In this project we will study the synthesis, characterization and potential environmental and analytical applications of pure and modified highly ordered mesoporous silica materials having cubic 3D structure, with high thermal and hydrothermal stability. The silica FDU-1 is prepared in strongly acidic media using tetraethylorthosilicate (TEOS) as the silica source. Triblock copolymers, B50-6600 (EO39BO47EO39) and Vorasurf 504® (PEO-PBO-PEO), will be used as template. A first modification will be made, using humic acid in proportions previously established, to assemble a pre-concentration column for retention of mercury ions. The surface modification by Grafting will be made using APMES and APTES as silylant agents. These modified silica materials will be studied for adsorption of Cu2+, Pb2+ and Cd2+ ions, in comparison with the pristine FDU-1 silica. Modified silica will be prepared by incorporating crystalline zeolites on the silica walls (FDU-1/ZSM-5) aiming adsorption of triazines, as well as to perform degradation studies of these aromatic compounds exploring the catalytic properties of the modified silica. Synthesis and characterization of hybrid organic-inorganic periodic mesoporous structures (PMOs) will be made using the triblock copolymer Vorasurf 504® in strongly acidic media, followed by hydrothermal treatment in a microwave oven. This material will be used to assess the adsorption capacity of Cd2+, Cu2+, Pb2+ and Hg2+ ions. The gels of synthesis will be submitted to hydrothermal treatment in oven or microwave oven, and then the samples will be calcinated in atmosphere of N2 and air, or submitted to solvent extraction. The materials will be characterized by thermogravimetry/derivative thermogravimetry (TG/DTG), elemental analysis (EA), infrared spectroscopy absorption (IR), small angle X-ray diffraction (SAXRD), transmission electron microscopy (TEM), N2 adsorption isotherms. The determinations of ions and organic compounds will be carried out by voltammetry methods and/or automated sequential injection chromatography.
News published in Agência FAPESP Newsletter about the scholarship: