Pordiameter

Pordiameter is the characteristic size of pores within a porous material, typically expressed as a diameter. The term is commonly used in discussions of pore-size distributions (PSD), where a material contains pores across a range of sizes, and pordiameter can refer to a representative value such as a mean, modal, or median diameter depending on the method and context.

Measurement and interpretation: Pordiameter is determined using several techniques. Mercury intrusion porosimetry probes pore sizes from the nanometer to tens of micrometers, while gas adsorption methods (such as BET with BJH or NLDFT analyses) are used to characterize mesopores and micropores. Direct imaging with scanning electron microscopy (SEM) or transmission electron microscopy (TEM) can provide local pore size estimates. In some cases, distinctions are made between pore diameter and pore throat diameter, the latter describing constrictions that control fluid passage. Data are typically presented as a pore-size distribution, with summary statistics including mean, modal, and volume-based diameters.

Applications and significance: Pordiameter is a key parameter in membranes, catalysts, adsorbents, energy storage materials, and soils. It influences fluid flow resistance, diffusive transport, surface area accessibility, and the overall performance of a material. Materials are often engineered to achieve a target pordiameter to balance permeability, selectivity, capacity, and mechanical stability.

See also: pore size distribution, porosity, pore throat, mercury intrusion porosimetry, gas adsorption, SEM/TEM imaging.