Comparison of Hydroxyapatite Synthesized under Different Conditions

2006 ◽  
Vol 510-511 ◽  
pp. 814-817 ◽  
Author(s):  
Li Rong Mo ◽  
Yu Bao Li ◽  
Guo Yu Lv ◽  
Ji Dong Li ◽  
Li Zhang

In this paper, using sodium phosphate and calcium nitrate as reagents, nano-hydroxyapatite (n-HA) was synthesised under 8 conditions. The morphology and crystallinity of these prepared HA were investigated by Transmission Electron Microscope (TEM) and X-ray diffraction pattern (XRD). The Ca/P molar ratio of n-HA was tested by chemical method. In order to find a better way to obtain purer nano-hydroxyapatite, the phases transition and purification of these 8 samples before and after sintering at 1000°C were compared. The results indicated that all these samples showed similar, poorly crystallized apatite structures before sintering. The adding order between calcium and phosphate would affect the crystallinity, structure and Ca/P molar ratio of hydoxyapatite significantly. XRD analysis showed that adding sodium phosphate into calcium nitrate could gain more HA phase after sintering at 1000°C. The pH of reaction system had obvious effects on the structure of hydroxyapatite. Besides the pH of reactants also affected the structure of hydoxyapatite.

2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).


2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.


Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1238
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Damian C. Onwudiwe

In this paper, spherical-shaped pure phase djurleite (Cu31S16) and roxbyite (Cu7S4) nanoparticles were prepared by a solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol (DDT). The reaction temperature was used to control the phases of the samples, which were represented as Cu31S16 (120 °C), Cu31S16 (150 °C), Cu7S4 (220 °C), and Cu7S4 (250 °C) and were characterized by using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and absorption spectroscopy. The samples were used as photocatalysts for the degradation of tetracycline (TC) under visible light irradiation. The results of the study showed that Cu7S4 (250 °C) exhibited the best activity in the reaction system with the TC degradation rate of up to 99% within 120 min of light exposure, while the Cu31S16 (120 °C) system was only 46.5% at the same reaction condition. In general, roxbyite Cu7S4 (250 °C) could be considered as a potential catalyst for the degradation of TC in solution.


Cerâmica ◽  
2016 ◽  
Vol 62 (364) ◽  
pp. 386-391 ◽  
Author(s):  
J. R. M. Ferreira ◽  
L. H. L. Louro ◽  
A. M. Costa ◽  
J. B. de Campos ◽  
M. H. Prado da Silva

Abstract In the present study, hydroxyapatite and Zn-substituted hydroxyapatite powders were synthesized using ostrich eggshell as a calcium source. The samples were analyzed by scanning electron microscopy with field emission gun, and X-ray diffraction (XRD) to identify the present phases, and X-ray fluorescence spectroscopy for quantitative chemical analysis of the synthesized and heat treated powders. The Fourier transform infrared spectroscopy technique was used before and after heat treatments at 700, 900 and 1100 °C in order to identify the functional groups present, as an additional technique to the XRD analysis. The results presented in this study represent a promising method for synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc, since the results showed no undesirable phases or impurities in the produced powders. It was observed that Zn-substituted hydroxyapatite showed higher thermal stability, when compared to pure hydroxyapatite.


2013 ◽  
Vol 1506 ◽  
Author(s):  
L. Wang ◽  
B. K. Rai ◽  
S. R. Mishra

AbstractNanostructured Al3+ doped Ni0.75Zn0.25Fe2-xAlxO4 (x = 0.0,0.2,0.4,0.6,0.8, and 1.0) ferrites were synthesized via wet chemical method. X-ray diffraction, transmission electron microscopy, and magnetization measurements have been used to investigate the structural and magnetic properties of spinel ferrites calcined at 950 °C .With the doping of Al3+, the particle size of Ni0.75Zn0.25Fe2-xAlxO4 first increased to 47 nm at x = 0.4 and then decreased down to 37 nm at x = 1. Saturation magnetization decreased linearly with Al3+ due to magnetic dilution. The coercive field showed an inverse dependence on the particle size of ferrites.


