Synthesis and Characterization of Mesoporous Hydroxyapatite

2010 ◽  
Vol 63 ◽  
pp. 152-157 ◽  
Author(s):  
Kien Seng Lew ◽  
Radzali Othman ◽  
Fei Yee Yeoh
Keyword(s):  
Self Assembly ◽  
Bone Cells ◽  
Hexagonal Phase ◽  
The Body ◽  
Precipitation Method ◽  
Hexadecyltrimethylammonium Bromide ◽  
Phosphate Solution ◽  
Decyltrimethylammonium Bromide ◽  
Constant Ph ◽  
Co Precipitation

Among the porous media, hydroxyapatite (HA) possesses good biocompatibility and bioactivity properties with respect to bone cells and tissues, due to its similarity with the hard tissues of the body. In this study, mesoporous HA was synthesized using a soft-templating technique via a self-assembly between HA and cationic surfactant decyltrimethylammonium bromide (C10TAB), which is analogous to the synthesis of mesoporous silica MCM-41. This co-precipitation method involved formation of hexagonal-phase micelle template by the surfactant and the precipitation of HA surrounding the micelle. After ageing, calcination was carried out to remove the templates, revealing the pores as well as to produce more crystalline and more stable HA structure. This study showed that instead of hexadecyltrimethylammonium bromide (C16TAB) which was conventionally used, C10TAB could also be used to synthesize single-phase mesoporous HA with pore size ca. 3 nm. Ageing temperature of 120 °C, for 24 hours was found sufficient for the formation of mesoporous HA. The adsorption properties of mesoporous HA was able to be improved by increasing the water content of C10TAB-phosphate solution and by constant pH adjustment during the mixing of solutions.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

Synthesis and Optical Properties of Annealed Cr Doped ZnS Nanoparticles

2013 ◽  
Vol 678 ◽  
pp. 163-167 ◽  
Author(s):  
D. Amaranatha Reddy ◽  
G. Murali ◽  
N. Madhusudhana Rao ◽  
R.P. Vijayalakshmi ◽  
B.K. Reddy
Keyword(s):  
Optical Properties ◽  
Hexagonal Phase ◽  
Blue Emission ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Structural And Optical Properties ◽  
Zns Nanoparticles ◽  
Blue Emission Peak ◽  
Co Precipitation ◽  
Surface Morphologies

Undoped and Cr doped ZnS nanoparticles with Cr concentrations of 3.0 at.% were prepared by a chemical co-precipitation method for the fist time, using 2-Mercaptoethanol as the capping agent and annealed the synthesized particles at 600°C for 3h in air. The effect of annealing on morphological, structural and optical properties of ZnS and ZnS:Cr have been studied and compared with as prepared samples. EDAX measurements confirmed the presence of Cr in the ZnS lattice and it also confirms the conversion of ZnS into ZnO after annealed at 600 0C/3h. Surface morphologies of all samples were characterized using scanning electron microscopy (SEM). XRD spectra of as synthesized nanoparticles of ZnS and ZnS:Cr exhibited cubic phase. After annealing, the cubic phase is transformed into hexagonal phase. The particle sizes of the ZnS:Cr powders were increased from 5 to 30 nm when the powders were annealed at 600°C. A stable blue emission peak at 445 nm is observed from the as prepared samples (pure ZnS and Cr doped ZnS) but annealed at 600 0C the PL peaked at 500 nm for pure ZnS and Cr doped ZnS nanoparticles exhibited PL peak at 500 nm as well as 654 nm. The emission intensity decreased in annealed particles compared to as synthesized samples.

