Caracterización de emulsiones preparadas mediante un inversor de flujo helicoidal

Abstract

In the present work the effect of two emulsifiers in colloidal dispersion (oil / water) was studied using different preparation techniques. The emulsifiers analyzed were hydrophilic silica particles and sodium dodecyl sulfate. Both emulsifiers were previously dispersed using an ultrasonic bath and ultrasonic tip as preparation technique to evaluate the effect in the colloidal dispersion. According to the particle size distribution of each emulsifier, it was found that the ultrasonic tip offers more stability on aqueous dispersion because of the measurements reproducibility. The concentration effects of the silica particles and sodium dodecyl sulfate were studied measuring oil-water glass contact angle and oil-water interfacial tension. Samples were prepared using an ultrasonic tip, a coiled flow inverter and helical pipe. Experimental results suggest that silica particle concentration does not influence the interfacial tension and the contact angle in the oil-water system. The results also show that the interaction between surfactant and silica particle is affected by the mixing conditions during the colloidal dispersion process. Emulsions prepared with the ultrasonic tip show a strong interaction between both emulsifiers surfactant and silica particles, on the other hand, the coiled flow inverter and the helical pipe used under the laminar flow conditions show moderate and almost equal interaction between both emulsifiers according to droplet size distribution measures.