Microstructure and Bio-Mineralization Behavior of the Sol-Gel Derived Bioactive Materials

2007 ◽  
Vol 280-283 ◽  
pp. 1609-1612 ◽  
Author(s):  
Xiao Feng Chen ◽  
Ying Jun Wang ◽  
Na Ru Zhao ◽  
Jian Dong Ye ◽  
Yu Dong Zheng ◽  
...  
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Tissue Engineering Scaffolds ◽  
Bioactive Materials ◽  
Electrode Layer ◽  
Oh Groups ◽  
Surface Areas ◽  
Gel Layer ◽  
Double Electrode ◽  
Sbf Solution

The biomaterials in system CaO-P2O5-SiO2 were synthesized via sol-gel method. The biomaterials can be applied to bone reparation and bone tissue engineering scaffolds The nano-pore structure, degradability, bioactivity and bio-mineralization characteristic of the biomaterials were investigated in details using XRD, SEM/EDX, FTIR, BET and DSC/TG techniques. It was indicated that the sol-gel derived biomaterials have a higher bioactivity than that of the melt derived bioactive glasses or glass-ceramics. It just takes 4-8 hours for HCA to form on the surface of the sol-gel samples in SBF solution at 37°C. The spherical HCA crystal clusters formed on the surface of the sol-gel derived samples immersed in SBF for 8 hours have a low crystallinity. Owing to their interconnected nano-sized pores, the sol-gel samples possess much higher surface areas and the hydrous porous SiO2 gel layer containing a great amount of ºSi-OH groups can be rapidly formed on the biomterials’ surface through a quick ion exchange between H3O+ in the solution and Ca2+ in the surface of the materials. ºSi-OH groups can play a very important role in inducing formation of HCA. They make the material surfaces electronegative, which resulted in a double electrode layer formed between the samples surface and SBF solution. The double electrode layer is in favor of formation of HCA on the surface of the materials.

Preparation and Characterization of Macro Porous Glass-Ceramics as Bioactive Scaffold Material

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 ◽  
...  
Keyword(s):  
Porous Structure ◽  
Sodium Nitrate ◽  
Porous Glass ◽  
Glass Ceramic ◽  
Biomedical Application ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Scaffold Material ◽  
Powder Sintering ◽  
Sbf Solution

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.

CHARACTERIZATION OF TITANIUM PHOSPHATE AS ELECTROLYTES IN FUEL CELLS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4147-4152 ◽  
Author(s):  
A. T. T. TRAN ◽  
M. C. DUKE ◽  
P. G. GRAY ◽  
J. C. DINIZ DA COSTA
Keyword(s):  
Fuel Cells ◽  
Relative Humidity ◽  
Proton Conductivity ◽  
Proton Exchange Membrane ◽  
Sol Gel ◽  
Proton Exchange ◽  
Titanium Phosphate ◽  
Molar Ratio ◽  
Oh Groups ◽  
Surface Areas

Titanium phosphate is currently a promising material for proton exchange membrane fuel cells applications (PEMFC) allowing for operation at high temperature conditions. In this work, titanium phosphate was synthesized from tetra iso-propoxide (TTIP) and orthophosphoric acid ( H 3 PO 4) in different ratios by a sol gel method. High BET surface areas of 271 m2.g-1 were obtained for equimolar Ti:P samples whilst reduced surface areas were observed by varying the molar ratio either way. Highest proton conductivity of 5.4×10-2 S . cm -1 was measured at 20°C and 93% relative humidity (RH). However, no correlation was observed between surface area and proton conductivity. High proton conductivity was directly attributed to hydrogen bonding in P - OH groups and the water molecules retained in the sample structure. The proton conductivity increased with relative humidity, indicating that the Grotthuss mechanism governed proton transport. Further, sample Ti/P with 1:9 molar ratio showed proton conductivity in the order of 10-1 S.cm-1 (5% RH) and ~1.6×10-2 S . cm -1 (anhydrous condition) at 200°C. These proton conductivities were mainly attributed to excess acid locked into the functionalized TiP structure, thus forming ionisable protons.

