Preparation of lead hydroxyapatite particles using acetamide

Lead hydroxyapatite (PbHAP) particles were prepared by a homogeneous precip itation reaction of Pb(NO3)(2) and (NH4)(2)HPO4 using acetamide (AA) in aqu eous media. The particles obtained under different conditions were examined by various methods, including XRD, FTIR, SEM, ICP, TG-DTA and N-2 adsorpti on. The crystal phase of the products depended on the concentration of AA ( [AA]) and the ageing period (t(a)). Large highly crystalline needle-like Pb HAP particles were formed by ageing at [AA]=0.4-1.6 mol dm(-3) and t(a)grea ter than or equal to 1 day. At [AA]greater than or equal to 3.2 mol dm(-3) a mixture of PbHAP and alpha-Pb-3(PO4)(2) was generated. The transformation of alpha-Pb-3(PO4)(2) to PbHAP in solution at [AA]greater than or equal to 3.2 mol dm(-3) was hindered by CH3COOH, produced by hydrolysis of AA.