Preparation And Emulsifying Properties Of Core-Shell Interfacially Active Composites

Core-shell solid emulsifier with unique textural properties exhibits high potential applications in intelligent Pickering emulsions and phase inversion. As a result, excellent performance Pickering emulsion demands emulsifiers with good interfacial activity. Therefore, how to modify the materials on the nanometer scale is the key technique. At the same time, the development of environment-responsive smart emulsions becomes another desirable theme.This thesises are concerned on the fabrication of series core-shell composites which have different surface properties and investigation of the emulsifying properties. First of all, the strategies of post-grafting and co-condensation were used to modify the surface. And then, the structure, composition, magnetic and wettability of the obtained emulsifiers were estimated by N2 physical adsorption, TEM, XRD, TEM, IR, TG, solid state NMR, element analysis, VSM and contact angle. Characterization results indicate that two composites both have core-shell structures and two organic functional groups have been successfully loaded onto the shell surface.In fact of the above results, the magnetic and mesoporous silica core-shell nanoparticles were used as stabilizer to prepare Pickering emulsions, and factors of the stability, composition, type and microstructures of the resultant emulsions were investigated. The studys of magnetic solid emulsifying performance demonstrate that the composites express excellent interfacial activity and highly emulsifying properties at the oil/water interface. The W/O emulsion is prepared with a small amount of magnetic materials, and it was found that preparing processes of composites determine the interfacial activity of emulsions and the properties of Pickering emulsion. Furthermore, mesoporous silica emulsifying performance results reveal that both O/W and W/O types of emulsions are prepared using the double functional composites. The polarity of organic solvents has no obvious effects on the stability of emulsion, but the stability of the emulsion is enhanced through increasing the concentration of the electrolyte in water phase. Moreover, solid emulsifiers with the amphiphilic nature of the particle surface have a better emulsion stability properties than single solid emulsifiers.