Synthesis Of Functional Core/shell Materials Using The Template Of SiO₂ Particles

In recent years, there has been intense interest in the fabrication of core/shell materials inthe field of material science. Core-shell materials, often made up of a solid core surroundedby a well-defined shell layer, are known to exhibit unique and advanced properties oversingle-component nanoparticles, making them attractive for use in a wide range ofapplications, and are therefore of extensive scientific and technological interest. The structure,size, and composition of these particles can be easily altered in a controllable way to tailortheir magnetic, optical, mechanical, thermal, electrical, and catalytic properties. Thecore-shell particles can be used as a precursor form to produce hollow spheres or to lower thecost of precious materials by coating them on inexpensive cores. Nowadays, one of the mosteffective approachs to produce core-shell materials is hard template method. There are manymerits such as simplicity, high repeating ratio and being foreseeable for this method.In this article, monodispersed silica particles templates were produced by St?ber method. Inthe RB solution, the well-dispersed silica particles are used as the template, and the hydrolysisof TiCl4 leads to the formation of well-dispersed RB-doped SiO₂/TiO₂ compositemicrospheres with catalytic and fluorescent properties. The morphology and structure of theparticles were characterized by scanning electron microscopy and X-ray powder diffraction.Dye-leakage test and photocatalytic experiment of particles were also investigated.SiO₂/PPY core/shell and PPY hollow materials were prepared by the template of silicaparticles whose surface character was modified with MPS. From SEM and TEM images, itcan be seen that the SiO₂/PPY core/shell particles and PPY hollow particles are in sphericalshape and have uniform size distribution. The PPY hollow particles also exhibit regularspherical shape and uniform size. This indicates that the hollow PPY shells are stable whenthe silica cores were dissolved.Finally, we used CTAB, OÏ€-10 and AOT to modify the surface of SiO₂ particles and thenprepared SiO₂/PPY core/shell and PPY hollow materials, respectively. Combined with MPSmodifying the template, the modified mechanism of different modified agents was discussed.It is confirmed that the modified degree of silica particles using different modified agentsdecreased from MPS, CTAB, and OÏ€-10 to AOT. With the decreasing of modified degree, themorphology of composite particles and PPY hollow particles changed from uniform sphericalshape to unstable cracked spherical shape and PPY small nanoparticles.