Nanosized Hydroxyapatite Powder Synthesized from Eggshell and Phosphoric Acid

2007 ◽  
Vol 7 (11) ◽  
pp. 4061-4064 ◽  
Author(s):  
Sang-Jin Lee ◽  
Young-Soo Yoon ◽  
Myung-Hyun Lee ◽  
Nam-Sik Oh
Keyword(s):  
Phosphoric Acid ◽  
Heating Temperature ◽  
Average Particle Size ◽  
Stoichiometric Composition ◽  
Synthesis Process ◽  
Average Particle ◽  
Mixing Ratio ◽  
Powder Synthesis ◽  
Chemical Route ◽  
Milling Method

The present research describes synthesis of highly sinterable, nano-sized hydroxyapatite (HAp) powders using a wet chemical route with recycled eggshell and phosphoric acid as calcium and phosphorous sources. The raw eggshell was easily turned to CaO by the calcining process, and phosphoric acid was mixed with the calcined eggshell by the wet, ball-milling method. The crystalline development and microstructures of the synthesized powders and sintered samples were examined by X-ray diffractometry and scanning electron microscopy, respectively. The observed phases on the powder synthesis process were dependent on the mixing ratio (wt%) of the calcined eggshell to phosphoric acid and the heating temperature. The ball-milled, nano-sized HAp powder, which has an average particle size of 70 nm, was fully densified at 1300 °C for 1h. The Ca/P ratio for stoichiometric composition of HAp was controlled by adjustment of the mixing ratio.

scholarly journals Green synthesis: Proposed mechanism and factors influencing the synthesis of platinum nanoparticles

2020 ◽  
Vol 9 (1) ◽  
pp. 386-398 ◽  
Author(s):  
Mahmood S. Jameel ◽  
Azlan Abdul Aziz ◽  
Mohammed Ali Dheyab
Keyword(s):  
Green Synthesis ◽  
Reaction Temperature ◽  
Platinum Nanoparticles ◽  
Energy Requirement ◽  
Average Particle Size ◽  
High Energy ◽  
Energy Utilization ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Average Particle

AbstractPlatinum nanoparticles (Pt NPs) have attracted interest in catalysis and biomedical applications due to their unique structural, optical, and catalytic properties. However, the conventional synthesis of Pt NPs using the chemical and physical methods is constrained by the use of harmful and costly chemicals, intricate preparation requirement, and high energy utilization. Hence, this review emphasizes on the green synthesis of Pt NPs using plant extracts as an alternative approach due to its simplicity, convenience, inexpensiveness, easy scalability, low energy requirement, environmental friendliness, and minimum usage of hazardous materials and maximized efficiency of the synthesis process. The underlying complex processes that cover the green synthesis (biosynthesis) of Pt NPs were reviewed. This review affirms the effects of different critical parameters (pH, reaction temperature, reaction time, and biomass dosage) on the size and shape of the synthesized Pt NPs. For instance, the average particle size of Pt NPs was reported to decrease with increasing pH, reaction temperature, and concentration of plant extract.

scholarly journals High-Temperature Synthesis of Metal–Matrix Composites (Ni-Ti)-TiB2

2021 ◽  
Vol 11 (5) ◽  
pp. 2426
Author(s):  
Vladimir Promakhov ◽  
Alexey Matveev ◽  
Nikita Schulz ◽  
Mikhail Grigoriev ◽  
Andrey Olisov ◽  
...  
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Average Particle Size ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Currently, metal–matrix composite materials are some of the most promising types of materials, and they combine the advantages of a metal matrix and reinforcing particles/fibres. Within the framework of this article, the high-temperature synthesis of metal–matrix composite materials based on the (Ni-Ti)-TiB2 system was studied. The selected approaches make it possible to obtain composite materials of various compositions without contamination and with a high degree of energy efficiency during production processes. Combustion processes in the samples of a 63.5 wt.% NiB + 36.5 wt.% Ti mixture and the phase composition and structure of the synthesis products were researched. It has been established that the synthesis process in the samples proceeds via the spin combustion mechanism. It has been shown that self-propagating high-temperature synthesis (SHS) powder particles have a composite structure and consist of a Ni-Ti matrix and TiB2 reinforcement inclusions that are uniformly distributed inside it. The inclusion size lies in the range between 0.1 and 4 µm, and the average particle size is 0.57 µm. The obtained metal-matrix composite materials can be used in additive manufacturing technologies as ligatures for heat-resistant alloys, as well as for the synthesis of composites using traditional methods of powder metallurgy.

