Hydroxyapatite Ceramics From Powders Prepared by Precipitation Method

1996 ◽  
Vol 432 ◽  
Author(s):  
Viviane V. Silva ◽  
Rosana Z. D. Fernandes
Keyword(s):  
Calcium Hydroxyapatite ◽  
Precipitation Method ◽  
Medical Implants ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Hydroxyapatite Powder ◽  
Hydroxyapatite Ceramics ◽  
Infra Red ◽  
Synthetic Hydroxyapatite

AbstractHydroxyapatite (HA), specifically, calcium hydroxyapatite, is the main inorganic compound of human bone and teeth. The utilization of synthetic powders of this material in dental and medical implants has increased in the recent days.In this paper, synthetic hydroxyapatite powder was prepared by a precipitation method, compacted and sintered at 800, 900, 1000, 1100, 1200 and 1300° C. The powder and its ceramics were analysed by X-ray diffraction, infra-red spectroscopy and scanning electron microscopy. The influence of experimental conditions on the microstructure and densification is discussed.Some measurements of the hydroxyapatite ceramics obtained in this work were compared with those of the hydroxyapatite ceramics produced from a commercial powder. It was shown that calcium hydroxyapatite is probably the only phase present for the precipitated samples sintered below 1100° C.

scholarly journals STRUCTURE CHARACTERIZATION OF CALCIUM DEFICIENT ELEMENT-SUBSTITUTED HYDROXYAPATITE WITH CONSTANT DOPANT RATIO OF DIFFERENT ELEMENTS

2020 ◽  
Vol 51 (5) ◽  
pp. 1420-1427
Author(s):  
Al-Sabbagh & et al.
Keyword(s):  
Single Phase ◽  
Atomic Radius ◽  
Calcium Hydroxyapatite ◽  
Structure Characterization ◽  
Precipitation Method ◽  
Vibration Modes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Groups

The element-substituted calcium Deficient hydroxyapatite samples were synthesized using liquid-phase precipitation method. Different element ions (Mg+2, Zn+2, and Cu+2) were added at constant ratio (5% wt.). The phase composition of the element-substituted calcium hydroxyapatite samples was investigated by using X-ray diffraction. A comparison with known characteristics of the synthetic ion-substituted forms of hydroxyapatite was conducted. It was determined, that the investigated materials are single-phase solid solutions of the element-substituted hydroxyapatite. By the methods of IR spectroscopy and Raman scattering (RS) it was discovered the dependence of incorporation of the carbonate anion that occupies a positions of phosphorus-oxygen groups in the hydroxyapatite structure as a result of embedding element ions (Zn+2, Cu+2, Mg+2) in the crystal lattice. Besides, It was determined, that the ratio of the intensities for the C03 group mode to the P04 groups mode depended on the nature of the element atom, which replace the calcium in the lattice of HAP, and reduced by substituting the calcium atoms by the atoms of Zn, Cu, and Mg from 0.15 to 0.06. Modeling of the vibration modes of Raman spectroscopy showed that incorporation of carbon atoms to the hydroxyapatite structure correlate with the Zn, Cu and Mg atomic radius, charge, and activity   

scholarly journals Influence of the Local Structure on the Photocatalytic Properties of Zinc Spinel Ferrite Nanoparticles

2021 ◽  
Author(s):  
Luciana Biazati ◽  
Lucas Lorenzini ◽  
Sandra Ferreira ◽  
Arilza Porto ◽  
Eustáquio de Castro ◽  
...  
Keyword(s):  
Uv Light ◽  
Spinel Ferrite ◽  
Indigo Carmine ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Tetrahedral Sites ◽  
Co Precipitation ◽  
X Ray Absorption

The correlation between iron distribution in octahedral or tetrahedral sites in synthetic magnetite and zinc spinel ferrites and their catalytic properties were investigated in this work. The zinc‑doped nanomagnetites were prepared by co-precipitation method and annealed at 420 °C. X-ray diffraction, UV-Vis, X-ray absorption and 57Fe Mössbauer spectroscopies were used to identify iron sites. The obtained results showed that ZnII replaces the relatively smaller FeIII cation in the tetrahedral sites, increasing the cubic lattice dimension, and this replacement remarkably enhances the catalytic effectiveness of the Zn-spinel ferrite towards the indigo carmine degradation compared to undoped magnetite. The indigo carmine degradation experiments were carried out using photo-Fenton method in which 50 mL of indigo carmine dye aqueous solutions (20 mg L−1, pH 3.0), 20 mg ZnxFe(3-x)O4, and 2.0 mL H2O2 (aqueous solution at 0.028 mol L−1) were placed under UV light at 25 °C. Under these experimental conditions the degradation rate of indigo carmine was superior to 98%.

scholarly journals Effects of pH value and Sintering Temperature on the Structural and Magnetic Properties of Barium Hexaferrites Prepared by Co-Precipitation

2021 ◽  
Vol 18 (1) ◽  
pp. 37-47
Author(s):  
Eman S. Al-Hwaitat ◽  
Mohammad K. Dmour ◽  
Ahmad S. Masadeh ◽  
Ibrahim Bsoul ◽  
Yazan Maswadeh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Permanent Magnet ◽  
Ph Value ◽  
Magnetic Measurements ◽  
Precipitation Method ◽  
Magnetic Data ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Co Precipitation

