Synthesis and Characterization of Nanostructured Ceramic Powders of Calcium Phosphate and Hydroxyapatite for Dental Applications

2008 ◽  
Vol 396-398 ◽  
pp. 619-622 ◽  
Author(s):  
Nelson Heriberto A. Camargo ◽  
S. de Lima ◽  
Julio C.P. Souza ◽  
Juliana F. de Aguiar ◽  
E. Gemelli ◽  
...  

In the last decades many investigations have been oriented toward the development of nanostructured biomaterials such as calcium phosphate ceramics, particularly those composed of stoicheiometric hydroxyapatite (Ca10(PO4)6(OH)2) and a-and β- tricalcium phosphate (Ca3(PO4)2), which present chemical and crystallographic similarities with hard tissues (bones and teeth). Because of these characteristics, these materials can be used for reconstitution and regeneration of bone tissues. The odontological and biomedical applications are still limited due to their brittle behaviour. This study was focused in the synthesis and characterization of a bone matrix of calcium phosphate (β-TCP) and hydroxyapatite (HAP-101 e HAp-201). The results presented here are related to the morphological characterization of nanostructured powders from scanning electron microscopy viewpoint. X-ray diffraction was used to identifier the present phases in the powders and the infrared spectrometry (FTIR) was used to analyse OH bonds from hydroxyapatite and PO4 from calcium phosphates.

2007 ◽  
Vol 12 (4) ◽  
pp. 574-582 ◽  
Author(s):  
Nelson Heriberto de Almeida Camargo ◽  
O. J. Bellini ◽  
Enori Gemelli ◽  
M. Tomiyama

Nanostructured materials have been largely studied in the last few years because they have a great potential to applications in different fields like physics, chemistry, biology, mechanic and medicine. Synthesis and characterization of nanostructured materials is a subject of great interest involving science, market, politicians, government and society. The nanostructured materials are in demand in biomedical area, mainly the bioceramics composed of calcium phosphates (Ca/P), which have an excellent biocompatibility and mineralogical characteristics similar to those of bones. The aim of this work was to optimize the method of powder synthesis of nanostructured calcium phosphate and of nanocomposites composed of calcium phosphate//SiO2n, containing 5, 10 and 15% (in volume) of nanometric silica (SiO2n). The results are expressed according to the method of synthesis, mineralogical and morphological characterization, and thermal behavior for the different compositions of the nanostructured powder synthesized.


2008 ◽  
Vol 396-398 ◽  
pp. 615-618
Author(s):  
Rodrigo Brandão ◽  
Fernando Pupio ◽  
Nelson Heriberto A. Camargo ◽  
E. Gemelli

The bioceramics nanostructured have made important characteristics in biomedical applications, especially the calcium phosphate ceramics. The aim of this work is synthesis and characterization of calcium phosphate and nanocomposites powders, the method of dissolution of CaO in liquid medium, precipitation and formation of bone calcium phosphate matrix, and nanocomposites by adding the solution of phosphoric acid (H3PO4). The nanocomposites powders were synthesized using as strengthening silica gel nanometer (20nm) at concentrations of 1%, 2%, 3% and 5% by volume and subjected to heat treatment to 900°C for 2 hours, seeking obtained HA (Hydroxyapatite). Later the bone matrix of calcium phosphate and nanocomposites powders were subjected from process attrition milling for 2 hours, by way of comparison. The studies characterizations were conducted through the technique of X-ray diffraction, scanning electron microscopy (SEM) and dilatometric test.


2019 ◽  
Vol 1 (2) ◽  
pp. 627-635 ◽  
Author(s):  
Mayuresh Keskar ◽  
Camila Sabatini ◽  
Chong Cheng ◽  
Mark T. Swihart

Synthesis of composite nanostructures of amorphous calcium phosphate loaded with silver nanoparticles has been achieved using a spray pyrolysis method. Upon incorporation into a commercial dental adhesive resin, these nanostructures provide sustained release of silver, calcium, and phosphate ions.


2016 ◽  
Vol 881 ◽  
pp. 153-158
Author(s):  
Marli Baltazar Roesler Eckstein ◽  
Nelson Heriberto Almeida Camargo ◽  
Camila Thais Mamani ◽  
Priscila Ferraz Franczak ◽  
Daiara Floriano-Silva ◽  
...  

Calcium phosphates bioceramics are a broad class of biomaterials, known by properties like biocompatibility and bioactivity in living tissues. The aim of this paper was the synthesis by wet method and characterization of nanostructured calcium phosphate powders in the Ca/P ratio of 1.67molar and rheological evaluation of the colloidal suspension during the synthesis: suspension viscosity with variable shear rate. Morphological characterization was performed for the hydrated nanostructured calcium phosphate powder by scanning electron microscopy with field effect, crystallography by X-Ray diffractometry, chemical characterization by Fourier Transformed Infrared Spectroscopy. The results demonstrated that varying the shear rate has a direct influence on the viscosity values according to time. This result may contribute to the development of a synthesis methodology for nanostructured calcium phosphate powders.


2016 ◽  
Vol 869 ◽  
pp. 884-889
Author(s):  
Nadia Sueli Vieira Capanema ◽  
Alexandra A.P. Mansur ◽  
Herman Sander Mansur

The need for obtaining new materials to replace human body parts that were destroyed or damaged led scientists from different areas of research for developing new biomaterials. Thus, the aim of this work was the synthesis and characterization of niobium-modified apatite bioceramics. Calcium phosphates (CaP) were synthesized with niobium partially replacing calcium sites using aqueous precipitation route at room temperature. The bioceramics, with and without Nb incorporation, were characterized by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) as prepared and after heat treatments The results indicated that Nb was incorporated in the apatite structure promoting morphological and structural changes in the ceramic properties.


2016 ◽  
Vol 881 ◽  
pp. 165-170
Author(s):  
Priscila Ferraz Franczak ◽  
Nelson Heriberto Almeida Camargo ◽  
Daiara Floriano-Silva ◽  
Marli Baltazar Roesler Eckstein ◽  
Maicon Douglas Possamai

The calcium phosphate bioceramics are characterized by chemical and crystallographic similarity with the human skeleton. The wet synthesis method was used in the preparation of hydrated calcium phosphate nanostructured powders and biphasic compositions of calcium phosphate matrix. This study aimed the synthesis and characterization of a hydrated calcium phosphate matrix in the ratio Ca/P 1.67 molar and two biphasic compositions of hydrated calcium phosphate matrix, with 1% MgO and 5% α-Al2O3. Scanning Electron Microscopy (SEM) helped with the powders morphological characterization, X-ray diffractometry (XRD) served for crystallographic characterization of powders and Fourier Transformed Infrared Spectroscopy (FTIR) gave support to the identification of H2O, CO32- and PO43- grouping vibrational bands. The work showed that the presence of 1% MgO inside the hydrated calcium phosphate matrix provided brushite formation and the presence of 5% α-Al2O3 in the matrix provided the hydrated calcium phosphate powder.


2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 721 ◽  
Author(s):  
Jorge A. Ramírez-Gómez ◽  
Javier Illescas ◽  
María del Carmen Díaz-Nava ◽  
Claudia Muro-Urista ◽  
Sonia Martínez-Gallegos ◽  
...  

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N′-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.


2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.


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