Prominent Visible Light Photocatalytic and Water Purification Activity of PbS/CdS/CdO Nanocomposite Synthesized via Simple Co-Precipitation Method

2019 ◽  
Vol 9 (2) ◽  
pp. 278-284
Author(s):  
Mohammad Sabet ◽  
Marziyeh Mohammadi ◽  
Fatemeh Googhari
Keyword(s):  
Cadmium Sulfide ◽  
Water Solution ◽  
Hexagonal Phase ◽  
Wide Band ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Distilled Water ◽  
Hydrothermal Route ◽  
Sem Images ◽  
Co Precipitation

Background: Due to unique chemical and physical properties and potential application in many fields, nanostructured materials have attracted many attentions. Cadmium sulfide (CdS) is a semiconductor that has a wide band gap of 2.42 eV at room temperature and can be served in solar cells and photoluminescence devices. Cadmium sulfide (CdS) is a kind of attractive semiconductor material, and it is now widely used for optoelectronic applications. CdS nano and microstructures can be synthesized via different chemical methods such as microwave-solvothermal synthesis, surfactant-ligand coassisting solvothermal method and hydrothermal route. Also different morphologies of this semiconductor such as dendrites, nanorods, sphere-like, flakes, nanowires, flower-like shape triangular and hexagonal plates, were synthesized. Methods: To synthesis of the nanocomposite, a simple co-precipitation method was served. In briefly, 0.1 g of Pb(NO3)2 was dissolved in the distilled water (Solution 1). Also different aqueous solutions were made from dissolving different mole ratio of Cd(NO3)2.6H2O respect to the lead source in the water (Solution 2). Two solutions were mixed together under vigorous stirring and then S2- solution (0.02 g thiourea in the water) was added to the Pb2+/Cd2+ solution. After that 0.1 g of CTAB as surfactant was added to the final solution. Finally to the synthesis of both sulfide and oxide nanostructures, NaOH solution was added to the prepared solution to obtain pH= 10. Distilled water and absolute ethanol were used to wash the obtained precipitate and then it dried at 80 °C for 8 h. Results: From the XRD pattern it was found that the peaks placed at 24.9°, 27°, 44.1°, 48°, 52°, 54°, 57.8°, 66.8°, 71.2° are associated to CdS compound with hexagonal phase (JCPDS=00-001-0780) that belong to (100), (002), (110), (103), (112), (201), (202), (203), (211) Miller indices respectively. The Other peaks belong to PbS with hexagonal phase (JCPDS=01-078-1897), and CdO with cubic phase (JCPDS=00-001-1049). From SEM images, it was found by choosing the mole ratio to 1:1, very small and uniform particles were achieved. By increasing Pb2+/Cd2+ mole ratio to 1:2, very tiny particles aggregated together were achieved. Conclusion: The results showed that the product can adsorb extra 80% of heavy metal ions from the water. So it can be said that the nanocomposite can be used in the water treatment due to its high photocatalytic and surface adsorption activities. In other words, it can remove heavy metals from the water and also decompose organic pollutions.

A Green Route to Hexagonal and Monoclinic BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) Nanocrystallites for Tailoring Luminescent Performance

2016 ◽  
Vol 16 (4) ◽  
pp. 3547-3556 ◽  
Author(s):  
Errui Yang ◽  
Guangshe Li ◽  
Yunlong Zheng ◽  
Liping Li
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Monoclinic Phase ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
Formation Mechanisms ◽  
Optical Integrated Circuits ◽  
Green Route ◽  
Potential Applications ◽  
Co Precipitation

Selective synthesis of specific phased nanomaterials via a green route is a promising yet challenging task. In the present work, the hexagonal and monoclinic phases of BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) were prepared via room temperature co-precipitation method. For adjusting the phase of the products, the prepared mediums selected were the most common solvents, i.e., water and ethanol. It was very important that the prepared mediums could be easily recycled and reused by evaporating the filtrate. The formation mechanisms of hexagonal in water and monoclinic in ethanol were investigated. Interestingly, the growth behaviors of these phases were quite distinct and thus gave rise to distinct morphology and particle size. The hexagonal phase possesses a rod-like morphology with diameters of 50–160 nm and lengths of 65–400 nm while the monoclinic phase consists of almost entirely irregular nanoparticles. Also, it was found that the bending and stretching vibrations of O–H and PO4 tetrahedra were quite different for the products prepared in water and ethanol. Moreover, it was found that the luminescence properties, including emission intensity, lifetime, quantum efficiency, and color, could be readily tailored through controlling the phase structures and microstructures. The results showed that the monoclinic phase exhibited superior luminescent performance to the hexagonal phase. The methodologies reported in this work were fundamentally important, which could be easily extended to large-scale synthesis of other phased nanomaterials for potential applications as electroluminescent devices, optical integrated circuits, or biomarkers.

