Geometric Properties: Size and Shape

Abstract

Geometric properties are those that can be derived from the geometry of a solid body or particle. They are very important as a means by which the size and shape of an irregular shaped particle can be easily quantified. This is true whether the particle is treated as an individual solid body, or as one that is representative of many particles in a disperse system. Material systems that consist of particles surrounded by a continuous medium are known as disperse systems. The particles form the disperse phase, and the surrounding medium is the continuous phase. The size of the particles can vary from the magnitude of 10−1 m (grapefruit, melons, potatoes) to 10−6 m (emulsions), and down to 10−8 m (colloids and nanoparticles). Particles can be solid, liquid or gaseous. Six different classes of disperse systems are known (Table 3.1).