Abstract
Formation of an intermolecular complex between sodium dodecylsulfate(SDS) and polyvinylpyrrolidone(PVP) on the surface of hydroxyapatite(HAP) and its effect on dispersion/flocculation of the HAP particles were studied in an aqueous phase. PVP alone was scarcely adsorbed on HAP. However, it was adsorbed in the presence of SDS bound on the surface of HAP, forming the surface complex between PVP and SDS by virtue of hydrophobic interaction.
In the absence of SDS, PVP did not affect the mean diameter(d) of secondary particles of HAP irrespective of its concentrations. The d-value, however, decreased after attaining a maximum with a concentration of PVP when a certain amount of SDS was added. These facts mean that the SDS-PVP complex behaves as dispersing and flocculating agents for the HAP particles. The d-values were measured as a function of concentrations of SDS and PVP.
