micropores (rus. микропоры) — pores with diameter less than 2 nm.


Dimension-based classification of pores into micropores, mesopores and macropores was suggested by the International Union of Pure and Applied Chemistry (IUPAC). Micropores are occasionally classified into smaller-size ultramicropores (less than 0.7 nm) and supermicropores that are larger than ultramicropores but smaller than mesopores. The surface of microporous systems is vast and may reach many thousand square metres per gram of material. Microporous materials include carbon absorbents, silica gels, zeolites, certain clay types, etc. Due to the small distance between the pore walls, the absorption mechanism in micropores is drastically different from absorption of a flat surface or in large pores. For this reason, a special volume filling theory was developed to describe this mechanism.

Special research methods should be used to examine the texture and morphology of micropores. The most common method is the energy method implemented in two different ways - by calculating the characteristic energy based on absorption data or by defining the heat of wetting; other methods used include small-angle X-ray scattering, high-definition electronic microscopy, molecular probing and other methods.


  • Smirnov Andrey V.
  • Tolkachev Nikolay N.


  1. Everett D.H. Manual of Symbols and Terminology for Physicochemical Quantities and Units: Appendix II: Definitions, terminology and symbols in colloid and surface chemistry. Part 1: Colloid and surface chemistry // Pure Appl. Chem. 1972. V. 31. P. 577–638.
  2. Rouquerol J., Avnir D. et al. Recommendations for the characterization of porous solids // Pure and Appl. Chem. 1994. V. 66. P. 1739–1758.
  3. Karnaukhov A.P. Adsorption. The texture of dispersed and porous materials. - Novosibirsk: Nauka, 1999. - 470. p. (in Russian).

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