MCM-41 - A MODEL SYSTEM FOR ADSORPTION STUDIES ON MESOPOROUS MATERIALS

Purely siliceous MCM-41 materials with different pore sizes were synth esised. The obtained nitrogen isotherms of these materials varied from a ''type I-like'' isotherm (small pore size) over a reversible type I V isotherm (intermediate pore size) to a typical type IV isotherm, whi ch shows pore condensation with hysteresis. Similar types of transitio n states and hysteresis curves are observed by H-1 nuclear magnetic re sonance (NMR) by monitoring the proton signal intensity of the mobile water molecules confined in the pores versus temperature. The consiste ncy observed between the two methods makes H-1 NMR a valuable addition al technique for characterisation of mesoporous materials.