Author(s):  
Nguyen Ca ◽  
N. D Vinh ◽  
Phan Van Do ◽  
N. T. Hien ◽  
Xuan Hoa Vu ◽  
...  

Tb3+-doped ZnSe quantum dots (QDs) with Tb content in the range of 0.5 - 7% were successfully synthesized by a wet chemical method. X-ray diffraction (XRD) and transmission electron microscopy...


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2149
Author(s):  
Li-Ying Tseng ◽  
Erh-Chiang Chen ◽  
Jie-Mao Wang ◽  
Tzong-Ming Wu

A new biodegradable aliphatic-aromatic poly (butylene carbonate-co-terephthalate) (PBCT-85) with the molar ratio [BC]/[BT] = 85/15, successfully synthesized through transesterification and polycondensation processes, was identified using 1H-NMR spectra. Various weight ratios of PBCT/organically modified layered zinc phenylphosphonate (m-PPZn) nanocomposites were manufactured using the solution mixing process. Wide-angle X-ray diffraction and transmission electron microscopy were used to examine the morphology of PBCT-85/m-PPZn nanocomposites. Both results exhibited that the stacking layers of m-PPZn were intercalated into the PBCT-85 polymer matrix. The additional m-PPZn into PBCT-85 copolymer matrix significantly enhanced the storage modulus at −70 °C, as compared to that of neat PBCT-85. The lipase from Pseudomonas sp. was used to investigate the enzymatic degradation of PBCT-85/m-PPZn nanocomposites. The weight loss decreased as the loading of m-PPZn increased, indicating that the existence of m-PPZn inhibits the degradation of the PBCT-85 copolymers. This result might be attributed to the higher degree of contact angle for PBCT-85/m-PPZn nanocomposites. The PBCT-85/m-PPZn composites approved by MTT assay are appropriate for cell growth and might have potential in the application of biomedical materials.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Aidong Tang ◽  
Yuehua Deng ◽  
Jiao Jin ◽  
Huaming Yang

A novel nanocomposite ZnFe2O4-TiO2/MCM-41 (ZTM) was synthesized by a sol-gel method and characterized through X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N2adsorption-desorption, Raman spectroscopy, and ultraviolet visible (UV-vis) spectrophotometry. The results confirmed the incorporation of ZnFe2O4-TiO2nanoparticles inside the pores of the mesoporous MCM-41 host without destroying its integrity. ZnFe2O4nanoparticles can inhibit the transformation of anatase into rutile phase of TiO2. Incorporation of ZnFe2O4-TiO2within MCM-41 avoided the agglomeration of nanoparticles and reduced the band gap energy of TiO2to enhance its visible light photocatalytic activity. UV-vis absorption edges of ZTM nanocomposites redshifted with the increase of Zn/Ti molar ratio. The nanocomposite approach could be a potential choice for enhancing the photoactivity of TiO2, indicating an interesting application in the photodegradation and photoelectric fields.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.


2007 ◽  
Vol 124-126 ◽  
pp. 1229-1232 ◽  
Author(s):  
Myoung Seok Sung ◽  
Yoon Bok Lee ◽  
Yong Jin Kim ◽  
Yang Do Kim

Cadmium selenide(CdSe) nanoparticles were prepared in the aqueous solution containing isopropyl alcohol by the ultrasonic irradiation at room temperature. The cadmium chloride (CdCl2) and sodium selenosulfate (Na2SeSO3) were used as the cadmium and selenium source, respectively. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-Vis absorption spectra and PL spectra were used to characterize the CdSe nanoparticles. XRD analysis revealed the formation of cubic structure CdSe. TEM images showed aggregated CdSe nanoparticles with the size of nanometer scale. Average size of CdSe nanoparticles were about 3.9, 5.0 and 5.1nm with sonication time of 6, 30 and 40 minutes, respectively. The surface emission became less intensive and shifted to red with increasing irradiation time. This paper presents the effects of ultrasonic on the formation of CdSe nanoparticles and its characteristics.


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