FACTORS IN DETERGENT ACTION .pptx, a ppt of Detergents
- 1. 1 FACTORS IN DETERGENT ACTION ASWIN.G 20204012504109 II MSC CHEMISTRY
- 2. 2 DETERGENT: Amphipathic molecules that contain charged hydrophilic or polar groups at the end of long lipophilic hydrocarbon groups are called detergents. The charged hydrophilic group is called head. The long lipophilic hydrocarbon group is called the tail. Detergents are also known as surfactants as they have ability to decrease the surface tension of water. The concentration at which micelles formation starts is called as critical micelle concentration(CMC).
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- 4. 4 CHARACTERISTICS OF DETERGENTS: • Detergents are sodium salts of long chain alkyl sulphates or a long chain of alkyl benzene sulponates. • They can be used in hard water and acidic medium. • They are non-Biodegradable.Hence they cause water pollution. e.g. Sodium n-dodecyl benzene sulphonate,cetyltrimethylammonium bromide,pentaerithrityl stearate. • The temperature at which the detergent solution is around or above its critical micelle concentration(CMC) separates into two phases is called the cloud point.
- 5. 5 FACTORS IN DETERGENT ACTION o The fact that successful detergent seems to show the collidal properties discussed has leds to the thought that micelles must be directly involved in detergent action. e.g.Solubilization was one factor in detergent action.Since micelles are able to solubilize dyes and other organic molecules.
- 6. 6 Solubilization is the process of incorporating the solubilizate (the component that undergoes solublization) into or onto micelles. Solublization may occur in a system consisting of a solvent, an association colloid (a colloid that forms micelles), and at least one other solubilizate. Schematic representation of micellar solubilization of fatty substance in water with the use of a dispersant
- 7. 7 o Much of ordinary soil involves particulate,more or less geasy matter and an important attribute of detergent is their ability to keep such material suspended in solution once it detached from the fabric and thus to prevent its redeposition. o This type of action not present,washing would involve aredistribution rather than removal of dirt. o Detergents thus do possess suspending power.For e.g.carbon suspension. o Dirt is mostly oily in nature and hence it does not dissolve in water. Sodium or potassium salts of long chain carboxylic acids make up the molecule of soap so that the carbon chain dissolves in oil and the ionic end dissolves in water.
- 8. 8 o A related effect and one that is also important to good detergency is called productive action. o This refers to the prevention of the particles of solid from adhering to the fabric. o Another component of detergent formulations is known as a builder a substance with no detergent properties of its own but one that enhances the performance of detergent. o A typical builder would be pyrophospate(Na₄P₂O₇);its effect may be
- 9. 9 o Recent concerns about excessive phosphate discharge into natural waters have led to a search for alternative builders. o There has been some success with mixture of electrolytes and sequestering agents. o The general picture of detergent action that has emerged is that of a balance of opposing forces. o The soil tends to remain on the fabric through surface tensional adhesion and on the other hand ,tends to remain in suspension as a result of the suspending power and protective action of the detergent.
- 10. 10 REFERENCES : ARTHUR W.ADAMSON,ALICE P.GAST – PHYSICAL CHEMISTRY OF SURFACES - WILEY
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