Fabrication Of Yolk-shell Hollow Microspheres And Switchable Pickering Emulsions

Because hollow materials have characterization of high specific area, low density, highadsorbing ability and being able to adsorbing active composition, they have broad potentialapplications ranging from catalysis, bioseparation technology, tissue engineering, solar cell toreaction separation fields. Magnetic materials have characterization of of transferring abilityto offer specific target, magnetic responsive imaging, separation and recovery, so they havebeen widely used in life science. Hollow microspheres with magnetic cores have been used indrug and genes delivery, biomedicine and biosensor.Solid particles can exist at the interface between two phases like the surfactants, so theycan behave the same way as surfactants. The emulsion consists of solid particles instead ofsurfactants can be applied to food, cosmetics and medicine field.Based on the above ideas, we work on the following items:1. We synthesized porous and hollow SiO2microspheres at high temperature based onSt ber method and the size and number of the hole on the sphere surface can be preciselycontrolled.2.To get the magnetic yolk-shell hollow spheres, Fe3O4particles were synthesized bythermal solvent method, then magnetic cores were encapsulated in SiO2by St ber method,finally SiO2were etched by high temperature.3. We used Fe3O4@SiO2composite materials as solid particles,the airflow of CO2and N2alternately change to change the hydrophilic and hydrophobic properties and gas couldregulate Pickering emulsion. The Pickering emulsion was tuned by changing magnetic field,too. Finally, the Pickering emulsion was synthesized by controlling magnetic field and gas.