Baseline studies of the Clay Minerals Society source clays; colloid and surface phenomena
Baseline studies of the Clay Minerals Society source clays; colloid and surface phenomena (in Baseline studies of the Clay Minerals Society source clays, Patricia M. Costanzo (prefacer) and Stephen Guggenheim (prefacer))
Clays and Clay Minerals (October 2001) 49 (5): 446-452
The introduction emphasises the importance of understanding the thermodynamics of surfaces and interfaces as a means of acquiring knowledge about geological, technological and biological processes at the boundaries between clays and other minerals. A number of equations are given covering the free energy of interfacial action, the apolar or Lifshitz-van der Vaals interactions and polar or Lewis acid-base interactions. Discussion on the hydrophylicity/hydrophobicity of surfaces and the need for a quantitative measure of these terms is followed by discussion on the phenomena of electrostatic interactions at a water/solid interface. Results for surface tension components and associated parameters for a series of liquids are given. Contact angles of tests liquids from seven clay minerals at 20 degrees C are tabulated.