To Study the Role Of Emulsifying Agents In Stabilising the Emulsions Of Different Oils

Colloidal solutions in which both the dispersion medium and dispersed phase are liquids but present in unequal proportions are known as emulsions.

• Emulsion is prepared by shaking vigorously the mixture of two colloids.
• Emulsifiers or emulsifying agents are further added to stabilize the unstable emulsions. 
• Surfactants are also a type of emulsifier, which reduces the surface tension between a solid and liquid or between two liquids.

Keywords: Emulsions, Emulsifying Agents, Colloids, Dispersion medium, Liquids, Emulsifying Agent Example

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Aim

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To study the role of emulsifying agents in stabilizing the emulsions of various oils.

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Theory

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An emulsion is a colloidal solution with liquid dispersed phase and dispersion medium. Distinction between dispersion and dispersed medium is done on the basis of the proportions.

• The dispersion medium is in a larger quantity and the dispersed phase is present in a smaller proportion. 
• The vigorous mixing of oil and water results into change in texture and formation of unstable emulsion which is further stabilized by addind soap solution. 
• The solution of soap is always added in an appropriate amount for better results and effective stabilization. 

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Materials Required

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• Test tube
• Glass rod
• 5g of Soap or detergent
• Stopwatch
• 5 Droppers
• 6 Test tubes
• 10mL each of Machine oil, Mustard oil, linseed oil, and castor oil

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Procedure

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• Place a test tube and pour 10ml of distilled water along with 1g of detergent for dissolution.
• Mark the test tubes with “a”, “b”, “c”, “d”, & “e” and add 5 ml of distilled water in each test tubes.
• Add 10 drops each of mustard oil, linseed oil, castor oil & machine oil  in b,c,d,& e test tubes. 
• Hold the test tube “b” firmly in your hand and shake it for 5 minutes.
• Note the time taken to separate the two layers.
• Now, Follow the same procedure with all other test tubes – c, d and e.

Different Samples in Different Test Tube

• Finally add two drops of already prepared soap or any detergent solution in ech test tubes and shake them for 5 minutes each,
• To record the results, make a table and note the parameters given below once the procedure is completed. 

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Precautions

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• Always mix soap or detergent solution in equal quantities. 
• Reducing unnecessary error when recording time.
• After observing different layers the test tube should be shaken at different time intervals.

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Things to Remember

• Preparations of emulsions are done by shaking vigourously the mixture of two colloids.
• Emulsions are generally unstable, hence an extra substance is added to stabilize it which are also called emulsifiers or emulsifying agents
• Emulsions can be divided into two types- Emulsion of oil in water (o/w), Emulsion of water in oil (w/o).
• Emulsifier increases the kinetic stability of a mixture and refrains the unmixable compounds from separating.
• Disinfectants such as Dettol, Savlon are emulsions of oil-in-water type of emulsions on mixing with water.

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