Fabrication and factors of stabilization of pickering emulsion based on TiO₂-SA-Arg nanoparticles

Salicylate (SA) and arginine (Arg) were modified on the surface of nano TiO₂ by impregnation method, FT-IR, XRD, BET, TEM, dynamic light scattering(DLS), TG and contact angle measurement were employed to characterized the structures and properties of the modified particles. The results show that the modified particles are sheet mesoporous nanoparticles with mixed crystal structure. The particles have weakening hydrophilic surface and less reunion in water compared with the unmodified particles. The effect of emulsification time, the pH value and the electrolyte concentration of the aqueous phase, the amount of solid particles, the oil phase volume fraction and standing temperature on structure and stability of nitrobenzene/water emulsion of Pickering emulsion was studied. The results show that, the emulsion has the best stand stability when the pH value of aqueous phase is 3~5 or the electrolyte concentration is 0.05~0.2 mol/L; the creaming index of emulsion is increased with the solid particle concentration increasing; the phase inversion occurs when the oil phase volume fraction is 40%. The critical micelle concentration of solid particles (CMC) value was determined and the result shows that modified particles have similar amphiphilic properties of polymer.