Physical chemical properties of surfactants in solution and their applications: A comprehensive account

In this brief review, we have discussed various physical chemical principles that guide the functions of surfactants in solution. The surfactants have special functions at the air/liquid and air/solid interfaces forming Gibbs and Langmuir monomolecular films by way of spreading at the interfaces. Their self-aggregation or micelle formation, a remarkable and useful phenomenon has been presented and elaborated. The application of fundamental physical chemistry principles for the understanding of the energetics of the micelle formation has been discussed. The involvement of surfactants in the formation of soft assembled (condensed) matters namely, vesicles, emulsions, foams, reverse micelles (or, microemulsions), gels, and so forth has been presented. The uniqueness of the “critical micelle concentration” (CMC), and its determination have been briefly presented. Applications of surfactants are numerous. We have briefly cited several applications namely, nano-material synthesis, detergency, agrochemical formulations, drug delivery, retardation of water evaporation, and so forth. A short account of bio-related surfactants namely, lung surfactants, bile salts, plant-and microbe-generated bio-surfactants, and their utilities have been also presented.