements are typically complemented by other porosity and pore-structure analyses to provide a complete picture.