Industrial Chemistry and Water Treatment

Surface and Colloid Chemistry

Surface and Colloid Chemistry provides a detailed analysis of its principles and applications and demonstrates how they relate to natural phenomena and industrial processes. The goal of the Division of Colloid and Surface Chemistry is to promote discovery, scholarship, and innovation in colloid, surface, interface, and nanomaterial’s chemistry as pursued by a global and multidisciplinary scientific community. The term dispersion is often used as a synonym of colloidal system. Colloid chemistry deals with matter in a state of very fine subdivision in which each particle has a high surface/volume ratio. The principles of surface chemistry therefore largely govern the special properties of colloids. The surface tension of a liquid can be defined as the work which must be performed to produce 1 sq.cm of new surface at constant temperature. Surface tension refers to the gas (usually air)/ liquid interface, the work required to produce 1 sq.cm of new surface at a liquid/liquid interface is usually termed the interfacial tension of the pair of liquids. Static surface tension - As a rule the fluid dispersions (emulsions, foams) are stabilized by adsorption layers of amphiphile molecules. These can be ionic and nonionic surfactants, lipids, proteins, etc. All of them have the property to lower the value of the surface (or interfacial) tension, s, in accordance with the Gibbs adsorption equation. If the surface of an equilibrium surfactant solution is disturbed (expanded, compressed, renewed, etc.), the system will try to restore the equilibrium by exchange of surfactant between the surface and the subsurface layer (adsorption–desorption). The change of the surfactant concentration in the subsurface layer triggers a diffusion flux in the solution.