Effect of additivies on pore structure of hydroxyapatite

Hydroxyapatite (Ca10(PO4)6(OH)2, HAP) differs from other calcium phosphate salts in terms of its high biocompatibility, slow degradation, and similar chemical structure with the bone. HAP widely used in the biomedical applications due to above mentioned characteristics. In addition, the recent studies have shown that HAP is an effective adsorbent for heavy metals such as lead, zinc, copper, cobalt, cadmium, and pharmaceutical active ingredients, dyes, enzymes and proteins.In this work, effects of polymeric additives on the synthesis of porous HAP crystals were investigated. The HAP crystals were synthetized by wet precipitation method by adding industrial polymer (LS) and polyacrylic acid (PAA) at different concentrations. The HAP crystals were characterized by SEM, BET, FT-IR and X-Ray powder difraction methods. According to the SEM images, the samples are rod-shaped, and there is no apparent changes in morphology in the presence of polymer additives. Increasing the concentration of PAA increased the specific surface area of the HAP crystals while adding of industrial polymer just slightly increase.In the second part of study, the produced HAP crystals were used for Cu(II) removal from aqueous solution. The HAP crystals removed 99% of Cu(II) from aqueous solution. The adsorption kinetics were examined by Pseudo-first order and Pseudo-second order by kinetic model equations.Key words: Hydroxyapatite, wet precipitation, Cu(II), adsorption