Michael A. Henson Group

Integrated Product and Process Design for Emulsified Products

Oil-in-water emulsions have a wide variety of applications including cosmetics, creams, lotions, agricultural products, and hydrophobic compound encapsulation and delivery. In the foods industry, emulsions constitute numerous natural as well as processed products such as milk, butter, margarine, sauces and desserts. The drop size distribution affects several important emulsion properties including rheology, stability, texture and appearance. Emulsions are typically formed by low-shear mixing in an agitated vessel followed by processing in high-shear device such as a high pressure homogenizer to create drops in the targeted range. Due the lack of suitable predictive models, emulsified products are currently developed by combining a broad knowledge of previous product formulations with empirical scientific experimentation to create new formulations with desired properties.

The objective of this project is to perform homogenization experiments and develop population balance equation (PBE) models to predict the drop size distribution and enable more systematic design of emulsion formulations and processing conditions. Initial research was concentrated on the development and experimental validation of breakage-only PBE models in which low oil-to-surfactant ratios allowed drop coalescence to be neglected. Particular emphasis was placed on indentifying the relevant breakage mechanism and incorporating descriptions of multiple drop breakage. Our current work is focused expanding the applicability of the PBE models through the incorporation of drop coalescence and surfactant coverage.

Funding: Unilever, National Science Foundation

Student: Shashank Maindarkar (3rd year Ph.D. student), Magnum Lew (undergraduate student)

Collaborators: Hans Hoogland (Unilever), Surita Bhatia (UMass), Michael Malone (UMass) and Julian McClements (UMass)

Publications and Recent Presentations:

1. Raikar N., S. R. Bhatia, M. F. Malone and M. A. Henson, "Self-Similar Inverse Population Balance Modeling for Turbulently Prepared Batch Emulsions: Sensitivity to Measurement Errors," Chemical Engineering Science, 61 7421-7435 (2006). [PDF]
2. Raikar N., S. R. Bhatia, M. F. Malone and M. A. Henson, "Experimental Studies and Population Balance Equation Modeling of Emulsion Drop Breakage," Chemical Engineering Science, 64, 2433-2447 (2009). [PDF]
3. Raikar N. B., S. R. Bhatia, M. F. Malone, D. J. McClements, C. Almeida-Rivera, P. Bongers and M. A. Henson, "Prediction of Emulsion Drop Size Distributions with Population Balance Equation Models of Multiple Drop Breakage," Colloids and Surfaces A: Physicochemical and Engineering Aspects, 361, 96-108 (2010). [PDF]
4. Raikar, N. B., S. B. Bhatia, M. F. Malone, D. J. McClements and M. A. Henson, "Predicting the Effect of Pressure on the Drop Size Distributions of Homogenized Emulsions," Industrial Engineering and Chemistry Research, accepted for publication.