Emulsion Essay

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Emulsions are an example of colloids composed of tiny particles suspended in another immiscible (unmixable) material. An emulsion is a suspension of two liquids that usually do not mix together. These liquids that do not mix are said to be immiscible. An example would be oil and water. If you mix oil and water and shake them a cloudy suspension is formed. Let the mixture rest and the oil and water will separate. An emulsifying agent (emulsifier) is any substance that keeps the parts of an emulsion mixed together. For example if we mix oil and water a suspension will form that over time separates. But now, if we add a few drops and shake the mixture the oil and water will stay mixed much longer. “The colloidal systems in which fine droplets of one liquid are dispersed in another liquid are called emulsions the two liquids otherwise being mutually immiscible.” or “Emulsion are the colloidal solutions in which both the dispersed phase and the dispersion medium are liquids.” A good example of an emulsion is milk in which fat globules are dispersed in water. The size of the emulsified globules is generally of the order of 10–6 m. Emulsion resemble lyophobic sols in some properties. CHARACTERISTICS: Emulsions tend to have a cloudy appearance, as a result of the scattering of light. As light passes through the emulsion, it is scattered by the many interfaces (boundaries) between the different phases (such as water and oil).In addition, emulsions are unstable and do not form spontaneously. (i) Emulsions show all the characteristic properties of colloidal solution such as Brownian movement, Tyndall effect, electrophoresis etc. (ii) These are coagulated by the addition of electrolytes containing polyvalent metal ions indicating the negative charge on the globules. (iii) The size of the dispersed particles in emulsions in larger than those in the sols. It ranges
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