Detergent : Basic detergents are surface active compound. The compound which get orient at the interface (Between water and air) and reduce interfacial tension/surface (The tendency of water of drawing the molecules from the surface towards the body is known as surface tension) are called active compound or detergent.

Or A substance that consists the removal of dirt. The removal is affected by emulsification or dissolution of the dirt particles and the substance normally has the power of suspending the dirt in cleaning liquid.

Classification : (Basis on ionic nature)

An-Ionic Detergent : When the detergents are ionized into anions and cations but the anion is the dominating ion in the solution. Therefore the surfactant is called an anionic surfactant. e.g, Soap.

When sodium-stearate is dissolved in water, it ionizes as follows:

CH₃(CH₂)₁₆COONa —————-à CH₃(CH₂)₁-COO^– + Na⁺

Among the ions, anions CH₃(CH₂)₁₆COO^– is comparatively very large to sodium ion. So anion acts as dominating ion here. This sodium-stearate is called anionic-stearate.

Cationic Detergent:  Ionic surface active agents which produce cation as dominating ion when dissolved in water is called Cationic detergent. e;g Catyle Pyridinium Chloride. When Catyle Pyridinium Chloride is dissolved in water it consists as follows ……

Among two ions cation is very large compound to the chloride ion. Therefore cation behaves as a dominating ion in case of cationic surface active agent.

Non Ionic Detergent : Surface active agent which are soluble in water and get oriented at the surface of the solution and reduce when dissolve in water hence they are called “Non-Ionic detergent”

For example, when one mole of stearic Acid is condensed with six moles of Ethylene oxide a poly-ethene is formed

CH₃(CH₂)₁₆-COOH + 6 –{CH₂-O-CH₂}- === CH₃(CH₂)₁₆-COO(CH₂-CH₂-O)₆H

Amphoteric Detergent: Detergent when dissolved in water, ionize and produce large segment carrying both anionic and cationic ions (These Segments are called Zwitter ions). Thus amino carboxylic acids in which amino and carboxylic groups are present at the molecular chain ends dissolved in water to give zwitter ions.

H₂N(CH₂)_n-COOH ———-(H₂O)—à H₃N⁺(CH₂)_n-COO^–

Special Characteristics :

• • In Alkaline solution : P^H>7 (They behave like anionic Detergent )
  • When Acidic solution : P^H
  • When Neutral solution: P^H= 7 ( They behave like non-ionic Detergent)
  • Amphoteric surface active agent possess affinity towards wool and cellulose fibers.
  • They have lubricating properties.

Advantages of Non-Ionic detergent :

• • • They are available in liquid form. Their lack of affinity for textile fibers make them easily washable from textile mtl.
    • Stable over a wide range of p^H
    • Being non ionic in nature, they are compatible with many dyes and surfactants and they may be used in many formations.

Disadvantages of Non-Ionic Detergent:

• • • Sparingly / Partially soluble in hot water
    • Temporary nature
    • They cause too much formation

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