Fabrication and Properties of Hydroxyapatite-Ti Network Composites

2008 ◽  
Vol 41-42 ◽  
pp. 41-48 ◽  
Author(s):  
Zhi Meng Xiu ◽  
Yi Liu ◽  
Ji Guang Li ◽  
Di Huo ◽  
Xiao Dong Li ◽  
...  
Keyword(s):  
Bending Strength ◽  
Blood Compatibility ◽  
Sol Gel ◽  
Material System ◽  
Mechanical Mixing ◽  
Reinforcement Structure ◽  
Relative Growth Rates ◽  
3D Network ◽  
Tih2 Powder ◽  
Mixing Method

Hydroxyapatite (HA) powder was synthesized by a sol-gel method with Ca(OH)2 and H3PO4 as reactants. The HA granules were then coated with TiH2 powder using a mechanical mixing method. The HA-TiH2 material system produced HA-Ti composites after hot-pressing at 1050°C. The HA-Ti composites are mainly composed of HA and Ti, with small amounts of Ca2P2O7 and Ca3(PO4)2 phases. Fracture toughness and bending strength are 2.4 MPa·m1/2 and 54.3 MPa, respectively for the HA-20vol%Ti composite, higher than those of the pure HA ceramic. The improvement in properties is because of the unique 3D network structure of Ti, which is an ideal reinforcement structure for the weak and brittle HA. According to ISO/TR 7405-1984, hemolysis test was performed to evaluate the blood compatibility of the material. The results show that the hemolysis rate of the HA-20vol%Ti composite is 0.56%. Relative growth rates (RGR) of L-929 cells soaked after 6 days in the HA-20vol%Ti group, pure Ti group, black group and pure Pb group were 132%, 100%, 90% and 6% respectively, while the level of cytotoxicity was grade 0 in HA-Ti composite group. These results imply that the HA-20vol%Ti composite has good biocompatibility and bioactivity.

Blood Compatibility and Protein Adsorption Characteristics of Sol-Gel Derived Titania

2000 ◽  
Vol 192-195 ◽  
pp. 889-892 ◽  
Author(s):  
S. Takashima ◽  
S. Takemoto ◽  
Kanji Tsuru ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka
Keyword(s):  
Protein Adsorption ◽  
Blood Compatibility ◽  
Sol Gel ◽  
Adsorption Characteristics

scholarly journals The effect of the surface modification of carbon nanotubes on their dispersion in the epoxy matrix

2011 ◽  
Vol 13 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Maria Wladyka-Przybylak ◽  
Dorota Wesolek ◽  
Weronika Gieparda ◽  
Anna Boczkowska ◽  
Ewelina Ciecierska
Keyword(s):  
Carbon Nanotubes ◽  
Surface Modification ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Mechanical Mixing ◽  
Weight Percentage ◽  
Homogeneous Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Mixing Method ◽  
Walled Carbon Nanotubes

The effect of the surface modification of carbon nanotubes on their dispersion in the epoxy matrix Functionalization of multi-walled carbon nanotubes (MWCNTs) has an effect on the dispersion of MWCNT in the epoxy matrix. Samples based on two kinds of epoxy resin and different weight percentage of MWCNTs (functionalized and non-functionalized) were prepared. Epoxy/carbon nanotubes composites were prepared by different mixing methods (ultrasounds and a combination of ultrasounds and mechanical mixing). CNTs modified with different functional groups were investigated. Surfactants were used to lower the surface tension of the liquid, which enabled easier spreading and reducing the interfacial tension. Solvents were also used to reduce the liquid viscosity. Some of them facilitate homogeneous dispersion of nanotubes in the resin. The properties of epoxy/nanotubes composites strongly depend on a uniform distribution of carbon nanotubes in the epoxy matrix. The type of epoxy resin, solvent, surfactant and mixing method for homogeneous dispersion of CNTs in the epoxy matrix was evaluated. The effect of CNTs functionalization type on their dispersion in the epoxy resins was evaluated on the basis of viscosity and microstructure studies.

scholarly journals Microstructure and Properties of SCE-Al2O3/PES-MBAE Composite

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yufei Chen ◽  
Qiwang Dai ◽  
Xiwang Zhang ◽  
Tao Feng
Keyword(s):  
Dielectric Properties ◽  
Bisphenol A ◽  
Heat Resistance ◽  
Bending Strength ◽  
Sol Gel ◽  
Harmful Effect ◽  
Decomposition Temperature ◽  
Two Phase ◽  
Allyl Compound

