Compositional Dependence of Apatite Formation in Sol-Gel Derived Organic - Inorganic Hybrids

초록

In the present study, we report bioactivity of PDMS-CaO-SiO2-P2O5 hybrid materials prepared by sol-gel method. The apatite formation on the surface of specimen, after soaking in the simulated body fluid (SBF), were analyzed by thin-film X-ray diffraction (TF-XRD) method and Fourier Transform Infrared (FT-IR) reflection spectroscopy. The structure and morphology of the surface layer were observed by FT-Raman spectroscopy, BET and Scanning Electron Microscopy (SEM). It was found that the bioactivity increased with decreasing PDMS content and increasing CaO content. Also, the increase in P2O5 concentration from 0 to 3 mole % decreased induction period for apatite formation. Further increase in P2O5 content, however, increased induction period. It was also noted that the increase in the P2O5 concentration from 0 to 3 mole % increased the surface area, micropore area/volume, and decreased the pore diameter. On the other hand, the opposite trends were observed with further increase in the P2O5 concentration. Among the various ormosil samples prepared with different compositions, the highest bioactivity was obtained from the ormosil with the composition of 20wt% PDMS [PDMS/(TEOS+ PDMS)], 15mole % CaO[(Ca(NO3)2 / TEOS) mole ratio], 3mole % P2O5[TEP/TEOS mole ratio].