In last weeks Physical Chemistry Laboratory class, we performed an experiment on Micelles. Micelles is the aggregation of amphiphilic molecules, called surfactants. It is an organized cluster consisting of number of monomers. Amphiphilic means that the surfactant molecule consists of molecules having a polar water-soluble group attached to a water-insoluble hydrocarbon chain. For example, soap is a surfactant. The non-polar part of soap molecules is good to attract grease on your hands and while the polar part attracts to water so the grease can be carried off of your hands. In additon, Properties of water ware changed due to the formation of micelles. For instance, the surface tension of water changes strongly as the concentration of the surfactant changes.
In our experiment, we had to measure the critical micelle concentration, which is the quantity of the surfactant containing material needed to initiate micelle formation. After the critical micelle concentration is reached, the surface tension of water would remain relatively constant. The formation of micells is also a spontaneous reaction. Therefore, it’s thermodynamicly favored.
Surfactant micelles are widely used in oil recovery in the petroleum industries. Methods for improved oil recovery process have been developed involving surfactant micelles. It was used in the aqueous system to help moving oil mixture through necessary mediums. For example, surfactants have been found to effectively lower the interfacial tension between oil and water and enable mobilization of trapped oil though the reservoir. Surfactants can also be formulated for surfactant flooding, which is a process involves forcing the oil to the surface.
Below is a video explaining how surfactant micelles are used in the petroleum industry to carry oil mixtures.