Bioactive Glass-Ceramic Porous Sinters

2006 ◽  
Vol 49 ◽  
pp. 103-108
Author(s):  
R. Sindut ◽  
Katarzyna Cholewa-Kowalska ◽  
Maria Łączka
Keyword(s):  
Bioactive Glass ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Diffraction Method ◽  
Thin Layers ◽  
Molar Ratio ◽  
Chemical Compositions ◽  
Bioactive Materials

Bioglasses and bioactive glass-ceramics have found increasingly wide application in medicine and dentistry. Using sol-gel method, is possible to obtain glass and glass-ceramic bioactive materials of new generation, characterized the higher bioactivity than melted bioglasses. These materials can be produced in various final forms, as powders, thin layers on different base and porous sinters. Production of porous bioactive sinters from gel-derived powders is a new problem and the parameters controlling this process are not recognized yet. The aim of the study was to obtain porous bioactive sinters from gel-derived powders of the SiO2-CaO-P2O5 system of four various chemical compositions (S2, II, I, A2) and the characterization of properties of these new materials. The starting powders differ from each other in the content of the basic components, at the molar ratio of CaO to SiO2 equals 0.2-1.35. To obtain the porous sinters a method of burning additions and deposition of the casting slip on the polymeric sponge was used. Sintering was realized in several stages, at the maximal temperature 1200oC. By selecting appropriate conditions of sintering, a durable material of high open porosity up to 77 % was obtained. Its porous structure was characterized by a prevailing number of small micropores of similar dimensions, uniformly distributed in the material. The phase composition of obtained sinters was determined by the X-ray diffraction method. All sinters represented glass-ceramic materials with apatite, cristoballite and calcium silicates as a main crystalline phases. In order to preliminary determination bioactivity of obtained sinters, test in vitro in simulated body fluid SBF was conducted. It was found that hydroxyapatite formation on the sinter surface occurs only in the case of biomaterials of highest calcium concentration.

scholarly journals Influence of thermal treatment on the structure and in vitro bioactivity of sol-gel prepared CaO-SiO2-P2O5 glass-ceramics

2014 ◽  
Vol 8 (3) ◽  
pp. 155-166 ◽  
Author(s):  
Lachezar Radev
Keyword(s):  
Thermal Treatment ◽  
Calcium Silicate ◽  
Sol Gel ◽  
Glass Ceramics ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
X Ray ◽  
Vitro Test ◽  
Sbf Solution

Nowadays there is a substantial practical interest in the in vitro bioactivity of calcium silicate phosphate (CSP) glass-ceramics and carbonate apatite (CO3HA) formation on their surfaces after in vitro test in simulated body fluid (SBF). The main purpose of the presented article is the evaluation of the chemical composition of the gel with nominal composition 70.59 CaO:28.23 SiO2:1.18 P2O5 (mol.%) on the structure, crystallization behaviour and in vitro bioactivity in SBF solution for 14 and 28 days. The prepared glass-ceramics have been synthesized via a polystep sol-gel method. The structure of the obtaining samples was studied by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). After thermal treatment of the samples XRD confirmed the presence of ?-Ca2SiO4 and Ca15(PO4)2(SiO4)6, and indicated that at 1500?C Ca15(PO4)2(SiO4)6 becomes predominant phase. FTIR revealed the presence of all characteristics bands for calcium silicate phosphate (CSP) bonds. SEM monitors the presence of particles with different morphology. After in vitro test in SBF, FTIR depicted that B-type carbonate containing hydroxyapatite (CO3HA) is preferentially formed on the immersed glass-ceramics. SEMof the precipitated layers showed the presence of HA spheres. The changes in SBF solution after soaking the samples were recorded by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

scholarly journals A Molecularly Imprinted Sol-Gel Electrochemical Sensor for Naloxone Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 631
Author(s):  
Narges Shaabani ◽  
Nora W. C. Chan ◽  
Abebaw B. Jemere
Keyword(s):  
Indium Tin Oxide ◽  
Sol Gel ◽  
Electrochemical Techniques ◽  
Electrochemical Determination ◽  
Multiwall Carbon Nanotube ◽  
Molecularly Imprinted ◽  
Gel Layer ◽  
Sensing Material ◽  
Relative Standard ◽  
Optimized Conditions

