抄録
Zeta potential of hydroxyapatite (HAP, Ca10(PO4)6(OH)2) particle in an aqueous phase was measured in the presence of various concentrations of NaCl, sodium dodecylsulfate (SDS), and polyethylene glycol mono-p-isooctyl- phenyl ether (TX-100). It was found that the intact particle was negatively charged. Zeta potential of the particle became more negative with a concentration of SDS because of its adsorption. The potential decreased furthermore with a concentration of TX-100 at a given concentration of SDS when NaCl was not added to the system. On the other hand, the potential became less negative with a concentration of TX-100 at a constant concentration of SDS when 500 mmol/L NaCl was added. The mechanisms to explain these facts and the effect of NaCl in particular were discussed, taking into consideration the mixed micelle formation, hydration, adsorption of SDS and TX-100, and shifting of the slipping plane into an aqueous phase.
