A one-parameter model for microemulsions

Oil and water do not mix. Oil molecules like each other and so does water molecules. Oil molecules however do not like water molecules as much as their own. Thus, there exists a effective repulsive force between oil and water molecules. Imagine pouring a glass of water into a container that has oil. Eventually, the oil will phase separate and reach the top of the container. This happens as a result of the repulsive force often referred to as the hydrophobic nature of oil. Indeed gravity dictates their position, but, interaction drives the separation. As a thought experiment, imagine oil likes water. Do you think that if we repeat the same experiment in the presence of gravity, will oil come to the top of the container? I will leave this as an open question. When oil separates from water, an interface will form between the oil-rich and water-rich regions. However, there are enormous scenarios where we would like the oil to mix completely with water. It would be extremely beneficial if we can achieve this without providing mechanical work. Such stable mixtures of oil and water can be achieved by adding a surfactant. These surfactants have both oil-loving and water-loving parts and hence assemble at the interface between oil and water. Such assembly promotes thermodynamically stable mixtures (no mechanical work required) with an enormous interfacial area. Such thermodynamically stable mixtures of oil, water and surfactant are defined as microemulsions.

To understand microemulsions. This is all this thesis is about. Our target is to generate a generic yet simplistic model to the whole class of microemulsions with accuracy at the molecular level. Firstly, we will provide a brief review of microemulsions. Later, we will present various applications of microemulsions in different fields. Finally, we will discuss existing models and conclude with an outline of the thesis.