Silicon Incorporation into Multiphasic Calcium Phosphate Fibers

The calcium phosphate fibers were synthesized using homogenous precipitation by addingcalcium and phosphate ions containing solutions and urea at 90° and pH 3.0 with Ca/P molarratio of 1.67 under reflux conditions for reaction time of 10 days. Two various amount ofsilicon as TEOS were added to the solution. The fibers were characterized by FTIR, XRD, SEM,and ICP spectroscopy. The results showed that the precipitated fibers were consisted biphasiccalcium phosphates, monetite and hydroxyapatite (HA). Heat treatment at 800 °C led to form atriphasic mixture of HA/β-TCP/calcium pyrophosphate with whisker-like morphology and alength and width within range of 20-100 μm and 0.2-2 μm, respectively. The measurement ofsilicon content in the fibers by ICP indicated six-fold addition of silicon as TEOS into thesolution led to two-fold increase in Si content of the fibers. The FTIR spectra of heat-treatedfibers revealed the characteristic peaks of phosphate and pyrophosphate groups with no carbonatebands. The findings indicate that the silicon seems to be incorporated into the structure ofmultiphasic fibers.

Keywords:

Silicon , Calcium phosphate fibers , Hydroxyapatite , Calcium pyrophosphate