SCE-Al2O3was the nano-Al2O3modified by supercritical ethanol and the surface of SCE-Al2O3was coated with active group. 4,4′-diaminodiphenylmethane bismaleimide (MBMI) was used as matrix; 3,3′-diallyl bisphenol A (BBA) and bisphenol-A diallyl ether (BBE) were used as reactive diluent, polyethersulfone (PES) as toughening agent, and SCE-Al2O3as modifier; SCE-Al2O3/PES-MBAE nanocomposite was prepared through in situ sol-gel method. The mechanism of composite toughened by PES was observed and analyzed. FTIR indicated that the reaction between MBMI and allyl compound occurred and SCE-Al2O3had doped into the polymer matrix. SEM showed that PES particle was inlaid in matrix and presented as a two-phase structure in matrix. The heat resistance, dielectric properties, and mechanical properties of SCE-Al2O3/PES-MBAE nanocomposites were evaluated. The results showed that with the incorporation of PES, although the toughness of the material improved, the heat resistance and dielectric properties of material declined, meanwhile. The adulteration of SCE-Al2O3could remedy the harmful effect caused by PES, while the content of SCE-Al2O3was reasonable. The decomposition temperature, dielectric constant, and dielectric loss of composite were 441.23°C, 3.63 (100 Hz), and 1.52 × 10−3(100 Hz); the bending strength and impact strength were 129.22 MPa and 13.19 kJ/mm2, respectively, when the content of SCE-Al2O3was 3 wt% and PES was 5 wt%.

Research on a Coated Method for Ceramic Proppant

2016 ◽  
Vol 847 ◽  
pp. 527-531 ◽  
Author(s):  
Zi Yu Zhu ◽  
Ke Lan Xiang ◽  
Ying Zi Zhao ◽  
Lin Li ◽  
Xu Wang
Keyword(s):  
Corrosion Resistance ◽  
Acid Corrosion ◽  
Cross Linking ◽  
Dispersion Method ◽  
Mechanical Mixing ◽  
Natural Gel ◽  
Acid Solubility ◽  
Mixing Method ◽  
The Common ◽  
Emulsifier Concentration

Due to the disadvantage of the traditional proppant, such as the low strength, poor acid corrosion resistance, embedding and flowback and so on, a new coated proppant was developed to deal with these problems. As the coating material, the natural gel was used to coat proppant. Different from the traditional mechanical mixing method, the means to make coated ceramic was the solvent dispersion method through the process of emulsification, cross-linking and dehydration dispersion. The strength of coated proppant was tested in different coated conditions. According to the result of test, the ceramic was coated under the optimum condition. Then the roundness, sphericity, acid solubility, crush resistance and surface structure of coated ceramic were compared with the uncoated ceramic. The experimental results showed that the optimal condition was as follows: 0.08 g/ml of gel concentration, 15/2 of ceramic/gel (g/g), 0.025 g/ml of emulsifier concentration, 20min of emulsifying time, 1/10 of water/oil rate. The coated ceramic prepared at this condition had the best performance, compared with the common ceramic, and its sphericity and acid solubility were greatly improved, bulk density reduced 7%. And the proppant surface was very smooth, the crush resistance was almost zero.

scholarly journals Influence of the synthesis route on the properties of BNBT ceramics

2009 ◽  
Vol 3 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
Elisa Mercadelli ◽  
Alessandra Sanson ◽  
Claudio Capiani ◽  
Luisa Costa ◽  
Carmen Galassi
Keyword(s):  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Microstructural Properties ◽  
Barium Acetate ◽  
Mechanical Mixing ◽  
Chemical Route ◽  
Critical Comparison ◽  
Gel Combustion

BNBT (0.94[(Bi0.5Na0.5)TiO3]-0.06BaTiO3) nanopowders were prepared starting from an aqueous solution of inorganic salts (barium acetate, bismuth nitrate, sodium nitrate and titanium isopropoxide) either by the citrate- nitrate sol-gel combustion (SGC) or by spray drying (SD). Their chemical and microstructural properties were compared with the ones of the same system obtained by mechanical mixing of oxides (SSCO). The SD and SGC powders require temperatures 150 and 300?C lower than SSCO powder to form the perovskite phase. The chemical and physical properties of the obtained powders strongly depend on the considered chemical route. Therefore the subsequent sintering step and consequently the microstructure of the obtained ceramics differ significantly. The microstructures as well the piezoelectric properties of the sintered SGC, SD, SSCO samples are investigated and a critical comparison is presented. .

scholarly journals A novel green nonaqueous sol-gel process for preparation of partially stabilized zirconia nanopowder

2017 ◽  
Vol 11 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Guo Feng ◽  
Weihui Jiang ◽  
Jianmin Liu ◽  
Quan Zhang ◽  
Qian Wu ◽  
...  
Keyword(s):  
Bending Strength ◽  
Sol Gel ◽  
Sintered Sample ◽  
Zirconium Oxychloride ◽  
Bet Surface Area ◽  
Nanometer Scale ◽  
Stabilized Zirconia ◽  
Zirconia Powder ◽  
Sol Gel Process ◽  
Sintering Behaviour

A novel green nonaqueous sol-gel process was developed to prepare 3mol% Y2O3-doped ZrO2 nanopowder from zirconium oxychloride and without need for washing of the obtained particles. It was shown that highly dispersive nanometer-scale zirconia powder with the particle size of 15-25 nm and BET surface area of 41.2m2/g can be prepared. The sintering behaviour was also investigated. Density of the translucent body sintered at 1400?C is 98.7 ? 0.3% of its theoretical density and the surface and cross section areas are dense without holes or other defects. The bending strength of the sintered sample is 928 ? 64MPa.

