Biodiesel is a vegetable oil, such as soybean oil, that has been chemically modified through a transesterification reaction to reduce its viscosity. As it turns out, microemulsification of vegetable oils can reduce viscosity without the need for the transesterification reaction. This would save time and allow more of the raw material to be used as fuel. However, Sabatini notes that the research is still in its early stages. Although humans have been making emulsions for hundreds, if not thousands, of years, we are only now beginning to appreciate their diverse applications in many fields.
Complex emulsions, such as microemulsions and multilayer emulsions, promise to further expand the repertoire of applications, particularly in emerging areas such as functional foods and biodiesel production.
Now if only we could find an emulsifier for that difficult coworker. She has a Ph. The terms surfactant, emulsifier, and detergent are often used interchangeably, but there are distinctions. Surfactant is the broadest term: Both emulsifiers and detergents are surfactants. Surfactants, or surface-active agents , are compounds that lower the surface tension between two liquids or between a liquid and a solid.
Surfactants are amphiphilic, meaning that they contain hydrophilic water-loving head groups and hydrophobic water-hating, or oil-loving tails.
Surfactants adsorb at the interface between oil and water, thereby decreasing the surface tension. An emulsifier is a surfactant that stabilizes emulsions. Emulsifiers coat droplets within an emulsion and prevent them from coming together, or coalescing. An emulsion is a mixture of two or more liquids, with or without an emulsifier, that are normally immiscible. A suspension is a solid dispersed in a liquid. The particles are large enough for sedimentation.
The session, which will be held on Wednesday, May 7, from —5 p. A complete list of presentations. In This Section Previous Next. April After reading this article, you will understand: the basic science of emulsions; how formulators choose which emulsifier to use for a particular emulsion; how emulsifiers are used in foods, nutraceuticals, personal and home care products, industrial lubricants, environmental technologies, biofuels, and other applications.
How to choose the right emulsifier How do product formulators choose which emulsifier to use for a particular emulsion? Macro- and microemulsions Increasingly, formulators are interested in making microemulsions, which offer greater stability than conventional macroemulsions. Home care Many household cleaners and laundry detergents contain surfactants that emulsify oily dirt particles so that they can be diluted and washed away.
Environmental technologies Emulsions and microemulsions have been applied to environmental technologies such as subsurface remediation and biofuel production. A detergent is a surfactant that has cleaning properties in dilute solutions. Likewise, the terms emulsion, suspension, and foam are sometimes confused. A foam is a substance in which gas bubbles are suspended in a liquid.
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Try again? Cited by. Download options Please wait Editors: Tharwat Tadros. Contents Search. Emulsion Stabilization. How to cite. This is a preview of subscription content, log in to check access. Langmuir — Google Scholar. Energy Fuel — Google Scholar. Polym Gels —17 Google Scholar. Cellulose — Google Scholar. Andresen M, Stenius P Water-in-oil emulsions stabilized by hydrophobized microfibrillated cellulose. Pickering emulsions stabilised by Laponite clay particles.
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Dongming L Coalescence between small bubbles: effects of surface tension gradient and surface viscosities. J Mater Sci —33 Google Scholar. A light, x-ray, and neutron scattering investigation. Fan Y, Simon S, Sjoblom J Interfacial shear rheology of asphaltenes at oil—water interface and its relation to emulsion stability: influence of concentration, solvent aromaticity and nonionic surfactant.
Fenistein D, Barre L Experimental measurement of the mass distribution of petroleum asphaltene aggregates using ultracentrifugation and small-angle X-ray scattering. Fuel — Google Scholar. Fontell K, Ceglie A, Lindman B, Ninham B Some observations on phase diagrams and structure in binary and ternary systems of didodecyldimethylammonium bromide. Take a test tube. Put 10mL of distilled water and dissolve 1g of detergent in it.
Take 4 more test tubes and label them as B, C, D, E. Add 5mL distilled water in each test tube. Put 10 drops of mustard oil in the test tube B, 10 drops of linseed oil in C, 10 drops of castor oil in D, and 10 drops of machine oil in test tube E. Take the test tube B in your hand and shake it vigorously for 5 minutes and keep it aside in a test tube Stand.
Start your stopwatch to record the time required to separate the two layers. Follow the same process with other test tubes — C, D and E. Add two drops of soap solution or detergent which were prepared in the test tube A into each test tube. Shake each test tube for 5 minutes. And record the time taken to separate two layers. Make a table as given below and record the results :.
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