title: Decrease in the solubility product of hydroxyapatite by the adsorption of surface-active ion.
abstract: The solubility product (Ksp) of hydroxyapatite (HAP) in ionic surfactant solutions decreased with an increase in the adsorbed amount of the surface-active ions (dodecylammonium and dodecyl sulfate ions). In the presence of nonionic surfactant (polyoxyethylene(10) octylphenyl ether), Ksp was almost constant within the limit of experimental error. It was concluded that the decrease in Ksp is due to the decrease in the chemical potential of HAP through the adsorption of the surface-active ion on HAP, and due to the spontaneous change in the constituent ions of the HAP surface (i.e., surface complex formation) by ion-exchange with the surface-active ion.
authors.forename: S
authors.initials: S
authors.lastname: Shimabayashi
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Nakagaki
mesh_terms: D000327:Adsorption; D006882:Hydroxyapatites / Q000032:analysis*; D007700:Kinetics; D012995:Solubility; D013501:Surface-Active Agents
chemical_list: D006882:Hydroxyapatites; D013501:Surface-Active Agents