Preparation, Characterization, and Rheological Behavior of O/W and W/O Non-Newtonian Emulsions using surface-modified Nano-Silica and Non-Ionic surfactant

Document Type : Original Article

Authors

Egyptian Petroleum Research Institute

Abstract

This paper used rice husk residues to extract silica and turn it into a liquid sodium silicate product by sodium hydroxide. The silica structure was formed by utilizing a Pluronic 123 surfactant in acidic media to produce silica with a controlled and medium porosity. The silica surface was grafted with (3-aminopropyl)triethoxysilane compound and then reacted with 1,3-propane sultone to produce silica capped with sulfonate groups. HSO3CF3 was used to exchange the prepared material’s counter ion for producing a highly acidic catalyst. The resulting catalyst was identified by various techniques, including HRTEM, XRD, BET, and FTIR. The results proved that the mesoporous materials had a surface area close to 769 m2/g, and after making the modifications, the surface area reached 185 m2/g. The catalyst was exploited in the preparation of 1-(2-hydroxyethoxy)-nonadecan-2-one compound, where it was obtained with a percentage close to 99.8% at a temperature of 140 °C and a catalytic amount of 8%. The resulting compound, 1-(2-hydroxyethoxy)-nonadecan-2-one, was mixed with sodium dodecyl sulfate to prepare oil in water emulsions. The results proved that the emulsion is stable for a period of up to 18 hours, and it depends on the percentage of oil in the emulsion. Oil’s viscosity in water emulsion has greatly improved compared to water in oil emulsion stabilized with amide product attached to mesoporous silica. Several rheological models have been assigned to the description of the behavior of non-Newtonian emulsion.

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