These compounds have found many applications as addi-A colloidal dispersion of calcium thiophosphate in hydrocarbon tives in the field of lubricants. They are generally prepared medium was synthesized by reacting calcium oxide with tetraphosin the presence of a surfactant by an appropriate in situ phorus decasulfide and water in the presence of a surfactant under reaction leading to the desired structure. For example, colloispecific conditions. The resulting product can be defined as a distridal calcium carbonate is prepared by reacting carbon dioxide bution of inorganic cores surrounded by a surfactant layer in a with calcium oxide or hydroxide in the presence of a surfacreverse-micelle-type association. The chemical composition was tant, i.e., calcium alkylarylsulfonate. This one-step reaction determined by 31 P NMR, dialysis, and thermogravimetric analysis.
and micellization process occurs in well controlled solvent
The core particles were found to be a mixture of calcium thiophosand temperature conditions. Micellization mechanisms have phates, consisting mainly of mono-and dithiophosphates, with a small amount of phosphate. Shape, size distribution, and average been suggested (17).
core radius were investigated using transmission electron micros-
This paper reports the synthesis of a new colloidal inorcopy and small angle X-ray scattering. According to these techganic salt, calcium thiophosphate, in a reverse micelle assoniques, the colloidal species can be defined as polydisperse sphericiation. This colloidal calcium thiophosphate is obtained cal micelles with the radius of the mineral cores ranging from 10 from the reaction of tetraphosphorusdecasulfide and calcium to 80 A ˚. ᭧ 1997 Academic Press oxide or hydroxide with water in the presence of calcium Key Words: Colloidal calcium thiophosphate; synthesis; small alkylarylsulfonate as surfactant. The synthesis process of this angle X-ray scattering; transmission electron microscopy. compound is presented, followed by an analytical description from the chemical and physical standpoints.