Characterization Methods of Colloids – Part I

This chapter presents the important kinetic properties of colloids, and their motion under the influence of gravitational and centrifugal fields. Kinetic properties are important for many reasons i.e. for the characterization of colloidal particles. The chapter commences with a discussion on the Brownian motion and then moves to sedimentation and creaming. It deals with the phenomenon of osmosis and the associated osmotic pressure. The problem of relating the viscosities of colloidal dispersions with the nature of the dispersed particles has been the subject of many experimental and theoretical investigations. The chapter also discusses rheology of colloids and shows that very complex behaviors can be observed depending on the shape and concentration of the colloid particles. The ultracentrifuge can be used in two distinct ways for investigating suspended colloidal material: the sedimentation velocity method and the sedimentation equilibrium method.