졸겔법에 의해 다양한 P2O5의 함량으로 제조된 PDMS-Modified SiO2-CaO-P2O5의 Apatite의 형성

초록

Bioactive ORMSOLS, PDMS-CaO-SiO2-P2O5 with five diffrent P2O5 content (0, 0.01,0.03,0.06,0.09 mol%) were sucessfully sythesized by sol - gel process. The htbrids were prepared with polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] and triehyl phosphate(TEP) as starting materials and subsequently soaked into the simulated body fluid (SBF) with ionic concentration nearly equal to those in human plasma for different period of time. The bioactivity of hybrids was determinded by examining the apatite formation on the surface of the specimen by Fourier Trnasform Infrared Reflection Spectroscopy, Thin- Film X-ray Diffraction, Scanning Electron Microscopy (SEM) and X-ray Energy Dispersive Spectroscopy (EDS). All of the prepared samples with differnt P2O5 content showed in vitro bioactivity. It was observed that the increase inP2O5 content up to 0.03 mole % inceases the apatite fprmation compared to P2O5-free htbrids. The induction period for the apatite formation decresed from 9 hours for the P2O5 free hybrid to 6 hrs for 0.03 mole % P2O5 hybrid. however, further increase in P2O5 concentration slows down the formation of the apatite layer most probably due to the decrease of pH of SBF by dissolution of a large amount of phoshate ins. Results obtained by SEM - EDS showed that the sample containing 0.03 mole% P2O5 resulted in the thickest apatite layer(~6μm) after 15 days in SBF.