Detergent
Any material which enhances the cleaning effect of water is called detergents. The term detergents are commonly used for synthetic products, used for cleaning purposes. Synthetic detergents are better cleaning agents than soaps. Synthetic detergents are also called syndets. Syndets have already replaced about 80% of the world demand of soap. Soaps are the sodium and potassium salts of long chain fatty acid where as detergents contain sodium or potassium salts of alkali sulphonated acid or aryl sulphonated acid in their composition. Non-aqueous detergents have also been developed. These are made by making the use of cleaning action of organic solvents. These are used for dry cleaning purposes. Detergents are very complex mixture of many substances; these are so selected to play an particular cleaning action. They are more effective in hard water then soap. Composition of Detergents: Detergents vary in their composition, depending upon its cleaning task. Different type of detergents is available in the market, which are different from each other in their composition. But common composition which must be present in each detergent is given below. 1 2
3
Surfactants & Suds Regulator 15-20% Builders Auxiliary agents 30-40% 30% (Additives)
Surfactants: It means any material that affects the surface tension of water when it is dissolved in water solution. Actually surfactant mean surface active agent. Soap is the material which has this property but the term surfactant is only used for organic derivative. Such as sodium salt of higher molecular weight . E.g. alkyl sulphonate & sulphates. Surfactants are actually responsible for the primary cleaning and washing action. Surfactants are long chain molecules with one end insoluble nonpolar hydrocarbon while the other end is water soluble. Types of Surfactants.
1 2 3 4 5
An-Ionic Surfactants (-So3- , -OSo3- ) Cat-Ionic Surfactants (-N(CH3)3+, -C5H5N+) Non-Ionic Surfactant (-O(CH2-CH2)nOH Zwitter Ionic Surfactant (-N+(CH3)3(C2H2)COOSemi-Polar Surfactant N(CH3)-O
The an-ionic, cat-ionic and non-ionic surfactants are commonly used detergents. An-Ionic Surfactants: Active part of this surfactant is ively charged so it gives in solution surface active ions having negative charge. e.g. Alkyl Benzine sulphonate, Alkyl Sulphate, Alkyl Benzine ether sulphonate. Cat-ionic Surfactants: The active part of this surfactant is positively charged so it gives in solution surface active ions having positively charge. Quartnery Ammonium compound such as pyladin derivative and amine. Most important examples are. 1 2 3 Quartnery Tri-methyl alkyl ammonium ethyl Cetyl tri-methyl ammonium bromide Di-alkyl-Di-methyl ammonium chaloride
These are not good detergent having weak detergent power but having good lubrication and germicide. These are not household detergents. Non-Ionic Surfactants; These are more excellent detergents having good detergent power. These are good emulsifying agent. These are useful in automatic drum type cloth washing. Non-ionic detergents are more effective then an-ionic in removing soil at low temperature. It is useful for laundry work. For synthetic fiber these are also more effective at removing body soil.
1 2 3
Alkyl Ethylene oxide derivatives Aryl Ethylene oxide derivative Aliphatic poly hydric alcohol ester
Suds Regulator: These are the ingredients often used with surfactants are known as suds regulator. These are hydrophobic materials responsible for suds action. These are necessarily used with surfactants for efficient work of cleaning in washing machine. These materials have no chemical relationship and often specific for certain surfactants. These are act as stabilizer and suppressor.
Washing Action of Soap and Detergents: Washing action of soap and detergents are very similar. It consist of these steps.
1
Wetting the dirty surface thoroughly by soap water and detergents.
2 Removing the dirt from the surface of the article. 3 Maintaining the dirt in the solution of detergent and soap.
Builders:
These are the chemicals which boots up detergent power are called builders. These are especially used in detergent. These are exclusively complex phosphate such as sodium tri-poly phosphate they also prevent the deposition of the soil from wash water on fabric complex phosphate is the key of good detergents. Rapid rise in the acceptance of the detergents is mostly due to the action of complex phosphate.
These are commonly sodium tri-poly phosphate, tetra sodium pyrophosphate. These are actually water softener and reduce the hardness of water as well.
Additives:
Additives are also used in the formulation of detergents but they must be in small quantity. i.e. 3% to 4% or less, there are different types of chemicals which are use as additives for different purposes.
Corrosion In-Habitor:
Such as sodium silicates, protect metal and washer part from the action of detergent water. Anti-Red positing Agents: Protects the soil to re-deposit on fabric from wash water. CMC (carbonyl Methyl Cellulose) Fabric Brightener: It makes the fabric looks bright because of their ability to convert ultra violet light into visible light. e.g. Fluorescent dyes. Other then theses dyes are bluing agent improves the whiteness of the fabric.
Bleachers:
These are used for laundry work in detergent but their use is limited. e.g. per oxide type bleachers these are not use under high temperature.
