Process For Reducing Sizes Of Emulsion Droplets

Summary

UCLA researchers in the Department of Chemistry and Biochemistry have developed a novel method of reducing sizes of droplets in multiple emulsion systems.

Background

The process of extreme emulsification is used to make nanoscale emulsion droplets (radii <100 nm) by imposing an extreme flow using a high-pressure microfluidic device or an acoustic or ultrasonic device. Strong viscous flows around the larger droplets stretch out the droplets, and capillary instability driven by the interfacial tension between the two liquid phases causes the stretched droplets to break up into smaller droplets. Extreme emulsification process using low concentration of surfactant typically produces oil-in-water nanoemulsions with droplets that have radii in the range of 40 nm to 100 nm. A significant amount of surfactant must be used, with additional cost, in order to make nanoemulsions with droplets that have radii as small as 15 nm.

Innovation

Researchers at UCLA have developed a more economical method of reducing droplet sizes and controlling droplet compositions in emulsions and nanoemulsions without significantly increasing the amount of surfactant during the process. This technology can be used to reduce droplet sizes in oil-in-water nanoemulsion systems, water-in-oil emulsion systems, water-in-oil nanoemulsion systems, oil-in-(immiscible oil) emulsion systems, and oil-in-(immiscible oil) nanoemulsion systems. Using this method, the UCLA researchers have successfully created nanoscale emulsion droplets of less than 20 nm in an oil-in-water nanoemulsion system. This technology provides possibilities for production of nanoscale emulsion droplets containing a wide variety of dispersed materials (i.e. polymers and biopolymers, nanoparticles, small molecules) that are amenable to nanostructured encapsulation applications in foods, cosmetics, drug delivery and beyond.

Applications

• Drug delivery applications in pharmaceuticals 
• Delivery of active constituents in cosmetic products 
• Delivery of reactive molecules 
• Delivery of water-soluble, amphiphilic molecules 
• Applications in food technology

Advantages

• Better control of droplet size distribution and composition
• Cheaper than typical extreme emulsification methods to produce nanoemulsions with droplets that have similar radii

State Of Development

The principle of this process has been reduced to practice. An economically feasible working device is under development.

Related Materials

• T.G. Mason, J.N. Wilking, K. Meleson, C.B. Chang, and S.M. Graves, Nanoemulsions: formation, structure, and physical properties, Journal of Physics: Condensed Matter (2006).
• T.G. Mason, M.D. Lacasse, D. Levine, G.S. Grest, J. Bibette, and D.A. Weitz, Osmotic pressure and viscoelastic shear moduli of monodisperse emulsions, Physical Review E (1997).

Patent Status