Mikroporiset

Mikroporiset (microporous materials) are solids containing a substantial fraction of pores smaller than 2 nanometers. The presence of sub-nanometer to nanometer pores leads to high internal surface areas and strong size- and shape-selective adsorption. Microporosity is defined in contrast with mesoporosity (2–50 nm) and macroporosity (greater than 50 nm).

Common examples include zeolites, activated carbons, and certain metal-organic frameworks and covalent organic frameworks that feature predominantly microporous structures. Zeolites are crystalline aluminosilicates with rigid pore networks shaping catalytic and separation properties. Activated carbons are typically amorphous carbon with a broad micropore distribution; many MOFs and COFs can be designed to be microporous.

Synthesis often involves hydrothermal or solvothermal methods, templating approaches, or activation steps. Characterization relies on gas adsorption measurements, especially nitrogen sorption at 77 K, to determine surface area (BET) and pore-volume distribution. Micropore analysis may use NLDFT or t-plot methods to quantify micropore volume.

Applications span gas storage and separation (such as CO2 capture and H2 storage), catalysis (zeolites and MOF-based catalysts), environmental remediation, and sensing. Stability and performance depend on composition: zeolites are typically thermally and chemically robust, while some MOFs offer high porosity but can be moisture-sensitive; carbons vary in chemical resistance.