Effect of the synthesis method on the performance of Fe3O4–inositol hexaphosphate as a drug delivery vehicle for combination therapeutics with doxorubicin

2017 ◽  
Vol 41 (13) ◽  
pp. 5305-5312 ◽  
Author(s):  
Dandan Xu ◽  
Tongying Xu ◽  
Xuejie Guo ◽  
Qi Liu ◽  
Jingyuan Liu ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Self Assembly ◽  
Solvothermal Synthesis ◽  
Synthesis Method ◽  
Precipitation Method ◽  
Layer By Layer ◽  
Delivery Vehicle ◽  
Inositol Hexaphosphate ◽  
One Step ◽  
Co Precipitation

Fe3O4–IP6 was fabricated via layer-by-layer electrostatic self-assembly following a solvothermal synthesis method and via a one-step co-precipitation method.

Iron Doped Lanthanum Stannate Pyrochlores (La2Sn2-XFeXO7) for the Simultaneous Catalytic Removal NOx and Soot

2011 ◽  
Vol 306-307 ◽  
pp. 1468-1472 ◽  
Author(s):  
Zhong Peng Wang ◽  
Zi Zi Wang ◽  
Xiao Wang ◽  
Qian Li ◽  
Zong Gang Mu ◽  
...  
Keyword(s):  
Soot Oxidation ◽  
Redox Properties ◽  
Precipitation Method ◽  
Oxidation Activity ◽  
Structure Defects ◽  
Constant Ph ◽  
High Maximum ◽  
Co Precipitation ◽  
Catalytic Removal ◽  
Soot Oxidation Activity

A series of La2Sn2-xFexO7 (x=0, 0.2, 0.6, 1.0, 1.4, 1.8, 2.0) catalysts were prepared by a constant pH co-precipitation method, and their catalytic activity was investigated for simultaneous removal of NOx and soot. The incorporation of Fe strongly influences the crystal phase composition, surface area and redox properties of the catalysts. All the catalysts displayed soot oxidation activity with nearly 100% selectivity towards CO2. The doped solids exhibit higher activities than the undoped one, which may be related to the enhancement of reducibility derived from structure defects induced by doping. LSF0.6 may be a good catalyst with high soot oxidation activity (Ti = 334 °C) and a high maximum productivity of N2 (PN2= 12.4%).

scholarly journals Magnetite coupling in a PS/PMMA block copolymer using suspension polymerization

2020 ◽  
pp. 23-27
Author(s):  
Marco CARMONA-TORRES ◽  
Rosalba FUENTES-RAMÍREZ ◽  
David CONTRERAS-LOPEZ ◽  
Rosario GALINDO-GONZÁLEZ
Keyword(s):  
Block Copolymer ◽  
Polymer Matrix ◽  
Self Assembly ◽  
Suspension Polymerization ◽  
Ferromagnetic Material ◽  
Precipitation Method ◽  
Basic Medium ◽  
Ferrous Chloride ◽  
Magnetite Fe3o4 ◽  
Co Precipitation

The objective of the present article is to introduce nanoparticles of a ferromagnetic material (magnetite) to the polymer matrix. We will make some study to verify that the coupling of the nanoparticles in the material was carried out. The present work describes the self-assembly of nanocomposite in suspensión polymerization of PS/PMMA block copolymer, containing magnetite (Fe3O4) which is sonicated with the monomer mixture, with percentages of 0.25% and 0.5% in proportion of the weight of mixture. Photographs were taken with the microscope to verify the coupling of the ferromagnetic material to the polymer matrix, and to verify that couplig, we made characterization by infrared spectroscopy. Also describes the process of nanocomposite synthesis using co-precipitation method, in which ferric chloride and ferrous chloride are combined in an excess basic medium, to subsequently induce the precipitation of the material with a magnet.

