A colloidal solution formed between two immiscible liquids is known as Emulsions.There are two types of emulsions.They are oil-in-water emulsions & water-in-oil emulsions.
Milk & vanishing cream are examples of oil-in-water emulsions.They contain small amounts of oil dispersed in water.
Butter & ice creams are examples of water-in-oil emulsions.They contain small amounts of water dispersed in oil.
How can we make an emulsion
Emulsions are made by shaking the two liquids together.Keep it for a while & we can notice that the droplets join together & two layers separate.So inorder to make the emulsion stable, a substance called emulsifying agent or emulsifier is added during the shaking.For example, an emulsion is formed by shaking 1ml coconut oil,25ml water & a little soap solution.Here the emulsifier is soap solution.
Substance that stabilises an emulsion when added in small amounts prior to the
shaking of the immiscible liquids are known as emulsifying agents or emulsifiers.
Examples of emulsifying agents are Soap, gelatin & albumin.
Role of emulsifiers
Emulsifiers provide a protective coating to each droplet of the emulsion.The emulsifier is a polar substance & due to the same charge around the droplet, thay repel each other & donot join together.
Emulsion formation in everyday life
Cleansing action of soap
Earlier days for mining nitroglycerin based explosives were used for mining.They are very reactive and hazardous and also very sensitive. In recent times these explosives are substituted by emulsion explosives. Emulsion explosives are less sensitive than than earlier version of explosives. These emulsions are basically oil in water emulsions. Ammonium nitrate aqueous solution and fuel oil are emulsified by using emulsifiers.A power point presentation on explosives is attached for information.