Study On Pickering Emulsions Stabilized By Particles Synergy Between Layer Clay Minerals And Silica Or Calcium Carbonate

The layered structure of layered clay minerals could form three-dimensional network structure in dispersed phase,which could trap droplets between the network structure,resulting in preventing the aggregation and demulsification.This phenomenon is conducive to stabilization of Pickering emulsion.In this work,several typical clays including kaolinite,montmorillonite(Ca-MMT and Na-MMT),layered double hydroxide(MgAl-LDH and NiAl-LDH),silica and calcium carbonate were used as stabilizers.The Pickering emulsions were prepared by ultrasonication and shearing emulsification.The stability of emulsions was analyzed by analysis of emulsion status,emulsion viscosity and microscopy.The main work and conclusions are as follows:(1)Stability properties were studied for the Pickering emulsions stabilized using different concentrations of single layered clay minerals by controlling the oil-water ratio.When the concentration of clay minerals was less than 1%,the volume fraction of emulsion and the viscosity of the emulsion increased with the increase of the concentration.When the clay particle concentration is greater than 1%,the concentration has no prominent influence on the emulsion viscosity.High concentration leaded to emulsion flocculation phenomenon,resulting in the decrease of the volume of emulsion.With the increase of layer clay mineral content,the average diameter of emulsion droplets gradually decreased.When the content of layered clay minerals was 1%,the emulsion droplets were the most uniform.These results indicated that the Pickering emulsion was most stable when the concentration of clay particles was 1%.(2)Stability properties were studied for the Pickering emulsions stabilized using different proportion of silica and layered clays by controlling the oil-water ratio.When the mass ratio of layered clay minerals and silica ratio was 9:1,the emulsion droplet distributed evenly,and the emulsion volume the emulsion viscosity were higher compared with the Pickering emulsions stabilized by single layered clays;When silica concentration increased,the emulsion volume proportion decreased,but it is still higher than that stabilized by single clays.The concentration has no prominent influence on the emulsion viscosity,but the uniformity of emulsion droplets decreased.These results indicated that the Pickering emulsion was most stable when the mass ratio of clay minerals to silicon dioxide was 9:1.Pickering emulsion was batter stable than the concentration of clay particles was 1%.(3)Stability properties were studied for the Pickering emulsions stabilized using different proportion of calcium carbonate and layered clays by controlling the oil-water ratio.When the mass ratio of layered clay minerals and calcium carbonate ratio was 9:1,the emulsion droplet distributed evenly,and the emulsion volume the emulsion viscosity were higher compared with the Pickering emulsions stabilized using different proportion of silica and layered clays;When calcium carbonate concentration increased,the emulsion volume proportion decreased,but it is still higher than that stabilized using different proportion of silica and layered clays.The concentration has no prominent influence on the emulsion viscosity,but the uniformity of emulsion droplets decreased.These results indicated that the Pickering emulsion was most stable when the mass ratio of clay minerals to calcium carbonate was 9:1.Pickering emulsion was batter stable than using different proportion of silica and layered clays in this ratio.