scholarly journals A Comparative Study of Nanostructures of CuO/Cu2O Fabricated via Potentiostatic and Galvanostatic Anodization

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
S. Mary Margaret ◽  
Albin John P. Paul Winston ◽  
S. Muthupandi ◽  
P. Shobha ◽  
P. Sagayaraj
Keyword(s):  
Thermal Stability ◽  
Comparative Study ◽  
Aqueous Electrolyte ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Molecular Vibration ◽  
Synthesis Process ◽  
Average Particle ◽  
Good Crystallinity ◽  
Cu Foil

A detailed comparative study on the synthesis process of coral-like CuO/Cu2O nanorods (NRs) and nanopolycrystals (NPCs) fabricated on Cu foil employing aqueous electrolyte via potentiostatic (POT) and galvanostatic (GAL) modes is discussed. The structural, morphological, thermal, compositional, and molecular vibration of the prepared CuO/Cu2O nanostructures was characterized by XRD, HRSEM, TG/DTA, FTIR, and EDX techniques. XRD analysis confirmed the crystalline phase of the formation of monoclinic CuO and cubic Cu2O nanostructures with well-defined morphology. The average particle size was found to be 21.52 nm and 26.59 nm for NRs (POT) and NPCs (GAL), respectively, and this result is corroborated from the HRSEM analysis. POT synthesized nanoparticle depicted a higher thermal stability up to 600°C implying that the potentiostatically grown coral-like NRs exhibit a good crystallinity and well-ordered morphology.

Preparation and Magnetic Properties of Carbon Encapsulated Fe-Cu Alloy Nanoparticles

2010 ◽  
Vol 177 ◽  
pp. 673-676 ◽  
Author(s):  
Jun Xue ◽  
Hou Kui Xiang ◽  
Hong Qiao Ding ◽  
Shu Li Pang ◽  
Xue Hua Wang ◽  
...  
Keyword(s):  
Magnetic Measurement ◽  
Average Particle Size ◽  
Soft Magnetic Property ◽  
Copper Nitrate ◽  
Synthesis Process ◽  
Ferric Nitrate ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Alloy

Carbon encapsulated Fe-Cu alloys nanoparticles were synthesized by using ferric nitrate, copper nitrate as metal sources and using sucrose as carbon source. The synthesis process involved a step of hydrazine hydrate reduction in alcohol solution and a step of annealing carbonization. The as-prepared samples were characterized by X-ray diffraction technique, X-ray energy dispersion spectrograph, trans- mission electron microscopy and Raman spectroscopy. The results showed the sample was core / shell structure, the metalic core was crystalline FeCu4 alloy, the shell was amorphous carbon, and the average particle size was about 51nm. The magnetic measurement by using a vibrating sample magnetometer revealed that the sample has ultra-soft magnetic property with the saturation magnetization Ms of 13.01 emu/g, residual magnetization Mr of 0.37 emu/g and coercive forces Hc of 54.43 Oe at room temperature.

Synthesis of Nanostructured Magnetic Mixed-Oxide Ferrite Powders by Using A Novel Chemical Method

2002 ◽  
Vol 720 ◽  
Author(s):  
N N Ghosh
Keyword(s):  
Particle Size ◽  
Mixed Oxide ◽  
Chemical Method ◽  
Average Particle Size ◽  
Cost Effective ◽  
Water Soluble ◽  
Average Particle ◽  
Chemical Route ◽  
Water Soluble Polymer ◽  
Different Temperatures

