Nano-emulsion formation by low energy methods

Nano-Emulsion Formation by Low-Energy Methods and Functional Properties... 

In this chapter, nano-emulsion formation by low-energy emulsification methods, with special emphasis on phase inversion methods and their relation to surfactant phase behavior will be discussed first. This will be followed by an analysis of nano-emulsion functional characteristics. The relation with their structure is discussed regarding the applications in which they are relevant. Prior to discussing nano-emulsion functional characteristics, the main nano-emulsion destabilization mechanism, Ostwald ripening, is described. 

Forgiarini, A., Esquena, J., Gonzalez, C. and Solans, C. (2001) Formation of nano-emulsions by low-energy emulsification methods at constant temperature. Langmuir, 17 (7),... 

Sadurm, N., Solans, C., Azemar, N. and Garci a-Celma, M.J. (2005) Studies on the formation of O/W nano-emulsions, by low-energy emulsification methods, suitable for pharmaceutical aplications. Emulsion polymerization initiation of polymerization in monomer droplets., 26, 438-445. 

Caldero, G., Garcfa-Celma, M.J. and Solans, C. (2011) Formation of polymeric nano-emulsions by a low-energy method and their use for nanoparticle preparation. Journal of Colloid and Interface Science, 353, 406-411. 

In this chapter, different methods for nano-emulsion formation, with special emphasis on low-energy emulsification methods, are discussed in Section 11. This is followed by a description of nano-emulsion stability (Section 111). Finally, the most relevant applications of nano-emulsions are reviewed... 

Considering only mechanical energy aspects, nano-emulsion formation should be considerably costly. However, it is well known that by taking advantage of the physicochemical properties of the system, dispersions can be produced almost spontaneously [3,6,14]. This is the case with the so-called low-energy emulsification methods that are described next. In practice, the two types of methods are often combined. 

N. Uson, MJ. Garcia, and C. Solans Formation of Water-in-Oil (W/O) Nano-Emulsions in a Water/Mixed Non-Ionic Surfactant/Oil Systems Prepared by a Low-Energy Emulsification Method. Colloid and Surfaces A Physicochem. Eng. Aspects 250, 415 (2004). 

Uson, N., Garcia, M.J., and Solans, C., Formation of water-in-oil (W/O) nano-emulsions in a water/ mixed non-ionic surfactant/oil systems prepared by a low-energy emnlsification method, Colloids Surf. A Physicochem. Eng. Aspects, 2004, 250(1-3), 415 21. 

Nano-emulsions are defined as a class of emulsions with uniform and extremely small droplet size (typically in the range 20-500 nm). The formation of kinetically stable liquid/hquid dispersions of such small sizes is of great interest from fundamental and applied viewpoints. In this review, nanoemulsion formation, with special emphasis on low-energy emulsification methods, is first discussed. This is followed by a description of nano-emulsion properties, focusing on their kinetic stability. Finally, relevant industrial applications of nano-emulsions in the preparation of latex particles, in personal-care formulations, and as drug dehvery systems are reported. 

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