Nonaqueous Synthesis of Metal Oxide Nanoparticles and Their Surface Coating

This thesis mainly consists of two parts, the synthesis of several kinds of technologically interesting crystalline metal oxide nanoparticles via high temperature nonaqueous solution processes and the formation of core-shell structure metal oxide composites using some of these nanoparticles as the core with silica, titania or polymer as shell via a modified microemulsion approach. In the first part, the experimental procedures and characterization results of successful synthesis of crystalline iron oxide (Fe3O4) and indium oxide (In2O3) nanoparticles are reported. Those nanoparticles exhibit monodispersed particle size, high crystallinity and high dispersibility in non-polar solvents. The particle size can be tuned by the seed mediated growth and the particle shape can also be controlled by altering the capping ligand type and amount. The mixed bi-metal oxides such as cobalt iron oxide and lithium cobalt oxide will be discussed as well. In the second part, the synthesis and characterization of various surface coated metal oxides, including silica, titania and polymer coated nanocomposites are reported. The silica coating process is presented as a highlight of this part. By using a microemulsion system, core-shell structure silica coated iron oxide and indium oxide nanocomposites are successfully prepared. Furthermore, the thickness of the silica coating can be controlled from 2 nm to about 100 nm by adjusting the reaction agents of the micelle system. By extending the procedure, we will also discuss the titania and polymer coating preparation and characterization