scholarly journals Purification of precursors of calcium orthophosphates synthesis by co-precipitation method

2021 ◽  
pp. 81-89
Author(s):  
M.V. Nikolenko ◽  
Keyword(s):  
Calcium Phosphates ◽  
Phosphoric Acid Solution ◽  
Alkaline Media ◽  
Precipitation Method ◽  
Target Product ◽  
Calcium Orthophosphates ◽  
Maximum Extraction ◽  
Acidic And Alkaline Media ◽  
Co Precipitation ◽  
Cacl2 Solution

The purification of the synthesis precursors of calcium phosphates from the toxic microimpurities Cu(II), Cd(II), As(III) and Pb(II) by co-precipitation with a part of the target product was studied. It was found that a maximum extraction of Cu(II), Cd(II) and As(III) from the CaCl2 solutions was achieved in the acidic and alkaline media. When precipitating calcium phosphates from the H3PO4 solutions, the following patterns regarding the degree of co-precipitation of the microimpurities with increase of pH were observed: the degree of co-precipitation of Cd(II) decreases rapidly, whereas the degree of the co-precipitation of As(III) goes through the maximum and Cu(II) is removed completely. Pb(II) ions are also completely removed in both CaCl2 and H3PO4 solutions. It was shown that in order to purify the CaCl2 solution, it is necessary to add at least 15 g of H3PO4 per 1 dm3 of the solution and then adjust pH to the value of 2.5 to 3.0 by neutralizing the solution with ammonia. In order to remove the impurities from the phosphoric acid solution, it is recommended to carry out the co-precipitation in two following stages: firstly, the ions of Cd(II), Cu(II) and Pb(II) are removed at pH of 6.0–6.5, which requires at least 4 g of CaCl2 per 1 dm3 of the acid, and then the arsenic residues are removed at pH of 8.0–8.25, which requires at least 13 g of CaCl2 per 1 dm3 of the solution.

Carboxymethylchitosan/Calcium Phosphate Hybrid Materials Prepared by an Innovative Auto-Catalytic Co-Precipitation Method

2005 ◽  
Vol 284-286 ◽  
pp. 701-704 ◽  
Author(s):  
S.A. Costa ◽  
J. Miguel Oliveira ◽  
Isabel B. Leonor ◽  
Rui L. Reis
Keyword(s):  
Calcium Phosphate ◽  
Calcium Phosphates ◽  
Precipitation Method ◽  
Porous Scaffolds ◽  
X Ray Diffraction ◽  
Polymer Precipitation ◽  
Acid Bath ◽  
The Fourier Transform ◽  
Xrd Patterns ◽  
Co Precipitation

In this study, it is shown that it is possible to prepare carboxymethyl-chitosan/Ca-P hybrids using an innovative “auto-catalytic” co-precipitation method, namely by using an acid and an oxidant bath. The X-ray diffraction (XRD) patterns evidenced the formation of crystalline calcium-phosphate precipitates when using an acid bath, while amorphous ones were obtained for those produced in the oxidant bath. The Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM/EDS) studies revealed that the extent of the polymer precipitation and formation of calcium-phosphates is directly dependent on the pH and composition of the baths. Furthermore, by conducting bioactivity tests in a simulated body fluid (SBF) followed by the SEM/EDS analysis it was possible to detect the formation of an apatite layer with a cauliflower-like morphology on the surface of hybrids prepared by the acid bath, after 7 days of immersion. These results are quite promising because they can allow for the production of bioactive and biodegradable 3D porous scaffolds to be used in bone tissue engineering applications.

Biomimetic Composites Based on Calcium Phosphates and Chitosan - Hyaluronic Acid with Potential Application in Bone Tissue Engineering

2013 ◽  
Vol 587 ◽  
pp. 191-196 ◽  
Author(s):  
Florina Daniela Ivan ◽  
Andreea Marian ◽  
Constantin Edi Tanase ◽  
Maria Butnaru ◽  
Liliana Verestiuc
Keyword(s):  
Tissue Engineering ◽  
Hyaluronic Acid ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Calcium Phosphates ◽  
Degradation Process ◽  
Precipitation Method ◽  
Negative Effect ◽  
Co Precipitation

Composites based on calcium phosphates (CP) and mixtures of biopolymers (chitosan and hyaluronic acid) have been prepared by a biomimetic co-precipitation method and tested as scaffolds for bone tissue engineering. The biomimetic strategy is inspired by natural mineralization processes, where the synthesized minerals are usually combined with proteins, polysaccharides or other mineral forms to form composite, in physiological conditions of temperature and pH. Fourier transformed infrared spectroscopy, scanning electron microscopy, X-ray diffraction and XPS analyses confirmed the porous morphology of the scaffolds and formation of various forms of calcium phosphates with amorphous nature. Thein vitrodegradation studies showed a slow degradation process for CP-biopolymers composites and limited swelling in simulated body fluids. The scaffolds compositions have no negative effect on osteoblasts cell, emphasizing a good biocompatibility.

