Sintesi e caratterizzazione di materiali mesoporosi: studio del loro comportamento cromatografico

This work was focused on the improvement of chromatographic performance of the hybrid mesoporous inorganic-organic material SBA- 15-COOH. Two ways have been followed: modification of morphology, synthesizing spherical particles of SBA and end-capping of free surface silanols, that can give interaction with the analites. Separation of alkali, alkaline earth and ammonia ions (Li+, NH4+, Na+, K+, Ca2+, Mg2+, Sr2+, Ba2+) and of heavy metals cations (Cd2+, Co2+, Fe2+, Fe3+, Ni2+, Cu2+, Zn2+) of environmental interest was investigated. The retention mechanism was studied through the modification of experimental conditions and chromatographic parameters (pH, ionic strength, eluent flow and composition); this allowed a comparison between new materials and not modified mesoporous material. We can assert, on the basis of results obtained, that the spherical material offers an improvement of chromatographic peak's symmetry values, while the ¿end-capped¿ material, in addition to symmetry rising, gives smaller values of peak's width and allow separation of Mg from the other metals under specific chromatographic conditions.