Winsor Type III microemulsion
Out of three microemulsion types, Winsor Type III microemulsion reflects the most favorable condition for surfactant flooding [38].
What is microemulsion used for?
Microemulsions have many commercially important uses: Water-in-oil microemulsions for some dry cleaning processes. Floor polishers and cleaners. Personal care products.
What is emulsion and microemulsion?
Emulsions and microemulsions are both stable dispersions of oil-in-water or water-in-oil. Emulsions are stable dispersions of immiscible liquids, but they are not thermodynamically stable. We say that they are kinetically stable. These type of dispersions are sometimes called macroemulsions.
What is microemulsion polymerization process?
Definition. Microemulsion polymerization is defined as polymerization involving a radical chain propagation reaction with vinyl monomers in one phase of a microemulsion, and the produced polymer colloid is denoted as latex.
What is microemulsion flooding?
One of the effective methods in recovering the unswept reserves is chemical flooding. Microemulsion flooding is an alternative for surfactant flooding in a chemical-enhanced oil recovery method and can entirely sweep the remaining oil in porous media.
Why co-surfactant is needed in forming the microemulsion?
The roles of a co-surfactant are to increase the fluidity of the interface, destroy liquid crystalline or gel structure which would prevent the formation of the microemulsion and adjust the HLB value and spontaneous curvature of the interface by changing surfactant partitioning characteristic [4].
What are the advantages of microemulsion?
Microemulsions have been proposed as drug delivery systems to enhance the absorption of drug across biological membranes (Majuru and Oyewumi, 2009). Some of microemulsions advantages include: (1) increased solubility and stability of drugs, and (2) ease and economical scale-up.
What is microemulsion method?
The microemulsion technique promises to be one of the versatile preparation method which enables to control the particle properties such as mechanisms of particle size control, geometry, morphology, homogeneity and surface area.
Is a microemulsion a solution?
A microemulsion is a thermodynamically stable fluid that differs from kinetically stable emulsions, which will separate into oil and water over time. The particle size of microemulsions ranges from about 10–300 nm. Because of this small particle size, microemulsions appear as clear or translucent solutions.
Is microemulsion transparent?
Microemulsions are stable transparent dispersions of water and oil (mixture of various hydrocarbons and olefins) and surfactant. They are prepared by simple mixing of the components and do not require specific preparation conditions.
What is microemulsion Slideshare?
Microemulsion is an isotropic mixture of oil, surfactant, Cosurfactant and drug. Upon mild agitation followed by dilution in aqueous media, such as gastrointestinal (GI) fluids, the systems can form fine oil in water (O/W) Microemulsions which usually have a droplet size less than 100 nm.
What is the difference between microemulsion and nanoemulsion?
In principle, a nanoemulsion could be formed from oil and water without using a surfactant. The major distinction between a nanoemulsion and a microemulsion is therefore their thermodynamic stability: nanoemulsions are thermodynamically unstable, whereas microemulsions are thermodynamically stable (see Section 2).
What are balanced bicontinuous microemulsions?
When the hydrophile-lipophile properties of the surfactant monolayer at the water/oil interface are balanced bicontinuous-type microemulsions are formed (Ho=O). Under these balanced conditions, Ho=O, maximum soluilization of water and oil with the minimum amount of surfactant is achieved.
What is the best surfactant for microemulsions?
Most of the basic studies on microemulsions have been made with standard surfactants such as polyoxyethyleneype nonionic surfactants, alkyl sulfates, quaternary amonium salts and dialkyl sulfosuccinates. The oils in these investigations were, generally, aliphatic or aromatic hydrocarbons.
What are the properties of surfactants?
3. Microemulsions. This chapter is devoted to another important property of surfactants, that of stabilization of water-oil films and formation of microemulsions. These are a special kind of colloidal dispersion that have attracted a great deal of attention because of their ability to solubilise otherwise insoluble materials.
How many types of microemulsions are there?
3.3.1 Predicting microemulsion type A well-known classification of microemulsions is that of Winsor [21] who identified four general types of phase equilibria: • Type I: the surfactant is preferentially soluble in water and oil-in-water (o/w) microemulsions form (Winsor I).