Magnetic and dielectric properties of BiFeO3 nanoparticles

2015 ◽  
Vol 7 (2) ◽  
pp. 1393-1403
Author(s):  
Dr R.P VIJAYALAKSHMI ◽  
N. Manjula ◽  
S. Ramu ◽  
Amaranatha Reddy
Keyword(s):  
Diffuse Reflectance Spectrum ◽  
Precipitation Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Bifeo3 Nanoparticles ◽  
Transmission Electron ◽  
Multiferroic Bifeo3 ◽  
Pure Phase ◽  
Simple Chemical ◽  
Co Precipitation

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m.

Exploring the characterization of Ni doped MgO nanoparticles using co-precipitation method

2020 ◽  
Vol 3 (1) ◽  
pp. 30-33
Author(s):  
Muthulakshmi M ◽  
Madhumitha G
Keyword(s):  
Magnesium Oxide ◽  
Analytical Techniques ◽  
Nickel Chloride ◽  
Precipitation Method ◽  
Crystalline Powder ◽  
High Melting Point ◽  
Design Synthesis ◽  
Mgo Nanoparticles ◽  
Co Precipitation

Nanotechnology is a field of applied science focused on design, synthesis and characterization of nanomaterials. The nickel and magnesium have improved their applications in transparent electrodes and nano electronics. In addition, magnesium oxide has moisture resistance and high melting point properties. In the present work has been carried out in the development of green crystalline powder of nickel doped magnesium oxide nanoparticles by Co-precipitation method, from the mixture of nickel chloride and magnesium chloride with KOH as solvent. From the XRD results, crystalline size of the particle can be observed. Spherical structure of Ni doped MgO nanoparticles were indicated by SEM results and powdered composition of samples were obtained from FTIR. EDAX represents the peak composition of the nanoparticle. The above analytical techniques have confirmed that the Ni doped MgO nanoparticles obtained from the mixture of NiCl2 and MgCl2.

Diseases Prevention by Water Defluoridation Using Hydrotalcites as Decontaminant Materials

2017 ◽  
Vol 68 (1) ◽  
pp. 168-171 ◽  
Author(s):  
Letitia Doina Duceac ◽  
Cristina Elena Dobre ◽  
Ioana Pavaleanu ◽  
Gabriela Calin ◽  
Simona Nichitus ◽  
...  
Keyword(s):  
Dental Fluorosis ◽  
Precipitation Method ◽  
Original Structure ◽  
Fluoride Removal ◽  
Major Goal ◽  
Bone Stiffness ◽  
Morphological Aspects ◽  
Adsorption Capacities ◽  
Interlayer Structure ◽  
Co Precipitation

Preventing diseases is deemed to be the major goal of our century especially when an excessive fluoride in drinking water can cause dental fluorosis, bone stiffness, rheumatism and skeletal fluorosis. Fluoride uptake from groundwater implies a worldwide multidisciplinary effort in order to develop renewable, cheap, human friendly materials. Among other materials, hydrotalcites could be good candidates for an efficient fluoride removal from water due to their adsorption, anion exchange and reconstruction properties. These nanostructured materials were synthesized using co-precipitation method in controlled conditions. Presence of anions in the interlayer structure and morphological aspects were performed by FTIR and SEM techniques. Thermal treatment of hydrotalcites showed good adsorption capacities for water defluoridation mostly due to their tendency to restore the original structure.

Synthesis of highly sinterable YAG nanopowders by a modified co-precipitation method

2007 ◽  
Vol 433 (1-2) ◽  
pp. 328-331 ◽  
Author(s):  
Zhi-Hui Chen ◽  
Yun Yang ◽  
Zhang-Gui Hu ◽  
Jiang-Tao Li ◽  
Shu-Li He
Keyword(s):  
Precipitation Method ◽  
Co Precipitation

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.

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