Abstract
The preparation of core-shell particles attracts a lot of attention in recent years, because core-shell particles own many advantages over sample particles. For example, one can apply different surface materials to adjust the physical, chemical or optoelectronic properties of plain particles.In this thesis, we try to prepare smooth-surface core-shell particles via layer-by-layer coating of reverse micelle nanoparticles with polyelectrolytes. First, we adsorb a layer of PAH on the surface of silica to change the surface property from hydrophilic to hydrophobic. The reverse micelle nanoparticles are adsorbed by hydrophilic force. Then we adsorb PSS on the surface of particles coated with reverse micelle nanoparticles to help next adsorption of reverse micelle nanoparticles and repeat the process until the desired thickness of shell achieved. Finally, we calcine them at suitable temperatures to get core-shell particles of smooth surface.According to EDS, UV-Vis and PL measurement, the characteristic peaks of silver, zinc sulfide, cadmium sulfide and titanium dioxide are observed, so these materials are successfully coated on the surface of silica particles. And from SEM pictures, we can see the shell is smooth. Besides, we also find the zeta potentials and dissolution rates are very different between core-shell particles and plain silica particles. These phenomena also give evidence for formation of core-shell particles.Finally, we use the adsorption cycle number and relative concentration of silica particles to reverse micelle nanoparticles to control the thickness of shell. According to EDS and UV-Vis measurement, we conclude the amount of silver increases when adsorption cycle number increases or relative concentration of silica particles to reverse micelle nanoparticles decreases.