Study on the influence of cellulose microfiber in o/w emulsions stabilized with tween 80, ethanol, and castor oil

Abstract

Emulsions are thermodynamically unstable systems homogenized by emulsifiers, amphiphilic agents that interacts with both immiscible substances. In the industry field, these agents are commonly synthetics, causing risk to human health and environment. The cellulose microfibers (CMF) is an abundant material, versatile and low toxicity with emulsifying properties due to its capacity to form a 3d network and amphiphilic behavior. However, its versatility can be tricking when inserted into an emulsion due to its complex interactions with other materials. This work studied the influence of CMF, from a commercial brand, in an oil-in-water system compound with castor oil, tween 80, ethanol and water. The experiment was designed by factorial design, and the formulations were characterized by visual stability analysis, microstructure, diameter droplets, ionic demand and structural stability. Results have shown an ideal proportion of 25 % CMF dispersion to get stable macroemulsion for 7 days. Its presence preserved the droplets pattern formed by tween 80 and ethanol, making a macroemulsion, besides acting as a thickener that not only modifies, but also intensifies the viscoelastic behavior of the emulsion with the increase of quantity of CMF, from 0.25 % to 0.45 %. The ionic demand showed CMF as an anionic material and tween 80 and ethanol, as non-ionic. The stability was achieved due to the tridimensional CMF network formed by the interaction with the quantities of tween 80 and ethanol.