scholarly journals Bioactive glass 58S prepared using an innovation sol-gel process

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.

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.


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 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.


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


2009 ◽  
Vol 618-619 ◽  
pp. 325-328 ◽  
Author(s):  
Jian Yu Xiong ◽  
Yun Cang Li ◽  
Peter D. Hodgson ◽  
Cui E Wen

Hydroxyapatite (HA) was coated on the surface of a titanium-niobium (Ti-Nb) alloy by a sol-gel process. Triethyl phosphite and calcium nitrate were used as the phosphorus (P) and calcium (Ca) precursors respectively to prepare a Ca/P sol solution. The Ti-Nb alloy was dip-coated in the sol and heated at 600°C for 30 minutes. X-ray diffraction (XRD) analysis indicated the major phase constituent of the coating after heat treatment was HA. Scanning electron microscopy (SEM) observation showed that a few cracks were distributed on the HA coating. The in-vitro bioactivity of the HA coated Ti-Nb alloy was assessed using a cell culture of SaOS-2 osteoblast-like cells. The density of cell attachment was determined by MTT assay; the cell morphology was observed by SEM. Results indicated that the density of cell attachment on the surface of the Ti-Nb alloy was significantly increased by HA coating. Cell morphology observation showed that cells attached, spread and grew well on the HA coated surface. It can be concluded that the HA coating improved the in-vitro bioactivity of Ti-Nb alloy effectively.


2017 ◽  
Vol 11 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Vương Bùi

Bioactive ceramic powder containing 45% SiO2, 24.5% CaO, 24.5% Na2O and 6% P2O5 (wt.%) was synthesized using a new sol-gel process. The preparedmaterial was investigated by several physico-chemical methods. The X-ray diffraction showed the presence of two crystalline phases, Na6Ca3Si6O18 and NaCaPO4. The high specific surface area (47m2/g) and a mesoporous structure with the average pore size of 2.6 nm were confirmed using low-temperature nitrogen adsorption technique. In vitro experiments were carried out by soaking the powder sample in simulated body fluid (SBF) at different times. XRD, FTIR and SEM coupled with EDS were used for in vitro evaluation of bioactivity. The obtained results confirmed that the ceramic powder can be used as biomaterial for bone tissue engineering due to its high bioactivity expressed by the rapid formation of a biological carbonated hydroxyapatite layer on its surface after in vitro assay.


2017 ◽  
Vol 4 (12) ◽  
pp. 171098 ◽  
Author(s):  
Muhammad Anwaar Nazeer ◽  
Emel Yilgor ◽  
Mustafa Baris Yagci ◽  
Ugur Unal ◽  
Iskender Yilgor

Synthesis of hydroxyapatite (HA) through sol–gel process in different solvent systems is reported. Calcium nitrate tetrahydrate (CNTH) and diammonium hydrogen phosphate (DAHP) were used as calcium and phosphorus precursors, respectively. Three different synthesis reactions were carried out by changing the solvent media, while keeping all other process parameters constant. A measure of 0.5 M aqueous DAHP solution was used in all reactions while CNTH was dissolved in distilled water, tetrahydrofuran (THF) and N , N -dimethylformamide (DMF) at a concentration of 0.5 M. Ammonia solution (28–30%) was used to maintain the pH of the reaction mixtures in the 10–12 range. All reactions were carried out at 40 ± 2°C for 4 h. Upon completion of the reactions, products were filtered, washed and calcined at 500°C for 2 h. It was clearly demonstrated through various techniques that the dielectric constant and polarity of the solvent mixture strongly influence the chemical structure and morphological properties of calcium phosphate synthesized. Water-based reaction medium, with highest dielectric constant, mainly produced β-calcium pyrophosphate (β-CPF) with a minor amount of HA. DMF/water system yielded HA as the major phase with a very minor amount of β-CPF. THF/water solvent system with the lowest dielectric constant resulted in the formation of pure HA.


2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.


2016 ◽  
Vol 697 ◽  
pp. 293-296
Author(s):  
Xiao Yang Zhang ◽  
Xi Wei Qi ◽  
Zhi Yuan Yang ◽  
Li Bao ◽  
Min Zhang

Hydrothermal method and sol-gel process were used to synthesize multiferroic BiFeO3 ceramics. X-ray diffraction, scanning electron microscopy, vickers diamond indenter and three-point bending method were used to investigate the effects of methods on the phase structure, microstructures and mechanical properties. Cold isostatic pressing on the ceramics with two different loads (10 MPa, 200 MPa) was used to illustrate the influence of pressure in mechanical properties. The results show that all samples are crystallized in the perovskite phase. A few small traces of impurity are observed at a 2θ of ~28 o, which are found to be those of Bi2Fe4O9. The SEM images depict that samples prepared by sol-gel process are more uniform and the grain size is slightly larger than that of hydrothermal processed samples. The investigations on the hardness and flexural strength demonstrate the ceramics prepared by hydrothermal method have better mechanical properties than that of sol-gel process, and the mechanical properties can be obviously enhanced by increasing pressure.


Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3281
Author(s):  
Yeongjun Seo ◽  
Tomoyo Goto ◽  
Sunghun Cho ◽  
Tohru Sekino

Bioactive glasses are promising materials for various applications, such as bone grafts and implants. The development of sintering techniques for bioactive glasses is one of the most important ways to expand the application to biomaterials. In this paper, we demonstrate the low-temperature mineralization sintering process (LMSP) of glass nanoparticles and their crystallization behavior. LMSP is a novel process employed to densify glass nanoparticles at an extremely low temperature of 120 °C. For this new approach, the hydrothermal condition, mineralization, and the nanosize effect are integrated into LMSP. To induce mineralization in LMSP, bioactive glass nanoparticles (BGNPs, 55SiO2-40CaO-5P2O5, mol%), prepared by the sol-gel process, were mixed with a small amount of simulated body fluid (SBF) solution. As a result, 93% dense BGNPs were realized under a temperature of 120 °C and a uniaxial pressure of 300 MPa. Due to the effect of mineralization, crystalline hydroxyapatite (HAp) was clearly formed at the boundaries of BGNPs, filling particles and interstitials. As a result, the relative density was remarkably close to that of the BGNPs conventionally sintered at 1050 °C. Additionally, the Vickers hardness value of LMSP samples varied from 2.10 ± 0.12 GPa to 4.28 ± 0.11 GPa, and was higher than that of the BGNPs conventionally sintered at 850 °C (2.02 ± 0.11 GPa). These results suggest that, in addition to LMSP being an efficient densification method for obtaining bulk bioactive glasses at a significantly lower temperature level, this process has great potential for tissue engineering applications, such as scaffolds and implants.


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