Synthesis of 60 (wt.)%SiO2-40 (wt.)%CaO Sol-Gel Derived Glass-Ceramic and In Vitro Bioactivity Assessment in SBF Solution

2016 ◽  
Vol 673 ◽  
pp. 161-170 ◽  
Author(s):  
S.A. Syed Nuzul Fadzli ◽  
S. Roslinda ◽  
Firuz Zainuddin

The objective of this study is to determine the bioactive property of compacted and crystallized glass-ceramic based on 60 (wt.)%SiO2-40 (wt.)%CaO by immersion in simulated body fluid (SBF) for various times. The powder of this phosphate-free glasses based on binary SiO2-CaO system was synthesized via an acid catalyzed sol-gel route prior to powder compaction for the bioactivity assessment. The main chemical precursors used for synthesis the glass powder were tetraethylorthosilicate (TEOS) and calcium nitrate tetrahydrate reagent whereas nitric acid was used as the catalyst during the sol-gel process. The obtained hydrogels were dried, heat treated and grounded into powders before being pressed into rounded shape compacts. The initial compacted glass then sintered at 1000°C for 4 hours in typical muffle furnace to obtain crystallized glass-ceramic phase. Precipitation of apatite structures on the glass-ceramic surface were observed by immersion of the compacted pellets into SBF solution from one to 21 days. All the test results obtained from X-Ray Diffraction (XRD), Fourier Transform-Infrared (FT-IR), Field Emission-Scanning Electron Microscopy (FE-SEM) and Energy Dispersive Spectroscopy (EDS) indicates that the sintered glass-ceramic showed an actively bioactivity property. Precipitation of apatite was detected on the surface of the compacted glass-ceramic within the first 24 hours after being immersed in SBF. The development of apatite structures were continuously increased and progressively growth into coral-like structure and has particularly found to crystallize into carbonated apatite (HCA) layer after 14 days of immersion in SBF.

2019 ◽  
Vol 13 (1) ◽  
pp. 98-103 ◽  
Author(s):  
Xuan Bui ◽  
Tan Dang

A 58S bioglass with a composition in the ternary system 58SiO2-33CaO-9P2O5 (wt.%) was prepared by an innovation sol-gel process in which a small amount of ammonia was used to facilitate the condensation reactions within an acidic solution prepared by tetraethyl orthosilicate, triethyl phosphate and calcium nitrate tetrahydrate. The properties of synthetic glass were investigated by several techniques. The amorphous nature and high specific surface area (99.1m2/g) of the obtained glass were confirmed by using X-ray diffraction and low-temperature nitrogen adsorption techniques, respectively. In vitro experiments were performed by soaking glass samples in the simulated body fluid (SBF). The XRD patterns and SEM images confirmed the bioactivity of the synthesized bioglass by formation of a dense and visible hydroxyapatite layer on its surface after 2 days of in vitro assays. The ICP-OES data illustrated the ion exchange behaviours between the bioglass 58S and the SBF solution.


2019 ◽  
Vol 33 (10) ◽  
pp. 1950081 ◽  
Author(s):  
Madeeha Riaz ◽  
Rehana Zia ◽  
Snudia Aslam ◽  
Alliya Qamar ◽  
Tousif Hussain ◽  
...  

In this paper, low temperature, economical sol–gel combustion method was adopted to synthesize wollastonite ceramic. Calcium nitrate tetrahydrate and tetraethyl orthosilicate were taken as source for Ca and Si, while citric acid and nitric acid were used as chelating/combustion agents. The yielded powder calcined at 600[Formula: see text]C for 4 h was characterized by FTIR, XRD and SEM techniques. Results showed that the citrate combustion method was the most efficient method to prepare wollastonite at low temperature. Moreover, in vitro bioactivity test performed in simulated body fluid (SBF) showed good bioactivity of synthesized wollastonite ceramics.


2004 ◽  
Vol 449-452 ◽  
pp. 1121-1124 ◽  
Author(s):  
Do Won Seo ◽  
J.G. Kim ◽  
Yun Hae Kim ◽  
Chin Myung Whang

Bioactive ORMOSILS (organically modified silicate), PDMS-CaO-SiO2-P2O5 with five different P2O5 content (0, 0.01, 0.03, 0.06, 0.09 mol%) have successfully been synthesized by sol-gel process. The hybrids have been prepared with polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), calcium nitrate tetrahydrate [Ca(NO3)2 4H2O] and triethyl phosphate (TEP) as starting materials and subsequently soaked into the simulated body fluid (SBF) for different period of time and the bioactivity of hybrids was determined by examining the apatite formation on the surface of the specimen by FT-IR, Thin-Film X-ray Diffraction, and Scanning Electron Microscopy (SEM). All of the prepared samples with different P2O5 content showed in vitro bioactivity. It was observed that the increase in P2O5 content up to 0.03 mole % increases the apatite formation compared to P2O5- free hybrids. 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 phosphate ions.


