Poregeometrie

Poregeometrie, known in English as pore geometry, refers to the size, shape, and spatial arrangement of pores within a porous material. It is a fundamental aspect of pore structure alongside porosity and pore size distribution, and it strongly influences transport, diffusion, adsorption, and reaction processes inside the material. Characteristic features include pore size distribution, pore shape (for example cylindrical, slit, or ink-bottle geometries), pore throat size, porosity (volume fraction occupied by pores), connectivity between pores, tortuosity of flow paths, and surface roughness.

Characterization methods include gas adsorption (BET, BJH) for micro- and mesopores, mercury intrusion porosimetry for larger pores, small-angle scattering (SAXS/SANS) for nanometer scales, and X-ray micro-computed tomography for three-dimensional imaging. Image analysis of microscopy data and computational tools enable quantification of pore-size distributions, throat sizes, connectivity, and tortuosity, sometimes described with parameters such as transport tortuosity or Euler characteristic. Fractal or multi-scale models are used to relate geometry to transport properties.

Understanding and controlling pore geometry is important in catalysts, adsorbents, membranes, energy storage materials, and soils. The geometry determines effective diffusivity, permeability, and selectivity, as well as accessible surface area and reaction rates. In material design, synthetic strategies such as templating, phase separation, etching, or 3D printing aim to create targeted pore geometries to optimize performance.

Because real materials are heterogeneous and anisotropic, pore geometry often varies with scale, requiring multi-scale and multimodal characterization. Advances in imaging and modeling continue to improve the reliability of geometry-based predictions.