A novel formulation of the pickering emulsion stabilized with silica nanoparticles and its thermal resistance at high temperatures

Stabilization of emulsions with solid particles can be used in several fields of oil and gas industry because of their higher stability. Solid particles should be amphiphilic to be able to make Pickering emulsions. This goal is achieved by using surfactants at low concentrations. Oil-in-water (o/w) emulsions are usually stabilized by surfactant but show poor thermal stability. This problem limits their applications at high-temperature conditions. In this study, a novel formulation for o/w stabilized emulsion by using silica nanoparticles and the nonionic surfactant is investigated for the formulation of thermally stable Pickering emulsion. The experiments performed on this Pickering emulsion formula showed higher thermal stability than conventional emulsions. The optimum wettability was found for DME surfactant and silica nanoparticles, consequently, in that region; Pickering emulsion showed the highest stability. Rheological changes were evaluated versus variation in surfactant concentration, silica concentration and pH. Scanning electron microscopy images approved the existence of a rigid layer of nanoparticle at the oil-water interface. Finally, the results show this type of emulsion remains stable in harsh conditions and allows the system to reach its optimum rheology without adding any further additives.