Barium hexaferrite (BaFe12O19; M-type; BaM) is an important, cost effective magnetic material for permanent magnet applications. The magnetic properties of the prepared samples, and the purity of the BaM phase depend critically on the synthesis route and experimental conditions. In this study, BaM hexaferrites were prepared by co-precipitation method using two different values of pH for the precursor solutions (11.0 and 12.5), and sintering pellets of the co-precipitates at 860, 920 and 990°C.The prepared samples were characterized using X-ray diffraction and magnetic measurements. X-ray diffraction patterns indicated that the samples prepared with pH = 12.5 consisted of a single BaM phase at all sintering temperatures. However, the patterns of the samples with pH = 11.0 did not reveal the existence of BaM at 860°C, whereasa major BaM phase (86 – 87 wt.%) was observed at 920 and 990°C with a minor α-Fe2O3 phase. The thermo magnetic curves confirmed the BaM magnetic phase in the samples. The hysteresis loops of the BaM samples showed characteristics of hard magnetic materials with relatively high saturation magnetization. Analysis of the magnetic data indicated an intrinsic coercivity Hci~ 5 kOe for all samples, and a saturation specific magnetization in the range σs = 56.0 – 66.3 emu/g, which are suitable for permanent magnet applications. The practical coercivity (HcB), residual induction (Br) and maximum energy product (BH)max of the samples with pH = 12.5 are higher than those of the samples with pH = 11.0, and the highest magnetic parameters of HcB = 1871 Oe, Br = 2384 G, and (BH)max = 8.92 kJ/m3 were observed for the sample with pH = 12.5 and sintered at 860°C.

In Vivo Behavior of Hydroxyapatite Evaluated by Attenuated Total Reflection Infrared Microscopy (ATR-FTIR)

2008 ◽  
Vol 396-398 ◽  
pp. 61-64 ◽  
Author(s):  
Monica Calasans-Maia ◽  
Silvia R. A. Santos ◽  
Antonella M. Rossi ◽  
José Mauro Granjeiro
Keyword(s):  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Infrared Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infra Red ◽  
Infrared Microscope ◽  
Synthetic Hydroxyapatite ◽  
Biological Environment

The study aimed the evaluation of the effect of osseous repair in the synthetic hydroxyapatite cylinder (HA) implanted in rabbit’s tibia. Fifteen adult animals, weighing around 2.5 and 3.0 Kg, sourced by the Fluminense Federal University Animal Lab were anesthetized with spinal anesthesia, and two perforations were created in right tibia and filled with cylinders (2 x 6 mm) of HA. The animals were killed after 28 days for evaluating the HA cylinder through attenuated total reflection infrared microscopy (ATR-FTIR). The two fragments of tibia with the cylinder were collected and fixed in alcohol 70° prior to dehydration in successive alcohol solutions and then impregnated and embedded in methyl-methacrylate. Not stained neither pasted to lamina, sections of 200 µm thickness were analyzed in a Shimadzu IRPrestige-21 Automatic Infrared Microscope (AIM-8800) with ATR Objective Mirror (ATR-8800M). Prior to implantation, HA cylinder was characterized by X-Ray diffraction (XRD), Attenuated Total Reflection- Infra Red microscopy (ATR-FTIR) and X-Ray Fluorescence (XRF). After the implantation, the spectrum of the ATR-FTIR at the interface to neoformed bone was acquired. The hydroxyapatite synthesized was crystalline and stoichiometric with Ca/P ratio of 1.66, becoming carbonated after 28 days of implantation. We conclude that attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a useful tool for biomaterial evaluation and able to detect the modification of the chemical HA cylinder pattern occurred probably by ions migration in the biological environment.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

PENGGUNAAN TiO2 PARTIKEL NANO HASIL SINTESIS BERBASIS AIR MENGGUNAKAN METODA SOL-GEL PADA BAHAN KAPAS SEBAGAI APLIKASI UNTUK TEKSTIL ANTI UV

Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sol Gel ◽  
Crosslinking Agent ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
X Ray ◽  
Infra Red ◽  
Scanning Electron

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.

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.

scholarly journals Zeolite NaP1 Functionalization for the Sorption of Metal Complexes with Biodegradable N-(1,2-dicarboxyethyl)-D,L-aspartic Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus
Keyword(s):  
Experimental Data ◽  
Aspartic Acid ◽  
Ph Value ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Modified Zeolite ◽  
X Ray ◽  
Slow Release Fertilizers ◽  
Pseudo Second Order

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.

A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

2021 ◽  
pp. 095441192199656
Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu
Keyword(s):  
Body Fluid ◽  
Xrd Analysis ◽  
Cold Isostatic Pressing ◽  
Expanded Perlite ◽  
X Ray Diffraction ◽  
Pressing Method ◽  
X Ray ◽  
Infra Red ◽  
Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

scholarly journals Microwave-Assisted Fabrication of Mesoporous Silica-Calcium Phosphate Composites for Dental Application

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 53
Author(s):  
Adrian Szewczyk ◽  
Adrianna Skwira ◽  
Marta Ginter ◽  
Donata Tajer ◽  
Magdalena Prokopowicz
Keyword(s):  
Calcium Phosphate ◽  
Mesoporous Silica ◽  
Octacalcium Phosphate ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Coating Solution ◽  
X Ray ◽  
Microwave Assisted ◽  
Calcium Orthophosphates ◽  
Different Types

Herein, the microwave-assisted wet precipitation method was used to obtain materials consisting of mesoporous silica (SBA-15) and calcium orthophosphates (CaP). Composites were prepared through immersion of mesoporous silica in different calcification coating solutions and then exposed to microwave radiation. The composites were characterized in terms of molecular structure, crystallinity, morphology, chemical composition, and mineralization potential by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). The application of microwave irradiation resulted in the formation of different types of calcium orthophosphates such as calcium deficient hydroxyapatite (CDHA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP) on the SBA-15 surface, depending on the type of coating solution. The composites for which the progressive formation of hydroxyapatite during incubation in simulated body fluid was observed were further used in the production of final pharmaceutical forms: membranes, granules, and pellets. All of the obtained pharmaceutical forms preserved mineralization properties.

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