2013 ◽  
Vol 11 (9) ◽  
pp. 1403-1411 ◽  
Author(s):  
Zuzana Balgová ◽  
Martin Palou ◽  
Jaromír Wasserbauer ◽  
Jana Kozánková

AbstractAbstract A series of poly(vinyl alcohol) membranes reinforced with hydroxyapatite in various weight percent — 0%, 10%, 20%, 30%, 40% and 50% were prepared. Hydroxyapatite was prepared by a sol-gel procedure using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as starting materials in an alkaline aqueous environment and then mixed with a solution of poly(vinyl alcohol), which was prepared by dissolving it in water at 85°C. The different mixtures were cast in a mould and evaporated for 7 days at a temperature of 30°C to obtain 1 mm thin membranes. FTIR spectroscopy was used to identify the different functional groups in the composites. The surface morphology was examined using a scanning electron microscope. In vitro bioactivity tests in Simulated Blood Fluid were performed for up to 28 days, especially for the membrane containing 50 wt.% HA. SEM was used to characterise the surface microstructure of biocomposite membranes before and after soaking in SBF. It was observed that the formation of clusters in membranes increases with increasing amount of HA. The clusters are formed due to agglomeration and crystal growth of HA particles during drying of the membranes. The in vitro bioactivity was found to increase with soaking time of biocomposite materials in simulated blood fluid. Graphical abstract


2013 ◽  
Vol 11 (9) ◽  
pp. 1439-1446 ◽  
Author(s):  
Lachezar Radev ◽  
Darina Zheleva ◽  
Irena Michailova

AbstractIn the present work Polyurethane (PU)/Bioglass (BG) composite materials were synthesized with different content of BG (10 and 20 mol.%) as filler. The 85S Bioglass was synthesized via polystep sol-gel method. The chemical composition of BG is 85SiO2-10CaO-5P2O5 (wt.%). The synthesis of PU was carried out by a two-step polyaddition reaction. The 85S BG was added in situ during the polymerization reaction. In vitro bioactivity of the prepared composites was examined in the presence of 1.5 SBF for 7 days in static conditions. The structure of synthesized PU/BG composites before and after in vitro test was determined by XRD, FTIR and SEM. XRD of the samples before in vitro test proved that the phase of γCa2P2O7 in the PU/20BG is visible. FTIR revealed the presence of urethane bond between OH-(from BG) and NCO groups (from PU). Based on FTIR results after in vitro test in 1.5 SBF solutions, A/B-carbonate containing hydroxyapatite (CO3HA) was formed. XRD proved that HA was formed on the surface of the samples, but Ca2P2O7 does not undergo any changes in the 1.5 SBF solution. SEM depicted the nano-HA agglomerated in spherical particles after immersion in 1.5 SBF for 7 days.


2014 ◽  
Vol 614 ◽  
pp. 7-10
Author(s):  
Hye Young Shin ◽  
Sang Hee Shin ◽  
Sang Hoon Rhee

The low crystalline hydroxyl carbonate apatite forming capacity of a poly (70lactic-co-30glycolic acid)/15CaO-85SiO2 composite, which had a dual pore structure, was newly examined in simulated body fluid. The bioactive 15CaO-85SiO2 particles were synthesized by a sol-gel method using tetraethyl orthosilicate (TEOS) and calcium nitrate tetrahydrate under acidic condition followed by the heat treatment at 600°C for 3h. The poly (70lactic-co-30glycolic acid)/15CaO-85SiO2 composite was then prepared by a solvent casting using dimethylformide as a solvent. The composite was loaded into a high pressure chamber and then carbon dioxide gas was introduced achieving a final pressure of 20 MPa. After 3 days, carbon dioxide gas was released quickly and resultantly the dual pore structure was obtained. The samples were observed by FE-SEM and its bioactivity was tested in simulated body fluid.


2007 ◽  
Vol 342-343 ◽  
pp. 817-820 ◽  
Author(s):  
Timur R. Tadjiev ◽  
Sung Su Chun ◽  
Hong Mi Kim ◽  
Inn Kyu Kang ◽  
Suk Young Kim

β-tricalcium phosphate (TCP) ceramic nanofibers via electrospinning route have been produced using β-TCP sol, which was prepared by the mixing of calcium nitrate tetrahydrate and triethyl phosphate as Ca sand P precursors, respectively. The as-prepared sol was tightly caped and aged in a drying oven at 90 °C for 16 hrs. The aged sol was evaporated in opened containers at 35 °C to reach a proper value of viscosity (100 cPs). Viscous solution was prepared by the mixing of β-TCP sol and high-molecular weight PVP to obtain appropriate viscosity for electrospinning. The mixed solution of β-TCP and PVP with various ratios were vigorously mixed using hot plate/stirrer for 24 hrs and then electrospun. The as-electrospun β-TCP nanofibers were dried in a drying oven at 60°C for 12 hrs and then heat-treated at 500, 600, 700 and 800 °C at 1°C/min heating rate in air. Surface morphology and phase identification of as-spun and heat-treated β-TCP nanofibers were studied. The results have shown that ratio between PVP and β-TCP sol and heat-treatment conditions significantly affected the crystalline phase and morphology of β-TCP nanofibers.


