In the laboratory scale, synthesized silica has become a promising material for many applications, such as the delivery system for drugs, sensor system for the detection of analytes (via adsorption) and as the catalytic system. With the help of surfactants or polymers it is possible to prepare SiO2 particles with a well-defined porous structure. Pore tunnels have diameter between 2 nm and 50 nm. According to IUPAC nomenclature they are called mesoporous materials. With further modifications, organic functional groups can be covalently bound to the surface of mesoporous SiO2, thereby changing the SiO2 properties and functionalizing the surface of the material for a specific purpose. The process of attaching new functional groups to the surface of a material is called functionalization. The modification of SiO2 is not straightforward and simple, as it is influenced by many parameters. Unambigous characterization is also hindered by inhomogeneity of the surface of the synthesized material.
The purpose of my master's thesis was synthesis of mesoporous SiO2 particles and further systematic modification of it’s surface with different organosilane reagents. In this way, amine, thiol, ethyl or phenyl groups were covalently bound to the SiO2 surface. Functionalized mesoporous SiO2 was characterized by nitrogen sorption, infrared spectroscopy, FE-SEM and TG/DTG measurements. The ability of adsorption of dye molecules to the SiO2 surface was evaluated by measuring the amount of dye adsorbed with the use of UV-Vis spectroscopy. Obtained properties of the modified SiO2 materials were compared and correlated with modification parameters.
The aim of the research in the master's thesis was to evaluate the influence of modification parameters and the choice of organosilane reagent on the properties of the final product.
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