ABSTRACT
The subject of this chapter represents one of the most diverse areas in soft matter science. Colloidal materials are systems in which small droplets or particles of one material are dispersed in a continuous phase of another material. This definition is deliberately broad as colloidal systems span an extremely wide range of materials, from solid particles suspended in aqueous solution, to droplets of moisture in the air, and foams, and can even be extended to include granular materials like sand. Colloidal science is a subject that is particularly relevant in our everyday lives because it plays an important role in the manufacture of numerous everyday substances. Many of the foods we eat can be described as colloids. Creamy foods, like mayonnaise, sauces, or ice cream, contain tiny droplets of fat dispersed in an aqueous medium; food can be foams (liked whipped cream), and it can be a solid sponge (like bread or cake). Personal care products like face creams and toothpastes are colloidal systems, as are household paints and inks. Even the dilute polymer solutions discussed in Chapter 4 can be considered colloids.
