Synthesis, Characterization And Application Of Functionalized Mesoporous Silicas

Functionalized mesoporous materials show a large BET surface area, controllable distributed pore sizes and a pore arrangement, thermal and mechanical stability, and featuring high functionality. These materials are known to be promising candidates for the use in electronic, chemical and biochnological industries, and biomedical fields. Resecently, the development of functionalized mesoporous matericals for adsorption the heavy metal ions has generated considerable interst of many researchers. In this thesis, we first state the synthesis, characterization and adsorption properties of amino-functionalized mesoporous silicas. Subsequently, we report the synthesis and application of nanoscale Fe/Ni. The main research work is as follows:1. The mesoporous silicas has been prepared by tetraethoxysilane (TEOS) using oil-in-water microemulsion template in the presence of cetyltrimethylammonium bromide (CTAB, as structure-directing agent) and 1,3,5-trimethylbenzene (TMB, as oil phase). 3-Aminopropyl-triethoxysilane (ATES) was then added onto the interior surface via post-synthesis grafting. The prepared materials were characterized by SEM, XRD, FT—IR and nitrogen sorption. The results indicate that the amino-functionalized mesoporous silicas have not any long range ordering structure, whose diameters ranging from 1.5 to 7 nm (mean pore size: 3.3 nm) and the surface area is up to 562 m²/g. The animo functiomal groups have been successfully boned to the interior mesoporous surfaces.2. The study on the absorption capacity of Cr⁶⁺ showed that the amino groups played a main role to Cr⁶⁺ immobilization, the most absorption capacity can up to 2.32mM/g. The react balance time no more than 10 minutes; The adsorption capacity can be obviously improved by reducing pH of the solution. In addition, adsorbed Cr⁶⁺ can be readily recovered and re-utilized repeatedly through simple acid (HCL) treatment, the recycle is more than 90% of the initial activity. The metal ion adsorption capacity and reusability of the material makes it promising adsorbents for wastewater cleanup.3. Nanoscale Fe/Ni via wet chemistry was presented with mesoporous silica what has been prepared by oil-in-water microemulsion template. The materials have been characterized bySEM, TEM and XPS. The results demonstrated that nanoscale Fe/Ni alloy distributed on the...