ABSTRACT
This chapter introduces the general concepts of surface tension, surface active agents (surfactants), surface films, and adsorption. The study of these topics utilizes principles of interfacial phenomena, physical and surface chemistry, and thermodynamics. Surfactants are important in a variety of physical processes and include materials ranging from simple soaps and detergents to complex biological molecules such as lipids and proteins. Coverage here is an introductory overview of interfacial phenomena and surfactant behavior. Surface tension and pressure are defined and discussed, as are various aspects of surfactant film behavior including surface molecular states, dynamic and equilibrium surface tension lowering, film collapse, squeeze-out, and respreading. The adsorption of surfactants is also described, and a brief introduction to surface thermodynamics and surface phase behavior is also provided. These concepts are more specifically applied to lung surfactants in subsequent chapters.
