Surfactants are surface active agents, molecules that have a significant role in emulsions, suspensions, and foams. They find widespread application in personal care, cosmetics, pharmaceuticals, agrochemicals and the food industry. The main objective of this graduate level textbook is to present an overview of the classification, physical properties, phase behavior, their effects and applications of surfactants, e.g. as emulsifiers, foam stabilizer, in nano- and microemulsions and as wetting agents.

Although super-critial fluid (SCF) technology is now widely used in extraction and purification processes (in the petrochemical, food and pharmaceuticals industries), this book is the first to address the new application of cleaning. The objective is to provide a roadmap for readers who want to know whether SCF technology can meet their own processing and cleaning needs. It is particularly helpful to those striving to balance the requirements for a clean product and a clean environment. The interdisciplinary subject matter will appeal to scientists and engineers in all specialties ranging from materials and polymer sciences to chemistry and physics. It is also useful to those developing new processes for other applications, and references given at the end of each chapter provide links to the wider body of SCF literature.

The book is organized with topics progressing from the fundamental nature of the supercritical state, through process conditions and materials interactions, to economic considerations. Practical examples are included to show how the technology has been successfully applied. The first four chapters consider principles governing SCF processing, detailing issues such as solubility, design for cleanability, and the dynamics of particle removal. The next three chapters discuss surfactants and micro-emulsions, SCF interaction with polymers, and the use of supercritical carbon dioxide (CO2) as a cleaning solvent. The closing chapters focus on more practical considerations such as scale-up, equipment costs, and financial analysis.

Many contributors to this book belong to the "Joint Association for the Advancement of SCF Technology" (JAAST). A primary motivation for theformation of JAAST was the growing worldwide need to replace ozone-depleting compounds (ODCs) and smog-forming volatile organic compounds (VOCs) in manufacturing processes. Although aqueous cleaning has been adopted successfully for many applications, water is not a panacea and SCF technology has emerged as a leading alternative.

Non-ionic surfactants are chemically potent molecular species that are becoming increasingly important as an excipient component used in the formulation and delivery of drugs and vaccines. These chemicals do not have charge in their predominant working range of pH, yet interact strongly with high energy structures such as interfacial regions, phase boundaries and surfaces and can cause dramatic changes in crucial properties of molecular mixtures including solubility, dispersion uniformity, viscosity, miscibility, phase and transport. Non-ionic surfactants are used extensively in the chemical industry in such areas as detergents, health and personal care, coatings and polymers. Furthermore, non-ionic surfactants, or surface active wetting agents, reduce the surface tension of water, allowing the water molecules to spread out. When applied to water-repellent soils in high concentrations, surfactants can improve the ability of the water to penetrate the soil surface and thus increase the infiltration rate. This new book gathers the latest research from around the globe in this field.