mesoporous

Mesoporous refers to porous materials containing pores with diameters between 2 and 50 nanometers, a size range defined by IUPAC. The mesoporous class includes both ordered materials with periodic pore arrays and non-ordered materials with interconnected mesopores. Common examples are mesoporous silica types such as MCM-41 and SBA-15, as well as mesoporous carbons and metal oxides.

Most mesoporous materials are prepared by templating: soft templating uses surfactant molecules that organize into micelles around which silica or other framework materials condense; hard templating uses solid templates to imprint a pore network that is later removed. Template removal typically occurs by calcination or solvent extraction, yielding accessible pore channels. Pore size, connectivity, and wall thickness can be tuned by changing template size, synthesis conditions, and post-synthesis treatments.

Mesoporous materials exhibit high surface areas (often several hundred m2/g), tunable pore volumes, and pore architectures that influence mass transport and diffusion. Surface chemistry can be modified by functionalization to create acidic or basic sites or to graft organic groups, expanding chemical compatibility.

Applications span catalysis, adsorption and separations, drug delivery, energy storage, and sensing. In catalysis, mesoporous supports host active phases with accessible active sites; in drug delivery, pore size controls release; in energy storage, mesoporous carbons and silicas support ions and electrolytes.

Characterization typically uses nitrogen adsorption-desorption isotherms (BET surface area, BJH pore size distribution), transmission electron microscopy or scanning electron microscopy for structure, and small-angle X-ray scattering for pore ordering. Pore connectivity and stability under operating conditions are important design considerations.