(750f) Multi-Scale Approach to the Design of Emulsions: Water-in-Oil and Oil-in-Water with Dispersed Phase Between 10% w/w and 30% w/w

A wide selection of products in food, pharmaceutical, cosmetic and oil industries are emulsions; therefore, they are constantly investigated in order to improve their properties and applications. Emulsion preparation process involves different factors such as process conditions, formulation and composition parameters and as a result of their combination, certain properties are achieved according to the level in which these factors are varied.

The multi-scale approach to the design of emulsions leads to a better comprehension of the effect of each factor and its relationship with the others through the analysis of the resulting measured properties in three different scales: macroscopic, microscopic and molecular.

The purpose of this investigation is to determine the relationship existing between the process conditions , the emulsion formulation and composition in the preparation of water-in-oil and oil-in-water emulsions containing low dispersed phase (between 10% w/w and 30% w/w) and non-ionic surfactants. The oil phase to be used is mineral oil, dodecane or decaline in order to study in each case the influence of the oil chemical structure and the non-ionic surfactant is a blend of Span 80 and Tween 20. The aqueous phase is deionized water.

The properties of the emulsions to be measured are: the rheological behavior as the macroscopic response, in both the steady state and oscillatory tests using a controlled stress rheometer (TA Instruments AR-G2), the particle size and distribution as the microscopic response, using a Malvern Instrument Model 3000 Mastersizer particle size analyzer and the near infrared spectroscopy as the molecular response, using a FOSS 5000 Smartprobe Analyzer.

The main process conditions studied are the impeller tip speed, tank and impeller geometry and fluid height which are linked by the measured energy required to prepare the emulsions. The analysis of the possible interactions is made by observing the effect of this added energy and the emulsion’s formulation and composition on the obtained properties evaluated in the macroscopic, microscopic and molecular responses. One possible interaction for example, is that it may exist a relationship between the impeller’s pumping capacity and the energy consumption for the preparation of the emulsions.