AbstractIn the present investigation, an attempt has been made to establish a new chemical route for synthesis of the nanostructured mixed oxide ferrite powders. By using this chemical method a variety of ferrite powders having spinel structure and doped with Co, Ni, Mn, Zn etc has been prepared. In this method nitrate salts of the different metals were used as starting materials. The aqueous solutions of the metal nitrates were mixed according to the molar ration of the compositions. Then the mixtures were mixed with an aqueous solution of water soluble polymer (polyvinyl alcohol). This mixture after drying yield fluffy brown powders. These powders were then calcined at different temperatures ranging from 400 °C to 700 °C. Nanostructured powders were obtained from the thermal decomposition of the brown powders. The powders, prepared by calcinations at different temperatures, were characterized by using X-Ray diffraction analysis, IR spectroscopy, TGA/DTA, and TEM. It was observed that the average particle size of the powders are in nanometer scale with a narrow size distribution. The average particle size of the powders was increased with the increase of calcinations temperature.This chemical method has proved to provide a convenient process for the preparation of nanostructured ceramic powders at comparatively low temperatures and offers the potential of being a simple and cost-effective route.

scholarly journals An Efficient Microwave-Assisted Synthesis Method of Novel Bi2O3 Nanostructure and Its Application As a High-Performance Nanocatalyst in Preparing Benzylidene Barbituric Acid Derivatives

2021 ◽  
Author(s):  
Mahdieh Yahyazadehfar ◽  
Enayatollah Sheikhhosseini ◽  
Sayed Ali Ahmadi ◽  
Dadkhoda Ghazanfari
Keyword(s):  
Barbituric Acid ◽  
Aqueous Media ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Synthesis Process ◽  
Microwave Assisted Synthesis ◽  
Average Particle ◽  
Short Period ◽  
High Yields ◽  
Barbituric Acid Derivatives

Abstract In this study, controllable and optimal microwave irradiation has been used to synthesize the novel nanostructures of Bi2O3 under environmental conditions. The final products had a thermal stability of 210 °C, an average particle size distribution of 85 nm, and surface area of 783 m2/g. The high thermodynamic stability of Bi2O3 nanostructures were confirmed by TG and DSC analyses. The nanostructure nature of compounds, most importantly, the use of effective, cost effective and rapid synthesis route of microwave have created significant physiochemical properties in the Bi2O3 products. These unexpected properties have made the possibility of potentials application of these products in various fields, especially in nanocatalyst applications. It is well-documented that, as Lewis acid, bismuth nanocatalyst exhibits a great catalytic activity for the green synthesis of some bio-active barbituric acid derivatives using precursors with electron-donating or –withdrawing nature in high yields (80-98%). After incorporating this catalyst into the aqueous media, all the reactions were completed within 2-3 min at room temperature. The main advantages of this method are practical facility, the availability of starting materials, and low costs besides the catalyst reusability. Additionally, the catalyst synthesis process may be carried in the aqueous media during a short period with medium to high yields. The obtained results have opened a new window for development of a novel nanocatalyst with practical application.

Preparation of Mirabilite Microparticles via the Anti-Solvent Recrystallization Process

2020 ◽  
Vol 20 (5) ◽  
pp. 3071-3077
Author(s):  
Da-Wei He ◽  
Zhou Wang
Keyword(s):  
Electron Microscopy ◽  
Average Particle Size ◽  
Average Particle ◽  
Recrystallization Process ◽  
Solvent Ratio ◽  
Mixing Ratio ◽  
Optimal Conditions ◽  
Single Factor ◽  
Stirring Time ◽  
Scanning Electron

Mirabilite microparticles was prepared via the anti-solvent recrystallization process. The solvent-antisolvent system was constructed by adding saturated aqueous solution of mirabilite into absolute ethanol. The best mixing mode and the mixing ratio, the stirring time and the droplet acceleration were selected by single factor experiments. Scanning electron microscopy (SEM) was used to characterize the generated mirabilite microparticles. The optimal one-factor conditions were solvent-anti-solvent ratio of 1:4, stirring for 40 min and droplet acceleration of 2 mL·min−1. Under the optimal conditions, the mirabilite microparticles with complete hexahedral form and uniform surface were obtained, the average particle size was about 5 μm.

