ساخت و مشخصه يابي بيوسراميك نانوكريستالي فورستريت به روش فعال سازي مكانيكي

چكيده انگليسي :

139 Synthesis and characterization of forsterite nanocrystalline bioceramic by mechanical activation Fariborz Tavangarian f tavangarian@yahoo com March 01 2010 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor R Emadi remadi@cc iut ac ir Abstract In recent years some Si and Mg containing ceramics have drawn interests in the development of bone implant materials Forsterite Mg2SiO4 is such materials which introduce recently as a bioceramic Furthermore forsterite nanopowder has shown better bio behavior in comparison with micronize forsterite The objective of present research was to provide and characterize of forsterite nanocrystalline powder by mechanical activation and to evaluate the bio quality In this study talc magnesium carbonate magnesium oxide ammonium fluoride and ammonium chloride powders were used as initials materials Ammonium fluoride and ammonium chloride powders were utilize as the speedup reagent of the process The influence of different factors such as mechanical activation time heat treatment temperature and time using calcined initial materials ammonium fluoride and ammonium chloride powders on the phase structure and crystallite size of prepared powders was investigated Various techniques were employed to evaluate and characterize the produced product To evaluate the phase structure and support of appearance of desirable phases in obtained composition X ray diffraction XRD technique was used Thermal gravimetry analysis TGA was used to evaluate the thermal behavior of produced product To investigate the morphology and particle size distribution of starting and obtained powders Scanning electron microscopy SEM was employed Also morphology and crystallite size nanocrystalline forsterite powders were characterized by Transition electron microscopy TEM The particle size distribution of forsterite powder was measured by dynamic light scattering DLS To study degradability nanocrystalline forsterite powder was pressed to tablets and situated in Ringer s solution for 4 weeks Furthermore the bioactivity of produced nanocrystalline forsterite powder after making tablets was evaluated by putting them in simulated body fluid SBF for 4 weeks Fourier transform infra red FTIR was employed to characterized the available functional group on the surface of soaked samples in SBF Morphology and appearance of formed apatite on the surface of various samples was evaluated by SEM Energy dispersive x ray EDX was used to investigate the formed apatites In addition Atomic adsorption spectroscopy AAS was utilized to study the release of ions and approval to the apatite formation Considering performed experiments and thermodynamic evaluation of the system some mechanisms was proposed to explain reactions which were done in the procedure of producing nanocrystalline forsterite powder as a hypothesis Results showed that in the absence of fluorine and chlorine ions single phase nanocrystalline forsterite powder could be obtained after 5 mechanical activation time of talc and magnesium oxide and subsequent annealing at 1000 C for 1 h with crystalline size of about 40 nm Also nanocrystalline forsterite powder could be provided by 10 h mechanical activation of talc and magnesium carbonate after post annealing at 1000 C for 10 min with crystallite size of 30 nm Presence of fluorine and chlorine ions caused reduction in mechanical activation time and thermal treatment In contrast the crystallite size was increased as a result of changing the forsterite for mechanism nanocrystalline forsterite powder was obtained after 5 h mechanical activation of talc and magnesium carbonate and adding ammonium fluoride and mixing them for extra 5 min with ball milling and 1 h heat treatment at 1000 C with crystalline size of 53 nm Furthermore nanocrystalline forsterite powder could be obtained after 5 h mechanical activation of talc and magnesium carbonate and adding ammonium

توانگريان، فريبرز

ساخت و مشخصه يابي بيوسراميك نانوكريستالي فورستريت به روش فعال سازي مكانيكي

مواد نانو ساختار , زيست اضمحلال , زيست فعال