ZETA POTENTIAL OF HYDROXYAPATITE IN THE PRESENCE OF HYDROXYPROPYLCELLULOSE AND SODIUM DODECYLSULFATE IN AN AQUEOUS PHASE (EFFECT OF FORMATION OF THE SURFACE COMPLEX)

Abstract

Adsorption of hydroxypropylcellulose(HPC) on hydroxyapatite (HAP) in the presence of sodium dodecylsulfate (SDS) and its effect on zeta potential of the HAP in an aqueous phase were studied. Although the adsorption amount of HPC was low in the absence of SDS, it increased with a concentration of SDS by virtue of formation of the complex between them on the surface. Zeta potential of the HAP was negative(-14mV) in an aqueous solution of 0.9% NaCl. Its absolute value decreased with a concentration of HPC because the slipping plane moves to the outside of the particle with the adsorption amount of HPC. The zeta potential, on the contrary, became more negative with a concentration of SDS after its adsorption and formation of the surface complex with HPC.