Why does micelle formation takes place when soap is added to water? Will a micelle be formed in other solvents like ethanol also?
answer in french language
Answers
La formation de micelles a lieu lorsque du savon est ajouté à de l'eau car les chaînes hydrocarbonées des molécules de savon sont hydrophobes (craignant l'eau), insolubles dans l'eau, mais les extrémités ioniques des molécules de savon sont hydrophiles (ils aiment l'eau) et sont donc solubles dans l'eau. La formation de micelles n'aura pas lieu lorsque du savon est ajouté à des solvants organiques tels que l'éthanol, car les chaînes hydrocarbonées des molécules de savon sont solubles dans les solvants organiques tels que l'éthanol.
A soap is a sodium or potassium salt of long chain fatty acids. It has one polar end and one non-polar end. The polar end is hydrophilic in nature (this end is attracted towards water). The non-polar end is hydrophobic (it is attracted towards hydrocarbons). When soap is added to water, soap molecules arrange themselves in a cluster to keep the non-polar portion out of water such that the non-polar ends are in the interior of the cluster and the polar ends are on the surface of the cluster. Since the dirt present on clothes is organic in nature and insoluble in water, the hydrophobic ends of the clusters attach themselves to the dirt. This cluster formation in which the dirt is entrapped is the micelle.
Micelle formation does not occur in alcohol because the alkyl chain of soap becomes soluble in alcohol.