YVO4: RE3+(RE = Eu, Sm, Dy, Er) nanophosphors: Facile hydrothermal synthesis, microstructure, and photoluminescence

2009 ◽  
Vol 24 (10) ◽  
pp. 3050-3056 ◽  
Author(s):  
Bing Yan ◽  
Jianhua Wu
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Electron Microscope ◽  
Hydrothermal Synthesis ◽  
Average Particle Size ◽  
Hydrothermal Process ◽  
Synthesis Process ◽  
Average Particle ◽  
Sodium Vanadate ◽  
Rare Earth Nitrates

YVO4: 10%RE3+(RE = Eu, Sm, Dy, Er) nanophosphors have been synthesized by a facile modified hydrothermal technology to obtain the high purity. The key procedure for this hydrothermal process is the adding order of precursors, in which excess sodium vanadate should be added in the solution of rare earth nitrates. The microstructure (crystal phase, morphology, particle size) of these phosphors are characterized by x-ray powder diffraction, scanning electron microscope, and transmission electron microscope, which indicates that there are some cube-like crystals with tetragonal zircon structure and the average particle size is approximately 40 nm. The luminescent behaviors for the four rare earth ion-activated YVO4nanophosphors have been studied, and, for YVO4: 10%Eu3+nanophosphors in particular, it is found that a different hydrothermal process influences the phase composition, microstructure, and photoluminescence. This result suggests that the hydrothermal synthesis process (by adding sodium vanadate to the solution of rare earth nitrates) is favorable for YVO4nanophosphor to obtain pure phase, small particle size, long luminescent lifetime, and high luminescence quantum efficiency.

scholarly journals Characterisation and Optical Studies of Copper Oxide Nanostructures Doped with Lanthanum Ions

2014 ◽  
Vol 14 (4) ◽  
pp. 49-60 ◽  
Author(s):  
G. Varughese ◽  
V. Rini ◽  
S.P. Suraj ◽  
K.T. Usha
Keyword(s):  
Particle Size ◽  
Copper Oxide ◽  
Average Particle Size ◽  
Band Gap Energy ◽  
Average Particle ◽  
Nano Materials ◽  
Chemical Route ◽  
Direct Band ◽  
Gap States ◽  
La Doped

AbstractCopper Oxide is an extensively studied group II-VI semiconductor with optical properties. It exhibits a wide variety of morphologies in the nano regime that can be grown by tuning the growth habit of the CuO crystal. CuO nano materials with an average particle size of 15-27 nm are synthesized by chemical route. XRD, SEM, FTIR UV-Vis and EDS characterize the samples. The percentage of doping material is confirmed from the EDS spectra. The average crystal size of the prepared CuO: La nanopowder is determined by XRD. The UV absorption spectra revealed the absorption edge at wavelength 389 nm indicating the smaller size of CuO:La nano particle. The optical direct band gap energy of doped CuO nanoparticle is found to be in the range 3.149 eV. The increasing red shift with decreasing particle size suggests that the defects responsible for the intra gap states are primarily surface defect. The La doped CuO is highly effective and can significantly enhance the photo catalytic degradation.

Preparation of Nanocrystalline Ba3(Ca1.18Nb1.82)O9-δ Powder with Sol-Gel Auto-Ignition Synthesis Process

2007 ◽  
Vol 280-283 ◽  
pp. 631-634 ◽  
Author(s):  
Xin Tai Su ◽  
Qing Zhi Yan ◽  
Chang Chun Ge
Keyword(s):  
Chemical Method ◽  
Average Particle Size ◽  
Combustion Process ◽  
Water Soluble ◽  
Synthesis Process ◽  
Average Particle ◽  
Wet Chemical Method ◽  
Solid Reaction ◽  
Reaction Method ◽  
Wet Chemical

Ba3(Ca1.18Nb1.82)O9-d (BCN18) powder was synthesized using a wet chemical method from mixtures of all water-soluble compounds including Ba, Ca and Nb-citrate. It has been found that NH4NO3 in the initial solutions plays an important role in controlling the enthalpy of low temperature combustion process as well as the gel decomposition temperature. Further steps include evaporating, drying and calcinating. The obtained gels were characterized by TG-DSC, and the powder was characterized with XRD, TEM and BET. The experimental results have indicated that the heating temperature was only 800°C for synthesizing the powder and the average particle size was only about 40-50 nm. Furthermore it was found that a pure BCN18 phase with complexperovskite structure was formed at 800°C, which was about 800°C lower than that of the traditional solid-reaction method. So it is more practical and more superior to the traditional solid-reaction method and the present wet-chemical method in alcohol salt system reported in literature.

Sign in / Sign up

Export Citation Format

Share Document