Preparation of BaTiO3/low melting glass core–shell nanoparticles for energy storage capacitor applications

2014 ◽  
Vol 2 (42) ◽  
pp. 18087-18096 ◽  
Author(s):  
Xiaofeng Su ◽  
Brian C. Riggs ◽  
Minoru Tomozawa ◽  
J. Keith Nelson ◽  
Douglas B. Chrisey
Keyword(s):  
Energy Storage ◽  
High Energy ◽  
Storage Capacitor ◽  
Core Shell ◽  
Material System ◽  
Shell Nanoparticles ◽  
Melting Glass ◽  
Energy Storage Capacitor ◽  
Mixing Method ◽  
Core Shell Nanoparticles

A core–shell nano-scale mixing method is applied to fabricate highly densified BaTiO3/low melting glass nanocomposites, which appear to be a promising material system for high energy storage capacitor applications.

Effects of Heat-Treatment Temperature on the Properties of Negative CTE Eucryptite Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 123-125 ◽  
Author(s):  
Yong Li ◽  
Qi Hong Wei ◽  
Ling Li ◽  
Chong Hai Wang ◽  
Xiao Li Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Heat Treatment Temperature ◽  
Bending Strength ◽  
Sol Gel ◽  
Negative Thermal Expansion ◽  
Treatment Temperature ◽  
Heat Treated

In this paper, negative thermal expansion coefficient eucryptite powders were prepared by sol-gel method using silica-sol as starting material. The raw blocks were obtained by dry pressing process after the powder was synthesized, and then the raw blocks were heat-treated at 600º, 1150º, 1280º, 1380º, 1420º and 1450°C, respectively. Variations of density, porosity and thermal expansion coefficient at different heat treatment temperatures were investigated. Phase transformation and fracture surface morphology of eucryptite heat-treated at different temperatures, respectively, were observed by XRD and SEM. The results indicate that, with the increasing heat- treatment temperature, the grain size and the bending strength increased, porosity decreased, thermal expansion coefficient decreased continuously. Negative thermal expansion coefficient of -5.3162×10-6~-7.4413×10-6 (0~800°C) was obtained. But when the heat-treatment temperature was more than 1420°C, porosity began to increase, bending strength began to decrease, which were the symbols of over-burning, while the main crystal phase didn’t change.

Mesoporous 3D network Ce-doped NiO nanoflakes as high performance electrodes for supercapacitor applications

2019 ◽  
Vol 43 (19) ◽  
pp. 7441-7456 ◽  
Author(s):  
P. E. Saranya ◽  
S. Selladurai
Keyword(s):  
High Performance ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
3D Network ◽  
Supercapacitor Applications

In the present study, pristine NiO- and Ce (0.5, 1.0, 1.5, and 2%)-doped NiO nanoflakes were synthesised using the sol–gel method for supercapacitor applications.

scholarly journals Photopatternable Epoxy-Based Thermosets

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2350 ◽  
Author(s):  
Michael Giebler ◽  
Simone Radl ◽  
Thomas Ules ◽  
Thomas Griesser ◽  
Sandra Schlögl
Keyword(s):  
Sol Gel ◽  
Surface Hardness ◽  
Polymer Chains ◽  
Cleavage Rate ◽  
Yield Increase ◽  
Ring Opening Reaction ◽  
3D Network ◽  
Simultaneous Heating ◽  
Network Properties ◽  
Spectroscopy Studies

The present work provides a comparative study on the photopatterning of epoxy-based thermosets as a function of network structure and network mobility. Local switching of solubility properties by light of a defined wavelength is achieved by exploiting versatile o-nitrobenzyl ester (o-NBE) chemistry. o-NBE derivatives with terminal epoxy groups are synthetized and thermally cured with different types of cycloaliphatic anhydrides via nucleophilic ring opening reaction. By varying the structure of the anhydride, glass transition temperature (Tg) and surface hardness are adjusted over a broad range. Once the network has been formed, the photolysis of the o-NBE groups enables a well-defined degradation of the 3D network. Fourier transform infrared (FT-IR) spectroscopy studies demonstrate that cleavage rate and cleavage yield increase with rising mobility of the network, which is either facilitated by inherent network properties (Tg below room temperature) or a simultaneous heating of the thermosets above their Tg. The formation of soluble species is evidenced by sol-gel analysis, revealing that low-Tg networks are prone to secondary photoreactions at higher exposure doses, which lead to a re-crosslinking of the cleaved polymer chains. The change in solubility properties is exploited to inscribe positive tone micropatterns within the thermosets by photolithographic techniques. Contrast curves show that the resist performance of rigid networks is superior to flexible ones, with a contrast of 1.17 and a resolution of 8 µm.

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