2007 ◽  
Vol 330-332 ◽  
pp. 207-210 ◽  
Author(s):  
Timur R. Tadjiev ◽  
Sung Su Chun ◽  
Hong Mi Kim ◽  
Inn Kyu Kang ◽  
Suk Young Kim

Bioresorbable calcium metaphosphate (CMP) nanofibers were produced by an electrospinning technique. In order to produce the nanofibers, CMP sol was prepared by the mixing of two precursors, such as calcium nitrate tetrahydrate (Ca[NO3]⋅4H2O) and triethyl phosphate (TEP, [C2H5O]3PO), using methyl alcohol as a solvent. The Ca/P ratio of the mixture was set to be 0.50 to produce stoichiometric CMP sol. At least 5 hrs of pre-hydrolysis of phosphorus precursor were required to obtain β-CMP phase. Viscous solutions for the electrospinning were made by the mixing of CMP sol and high-molecular weight polymeric solution at various ratios. The ratio of CMP sol and polymer solution was controlled to obtain an appropriate viscosity for the electrospinning. As-electrospun CMP nanofibers were dried in a drying oven at 70°C for 24 hrs and then heat-treated at various temperatures at a ramp of 1°C/min in air for 1hr. The as-electrospun and heat-treated CMP nanofibers were characterized using X-ray analysis, FT-IR, TG-DTA and SEM techniques. The results showed that the preparation of CMP sol, mixed solution properties, and heat-treatment condition of as-electrospun nanofibers significantly affect the spinability and surface morphology of the CMP nanofibers.


2010 ◽  
Vol 13 (1-2) ◽  
pp. 85 ◽  
Author(s):  
S. Manocha ◽  
Parth Joshi ◽  
Bhavini Patel ◽  
L.M. Manocha

<p>Hydroxyapatite (HAp) is a unique material having high adsorption capacity of heavy metals, high ion exchange capacity, high biological compatibility, low water solubility, high stability under reducing and oxidizing conditions, availability and low cost. Hydroxyapatite nanoparticles have been synthesized by Sol-gel method using Calcium nitrate tetrahydrate [Ca(NO<sub>3</sub>)<sub>2</sub>•4H<sub>2</sub>O] and Phosphorus pentaoxide (P<sub>2</sub>O<sub>5</sub>) as starting reactants. The addition of Phosphorus pentaoxide to Calcium nitrate tetrahydrate was carried out slowly with simultaneous stirring. After addition, solution was aged for 10 minutes for maturation. The precipitate was dried at 80 °C overnight and further heat treated at 550 °C for 2 hours. The dried and calcined particles were characterized by X-ray diffractometry, Fourier transform infra-red spectroscopy and Thermo gravimetric analysis. The particle size and morphology were studied using transmission electron microscopy. TEM examination of the treated powders displayed particles of polygon morphology with dimensions 20-50 nm in length. The FT-IR spectra for sample confirmed the formation of hydroxyapatite.</p>


2018 ◽  
Vol 280 ◽  
pp. 83-89 ◽  
Author(s):  
Siti Rohani Zainudin ◽  
S.A. Syed Nuzul Fadzli ◽  
Dewi Suriyani Che Halin ◽  
Mohd Reusmaazran Yusof ◽  
Johar Banjuraizah ◽  
...  

Bioactive glass and glass-ceramics have a huge interest in biomedical application due to their high biocompatibility and bioactive property. In this study, macro porous glass-ceramic based on 51.26% SiO2 - 36.56% CaO - 11.83% P2O5 and 42.11% SiO2 - 18.42% CaO - 29.82% Na2O - 9.65% P2O5 (in mol%) were prepared via sol-gel synthesis and powder sintering method. Sodium nitrate was used as the precursor for sodium oxide (Na2O) composition in the sol-gel glass. Effect of sodium nitrate addition on the sintered glass (glass-ceramic) properties were studied. The stabilized gel-glasses obtained were compacted into pellets and sintered at 1000 °C for 3 hours. It was found that, Na-contained glass-ceramic (Na-GC) crystallized at 71.5% due to increase in sodium-related crystalline phases. Na-GC showed 72.98% of apparent porosity and densified at 27.02% with macro porous structure with pore sizes in the range of 22.4 μm to 302 μm. The macro porous structure of Na-GC was obtained due to the foaming effect occurred during sintering. Flux effect occurred during sintering also resulted in relatively high compressive strength of Na-GC at 21.53 MPa. The macro porous Na-GC also proved to be bioactive as apatite-like structures were deposited on its surface after immersed into SBF solution for 14 days. The prepared macro porous Na-GC has high potential to be used as a scaffold material in biomedical application due to combination of suitable macro-pore size range, bioactive and has sufficient mechanical strength.


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