Impact of Different Set of Precipitants on the Formation of BaFe12O19 Phase Nanomaterials

2020 ◽  
Vol 20 (6) ◽  
pp. 3486-3495 ◽  
Author(s):  
S. Balamurugan ◽  
S. P. Resmi ◽  
B. C. Brightlin ◽  
V. Sherly Arputha Kiruba ◽  
A. Reshma
Keyword(s):  
Intermediate Phase ◽  
Hexagonal Phase ◽  
Thermal Analyses ◽  
Crystalline Size ◽  
Precipitation Method ◽  
Average Crystalline Size ◽  
Magnetic Carriers ◽  
Amorphous Nature ◽  
Potential Applications ◽  
Co Precipitation

This work deals with the preparation of BaFe12O19 materials by soft chemical co-precipitation method using a different set of precipitants namely, (i) NaOH and Na2CO3, (ii) NH2CONH2 and NH4OH, and (iii) NH4HCO3 and NH4OH. The influence of these precipitants on the different properties is also investigated by various characterizations. The precipitants used in this work considerably affected the phase formation of BaFe12O19 materials. The thermal analyses reveal the thermal decomposition of the intermediate phase as well as the crystallization of BaFe12O19 phase. Due to the amorphous nature, all the co-precipitated products were annealed for 2 h at 1000 °C. Among the different annealed samples, the NaOH and Na2CO3 set of precipitant derived materials exhibit nearly single hexagonal phase of crystalline BaFe12O19 nanomaterials with an average crystalline size of ˜48 nm with a = 0.5888(4) nm and c = 2.320(2) nm. The particle size observed in micrograph was rather much higher than the average crystalline size obtained from XRD for the best sample. The BaFe12O19 nanomaterials studied in the present work have been found potential applications in magneto-optic recording media, biomolecular separations, magnetic carriers for drug targeting, permanent magnet, chip inductors, microwave absorbers, and hyperthermia cancer treatment.

Co-Precipitation Synthesis and Photoluminescence Properties of Sc0.88Lu0.05(V1-xPx)O4:Eu3+0.07 Red Phosphor for White Light Emitting Diodes

2018 ◽  
Vol 914 ◽  
pp. 87-95
Author(s):  
Di Wu ◽  
Xin Yu Ye ◽  
Xin Hua Yang ◽  
Fan Liu ◽  
Jian Wen Zhao ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Emission Intensity ◽  
Doping Concentration ◽  
Internal Quantum Efficiency ◽  
The Body ◽  
Precipitation Method ◽  
Luminescence Spectra ◽  
Red Phosphor ◽  
Light Emitting ◽  
Co Precipitation

Sc0.88Lu0.05(V1-xPx)O4:Eu3+0.07(0≤x≤0.5) phosphors were synthesized by co-precipitation method. The structure, morphology and luminescence spectra of samples were investigated by XRD, SEM and fluorescence spectrophotometer, respectively. The samples doped with Eu3+, Lu3+and PO43-can maintain the body-centered tetragonal structure of ScVO4and the morphology essentially remains unchanged with slight agglomeration. The excitation spectrum intensity of Sc0.88Lu0.05(V1-xPx)O4:Eu3+0.07increase within the near UV excitation (360-410nm). The optimum doping concentration of PO43-is 0.2(x value), and the maximum emission intensity of Sc0.88Lu0.05(V0.8P0.2)O4:Eu3+0.07is about 35 % higher than the Sc0.88Lu0.05VO4:Eu3+0.07under 365 nm excitation. Decay curve of5D0state for as-prepared samples fits the single order exponential behavior, the lifetime of5D0increase first and then decrease with the increase of PO43-doping concentration. The internal quantum efficiency is up to 66.73% under 365nm excitation, When the temperature rises to 200°C, the emission intensity maintains 79.3% of that in the room temperature. Sc0.88Lu0.05(V0.8P0.2)O4:Eu3+0.07phosphor shows high internal quantum efficiency and thermal stability, which is suitable for the UV-pumped white LED as red phosphor.

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