Physical Properties of Foams and Scraping Foams

Abstract

A foam is a state in which a large number of air bubbles are packed in a small amount of liquid. As surfactants are often used to form this state, foams are often evaluated according to the type of surfactant. However, foams are one of the states and have many physical properties that are not dependent on surfactants. This article starts with the basics of bubbles, such as surface tension, liquid film stability, and the mechanism of defoaming agents, and then we explain the fundamentals of the physical properties of foams, such as osmotic pressure, and elasticity. We also introduce the scraping of foams onto a substrate as a recent research.

graphical abstract