A molecularly imprinted sol-gel is reported for selective and sensitive electrochemical determination of the drug naloxone (NLX). The sensor was developed by combining molecular imprinting and sol-gel techniques and electrochemically grafting the sol solution onto a functionalized multiwall carbon nanotube modified indium-tin oxide (ITO) electrode. The sol-gel layer was obtained from acid catalyzed hydrolysis and condensation of a solution composed of triethoxyphenylsilane (TEPS) and tetraethoxysilane (TES). The fabrication, structure and properties of the sensing material were characterized via scanning electron microscopy, spectroscopy and electrochemical techniques. Parameters affecting the sensor’s performance were evaluated and optimized. A sensor fabricated under the optimized conditions responded linearly between 0.0 µM and 12 µM NLX, with a detection limit of 0.02 µM. The sensor also showed good run-to-run repeatability and batch-to-batch performance reproducibility with relative standard deviations (RSD) of 2.5–7.8% (n = 3) and 9.2% (n = 4), respectively. The developed sensor displayed excellent selectivity towards NLX compared to structurally similar compounds (codeine, fentanyl, naltrexone and noroxymorphone), and was successfully used to measure NLX in synthetic urine samples yielding recoveries greater than 88%.

ChemInform Abstract: Preparation and Characterization of Machinable Mica Glass-Ceramics by the Sol-Gel Process.

ChemInform ◽  
1989 ◽  
Vol 20 (9) ◽  
Author(s):  
T. HAMASAKI ◽  
K. EGUCHI ◽  
Y. KOYANAGI ◽  
A. MATSUMOTO ◽  
T. UTSUNOMIYA ◽  
...  
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Sol Gel Process

Effect of coating composition on the anticorrosion performance of a silane sol–gel layer on mild steel

RSC Advances ◽  
2015 ◽  
Vol 5 (129) ◽  
pp. 106485-106491 ◽  
Author(s):  
A. Foroozan E. ◽  
R. Naderi
Keyword(s):  
Mild Steel ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Sol Gel ◽  
Gel Layer ◽  
Gel Film ◽  
Coating Composition ◽  
Anticorrosion Performance ◽  
Protective Performance ◽  
Mild Steel Substrate

In this study, the effect of coating composition on the protective performance of an eco-friendly silane sol–gel film applied on a mild steel substrate was investigated using electrochemical impedance spectroscopy and surface analysis methods.

Porous Phosphor Thin Films of Oxyfluoride SiO2–BaMgF4: Eu2+Glass–Ceramics Prepared by Sol–Gel Method

2003 ◽  
Vol 32 (10) ◽  
pp. 928-929 ◽  
Author(s):  
Shinobu Fujihara ◽  
Seiki Kitta ◽  
Toshio Kimura
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Gel Method ◽  
Sol Gel Method

Structure and up-conversion luminescence in sol–gel derived Er3+–Yb3+ co-doped SiO2:PbF2 nano-glass–ceramics

2009 ◽  
Vol 32 (1) ◽  
pp. 104-107 ◽  
Author(s):  
J. del-Castillo ◽  
A.C. Yanes ◽  
J. Méndez-Ramos ◽  
V.K. Tikhomirov ◽  
V.D. Rodríguez
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Co Doped

Novel Glass-Ceramics for Dental Application by Sol Gel Technique

2008 ◽  
Vol 396-398 ◽  
pp. 153-156 ◽  
Author(s):  
Xanthippi Chatzistavrou ◽  
E. Hatzistavrou ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
Eleana Kontonasaki ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Preparation Method ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Dental Restorations ◽  
Gel Technique ◽  
Gel Preparation ◽  
Dental Applications ◽  
Potential Use

The aim of this study was the fabrication using a sol-gel technique of a new glass-ceramic with potential use in dental applications. The characterization of the composition and microstructural properties of the produced material confirmed the similarity between the new sol-gel derived glass-ceramic and a commercial leucite based fluorapatite dental glass-ceramic. The produced material has potential application in dental restorations and it is expected to exhibit better control of composition, microstructure and properties due to the intrinsic advantages of the sol-gel preparation method.

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