توليد و مشخصه يابي پودر و پوشش نانو ساختار تيتانات كلسيم به روش سل-ژل و بهبود رفتار زيست فعالي آن

چكيده انگليسي :

Fabrication and characterization of sol ـ gel Calcium titanate nanostructure powder and nanostructure coating and enhancing the bioactivity behavior Ali Maghzian a maghzian@gmail com August 5 2009 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Ahmad Monshi a monshi@cc iut ac ir AbstractRecently a new bioceramic named calcium titanate have been introduced for biomedical applications relatingorthopaedic implants Calcium titanate possesses good mechanical properties and acceptable biologicbehavior But unexpectedly the bioactivity of sol gel derived calcium titanate was not confirmed in previousstudies and has been doubted The aim of this work was to prepare and characterize nanostructure calciumtitanate powder with sol gel technique using different precursors producing calcium titanate coating withsol gel Dip coating method and investigating the effect of nano structure on the bioactivity of thisbioceramic Titanium isopropoxide and calcium nitrate were used as precursors for fabrication of powder Rapid thermal annealing RTA was used for heating dried gel in 520 1000 C to produce nano structurepowder Same precursors were used to coat calcium titanate with sol gel Dip coating followed by rapidthermal annealing on cp Ti substrates at 800 C X ray diffraction technique was used for identification ofphases and structures of products Thermal properties of dried gel were investigated by Differential scanningcalorimetry DSC Fourier transformed infrared spectroscopy was used for recognizing functional groups ofprepared powders Morphology microstructure and chemical composition of specimens were investigated byscanning electron microscopy SEM with energy dispersive X ray EDX technique In vitro evaluation ofbioactivity of prepared powder and coating was performed by soaking specimens in simulated body fluids SBF for 4 weeks Ion concentration measurements of solutions of soaked specimens were conducted byAtomic absorption spectroscopy AAS and spectrophotometry DSC thermal analysis revealed thatformation of calcium titanate crystal phase starts from 514 C and more Phase structure analysis with XRDtechnique showed the optimum temperature of rapid thermal annealing for formation of calcium titanatenanostructure powders is 800 C Mean crystallite size were estimated 56 63 nm by Scherer equation FTIRanalysis revealed the presence of important groups of hydroxyls OH and Ti OH known as new bioactivitygroup in the structure of synthesized powder SEM observations showed that powder particles are uniformspherical agglomerates with size of 500 nm XRD patterns of calcium titanate coatings confirmed thatcalcium titanate coating with perovskite structure is obtained after rapid thermal annealing for 8 min at 800 C Furthermore SEM image of coating showed uniform crack free thin coating is produced with thicknessof nearly 3 micron and crystallites smaller than 100 nm in size Results of in vitro evaluation of bioactivityvia XRD FTIR EDX and ion concentration measurements proved that calcium phosphate apatite wasformed at powder surface Also SEM micrograph of coating specimens soaked in SBF for 4 weeks showedthe presence of calcium phosphate surface precipitate and decrease in surface roughness Results of this studyproved that unlike former studies sol gel derived calcium titanate is bioactive and regarding goodmechanical properties and acceptable biocompatibility can be used for biomedical applications especiallyload bearing prosthesis

مغزيان، علي

توليد و مشخصه يابي پودر و پوشش نانو ساختار تيتانات كلسيم به روش سل-ژل و بهبود رفتار زيست فعالي آن

پوشش دهي غوطه وري , كاشتني هاي ارتوپدي , بيو سراميك ها