Emulsion Stability Measurements and Drop Size Determination

Emulsion Stability Measurements and Drop Size Determination 

The emulsion stability was measured by two different techniques, at rest by Turbiscan analysis and under intense shear conditions by rheometer, with the simultaneous application of an electric field to enhance coalescence. 

To detect any instability, the viscosities of all emulsions were first monitored at 40 °C, under the influence of shear only for 130 s. After 130 s a voltage was applied and increased from 0 to 1000 V at a rate of 4 V s , corresponding to an electric field of about 8.8kVcm reached in 250 s. Short circuit limited the maximum value to 6kVcm .  

To describe the stability of the emulsions in terms of the change in viscosity we introduced an adimensional parameter called the viscosity ratio. The viscosity ratio was defined according to Equation 12.1, where t i is the viscosity before and 2 that after the application of the electric field  

The procedure was validated by comparison with the dewatering efficiency measured by Karl-Fischer titration. The dewatering efficiency was calculated as shown in Equation 12.2, where 1 and 2 denote the water content before and after the application of the electric field  

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