In-Vitro Bioactivity Characterization of Sodium-Potassium Mica and Fluorapatite Containing Glass Ceramics

2007 ◽  
Vol 330-332 ◽  
pp. 185-188
Author(s):  
Gultekin Goller ◽  
Can Cekli ◽  
Ipek Akin ◽  
Erdem Demirkesen

The aim of this study is to find out the crystallization behaviour and in-vitro bioactivity character of machinable glass ceramics having different ratios of Na/K mica and apatite phases, to ascertain the best machinable composition. In order to investigate the bioactivity behavior of the samples the simulated body fluid (SBF) was prepared. Samples were removed from the solution after 1 hour, 1 day, 1, 2, 3 and 4 weeks. FEG-SEM was used to characterize the morphology of precipitation HCA layer on the surface depending on time. Molecular bonding characterization of HCA layers were carried out by using Fourier Transform Infrared Spectroscopy (FTIR) technique. The thin film X-ray diffraction (TF-XRD) analysis was used to characterize the variation of chemical composition on precipitated layer by time. Optimum results were obtained by the composition, containing 70wt% Na/K mica and 30wt% fluorapatite which had an average mica size of 3-4 microns.

2006 ◽  
Vol 309-311 ◽  
pp. 325-328 ◽  
Author(s):  
Gültekin Göller ◽  
Ipek Akin ◽  
A. Kahraman ◽  
Erdem Demirkesen ◽  
M. Urgen

In this study; in-vitro bioactivity characterization of machinable glass-ceramics having 85 wt% sodium mica (NaMg3AlSi3O10F2) and 15 wt% fluoroapatite has been carried out. Two different heat treatment procedures are applied to the machinable glass-ceramics. The first one is nucleation at 610°C for 2 hours and crystallization at 1000°C for 3 hours and the second is nucleation at 610°C for 2 hours and crystallization at 1000°C for 4 hours. It is observed that increasing the crystallization time to 4 hours resulted in the increasing the formation of hydroxyapatite layer on surface. According to the microstructural investigations, the morphology of the precipitated crystals are different. In addition, the speed of the precipitation of hydroxyapatite is higher in glass-ceramic B than A. Thin film XRD analysis supports these results.


2006 ◽  
Vol 309-311 ◽  
pp. 321-324 ◽  
Author(s):  
Gültekin Göller ◽  
Ipek Akin ◽  
Niyazi Eruslu ◽  
E.S. Kayali

The purpose of this study is to investigate the crystallization behavior and in-vitro bioactivity character of glass ceramics having 3:7 weight ratio of flourapatite (Ca5(PO4)3F) to potassium mica (K2Mg3AlSi3O10F2) as a function of titania addition, and compare the morphology of hydroxycarbonateapatite (HCA) layer formation depending on titania addition on ceramic composition. It is observed from microstructural investigations that there is no morphology change occurred on precipitated HCA layer depending on nucleating agent in glass-ceramics. TF-XRD analysis indicates that after precipitation of initial particulates, crystallization proceeds and crystallization of precipitated HCA phase increases by increasing the time. It is observed that Ca, P ion variation in solution has two stage in terms of precipitation’ first stage represents formation of amorphous HCA and the second stage is related with crystallization. FTIR analysis strongly supports TF-XRD analysis as well.


2018 ◽  
Vol 25 (05) ◽  
pp. 1850104
Author(s):  
REHANA ZIA ◽  
MADEEHA RIAZ ◽  
AYESHA ASGHAR ◽  
TOUSIF HUSSAIN

In the present work, the effect of K2O/Na2O substitution on the bioactivity of Na2O-CaO-P2O5-SiO2 ceramics prepared by solid-state method was studied. Ceramics-based bioactive implants are economical; they require low processing temperature and are more bioactive when compared with glasses, glass ceramics and composites. K2O is known to control proper function of cells and stimulate bone formation process. The hydroxyapatite layer developed on the surface of samples after soaking in stimulated body fluid solution was studied by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. The results showed an increase in the bioactivity of the samples as Na2O was partially replaced with K2O. The addition of K2O enhanced the apatite-forming ability of the ceramic samples and makes it suitable for filling defects and fracture in bones.


MRS Advances ◽  
2017 ◽  
Vol 2 (61) ◽  
pp. 3845-3850
Author(s):  
Jorge López-Cuevas ◽  
Juan C. Rendón-Angeles ◽  
José L. Rodríguez-Galicia ◽  
Carlos A. Gutiérrez-Chavarría

AbstractGlasses and glass-ceramics of the system Diopside [D, CaMgSi2O6] - Fluorapatite [FAp, Ca5(PO4)3F] were synthesized and characterized. The studied theoretical phase compositions were (wt%): 1) 70% D-30% FAp, 2) 60% D-40% FAp and 3) 80% D-20% FAp. The glass-ceramics were synthesized by isothermal treatment of the corresponding parent glasses at either 800, 900 or 1000 °C, with holding times of either 30 min, 2 h or 5 h at high temperature. The in vitro bioactivities of all materials were tested in Kokubo’s Simulated Body Fluid (SBF), for 21 days at pH = 7.4 and 37 °C. All materials were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS). In all cases, the in vitro bioactivity increased with decreasing crystallization degree in the materials, which was likely due to an inhibitory effect of the structural changes occurring during thermal treatment of the glasses. This was more accentuated for long thermal treatments. After 21 days of soaking in the SBF, an apatite-like surface layer, with a Ca/P molar ratio close to 1.67, was formed in the case of the parent glass of composition 2. This was attributed to an enhancing effect of so-called “phase separation” phenomenon that took place during the synthesis of that particular glass. Lastly, the MgO content of the glasses made no clear difference on their in vitro bioactivity.


Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.


2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.


2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.


Author(s):  
M.T. Blatchford ◽  
A.J. Horlock ◽  
D.G. McCartney ◽  
P.H. Shipway ◽  
J.V. Wood

Abstract In this paper, the production of NiCr-TiC powder by SHS, suitable for HVOF spraying, is discussed together with results on the microstructure and coating properties. Compacts for SHS were prepared by mixing elemental Ti and C with pre-alloyed Ni-20wt.% Cr powder to give an overall composition of 35wt.% NiCr and 65wt.% TiC. These were then ignited and a self-sustaining reaction proceeded to completion. Reacted compacts were crushed, sieved, and classified to give feedstock powders in size ranges of 10-45 µm and 45-75 µm. All powder was characterized prior to spraying based on particle size distribution, x-ray diffraction (XRD), and scanning electron microscopy (SEM/EDS). Thermal spraying was performed using both H2 and C3H6 as fuel gases in a UTP/Miller Thermal HVOF system. The resulting coatings were characterized by SEM and XRD analysis, and the microstructures correlated with powder size and spray conditions. Abrasive wear was determined by a modified 'dry sand rubber wheel' (DSRW) test and wear rates were measured. It has been found that wear rates comparable to those of HVOF sprayed WC-17wt% Co coatings can be achieved.


Author(s):  
Gultekin Göller ◽  
Ipek Akin ◽  
A. Kahraman ◽  
Erdem Demirkesen ◽  
M. Urgen

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