scholarly journals A Study of Vanadate Group Substitution into Nanosized Hydroxyapatite Doped with Eu3+ Ions as a Potential Tissue Replacement Material

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 77
Author(s):  
Nicole Nowak ◽  
Rafal Jakub Wiglusz

In this study, nanosized vanadate-substituted hydroxyapatites doped with 1 mol% and 2 mol% Eu3+ ions were obtained via the precipitation method. To evaluate the structure and morphology of the obtained compounds, the XRPD (X-ray powder diffraction) technique, Rietveld refinement, SEM-EDS (scanning electron microscopy-energy-dispersive spectrometry) and TEM (transmission electron microscopy) techniques as well as FTIR (Fourier transform infrared) spectroscopy were performed. Moreover, the chemical formula was confirmed using the ICP-OES (Inductively coupled plasma optical emission spectroscopy spectroscopy). The calculated average grain size for powders was in the range of 25 to 90 nm. The luminescence properties of vanadium-substituted hydroxyapatite were evaluated by recording emission spectra and excitation spectra as well as luminescence kinetics. The crucial step of this research was the evaluation of the biocompatibility of the synthesized nanomaterials. Therefore, the obtained compounds were tested toward sheep red blood cells and normal human dermal fibroblast to confirm the nontoxicity and biocompatibility of new nanosized Eu3+ ion-doped vanadate-hydroxyapatite. Moreover, the final step of the research allowed us to determine the time dependent ion release to the simulated body fluid environment. The study confirmed cytocompatibility of vanadium hydroxyapatite doped with Eu3+ ions.

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 490
Author(s):  
Rudaviro Garidzirai ◽  
Phillimon Modisha ◽  
Innocent Shuro ◽  
Jacobus Visagie ◽  
Pieter van Helden ◽  
...  

The effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst were investigated for dehydrogenation of perhydrodibenzyltoluene (H18-DBT) as a liquid organic hydrogen carrier. Al2O3 supports were modified with Mg and Zn to produce Mg-Al2O3 and Zn-Al2O3 with a target loading of 3.8 wt.% for dopants. The modified supports were impregnated with chloroplatinic acid solution to produce the catalysts Pt/Al2O3, Pt/Mg-Al2O3 and Pt/Zn-Al2O3 of 0.5 wt.% Pt loading. Thereafter, the catalysts were characterised using inductively coupled plasma- optical emission spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, hydrogen temperature-programmed reduction, carbon-monoxide pulse chemisorption, ammonia temperature-programmed desorption, X-ray diffraction and transmission electron microscopy. The dehydrogenation experiments were performed using a horizontal plug flow reactor system and the catalyst time-on-stream was 22 h. Pt/Mg-Al2O3 showed the highest average hydrogen flowrate of 29 nL/h, while an average of 27 nL/h was obtained for both Pt/Al2O3 and Pt/Zn-Al2O3. This has resulted in a hydrogen yield of 80% for Pt/Mg-Al2O3, 71% for Pt/Zn-Al2O3 and 73% for Pt/Al2O3. In addition, the conversion of H18-DBT ranges from 99% to 92%, Pt 97–90% and 96–90% for Pt/Mg-Al2O3, Pt/Zn-Al2O3 and Pt/Al2O3, respectively. Following the latter catalyst order, the selectivity to dibenzyltoluene (H0-DBT) ranges from 78% to 57%, 75–51% and 71–45%. Therefore, Pt/Mg-Al2O3 showed improved catalytic performance towards dehydrogenation of H18-DBT.


2020 ◽  
Vol 10 (6) ◽  
pp. 6837-6845

β-tricalcium phosphate (β-TCP) is a bioceramic with unique osteoinductive and osteoconductive properties. It can be obtained by calcining calcium-deficient apatites (CDHA) at 750°C and above. The reduction of calcining temperature or the stabilization of the β phase, by doping, is therefore of particular interest. This paper investigates the preparation of CDHA with a theoretical 0.05 Mg/(Ca + Mg) ratio and (Ca+Mg)/P = 1.55 via precipitation method, and the resultant powder is calcined at a different temperature ranging from 80 to 715°C. The as-synthesized undoped powder was used as the reference in this study. The effect of calcination temperature and composition were investigated by the aid of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma optical emission spectroscopy (ICP-OES) and scanning electron microscopy (SEM). The study indicated that the powder was pure Mg-doped beta-tricalcium phosphate. The incorporation of Mg within the calcium phosphate lattice promoted the formation and stabilization of the β -TCP phase at a lower temperature.


Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1130
Author(s):  
Zhen Wang ◽  
Liping Xia ◽  
Jinlong Chen ◽  
Lili Ji ◽  
Yarui Zhou ◽  
...  

In this work, a SiO2-doped natural photocatalyst derived from waste mussel shell (HAS) was prepared by acidification. The as-prepared sample was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV-visible diffuse-reflectance spectrum (UV-vis DRS), and Differential scanning and thermogravimetric analyses (DTA/TGA). The results exhibited that HAS was mesopores nanomaterial consisting of uneven arranged rod-like structure, the dominant component of HAS was SiO2 with a large number of hydroxyl groups, and a variety of transition metals uniformly distributed in HAS. Rhodamine B (RhB) and methylene blue (MB) removal efficiencies (equal to 92.59% and 99.14%, respectively) were observed under the HAS presence when exposed to the visible light. The degradation products were analyzed using liquid Chromatograph Mass Spectrometer (LC-MS) and Total Organic Carbon (TOC), among which, MB was degraded by demethylation and deamination, and RhB was degraded by N-deethylation and conjugate structure destruction. After four successive recycles, the removal efficiency of RhB and MB are still reach 86.103% and 75.844%. This study indicated that the mussel shells might be suggested as a novel natural photocatalyst in the application of dye wastewater treatment.


2018 ◽  
Vol 941 ◽  
pp. 236-244 ◽  
Author(s):  
Chrysoula Ioannidou ◽  
Zaloa Arechabaleta ◽  
Arjan Rijkenberg ◽  
Robert M. Dalgliesh ◽  
A.A. van Well ◽  
...  

Nanosteels are used in automotive applications to accomplish resource-efficiency while providing high-tech properties. Quantitative data and further understanding on the precipitation kinetics in Nanosteels can contribute to fulfil this goal. Small-Angle Neutron Scattering measurements are performed on a Fe-C-Mn-V steel, previously heat-treated in a dilatometer at 650°C for several holding times from seconds to 10 hours. The evolution of the precipitate volume fraction, size distribution and number density is calculated by fitting the experimental Small-Angle Neutron Scattering curves. The effect of phase transformation on precipitation kinetics is also discussed. Complementary Transmission Electron Microscopy, Scanning Electron Microscopy and Inductively Coupled Plasma Optical Emission Spectroscopy measurements are performed to support the Small-Angle Neutron Scattering data analysis.


2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.


Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 943
Author(s):  
Indu Ambat ◽  
Varsha Srivastava ◽  
Esa Haapaniemi ◽  
Mika Sillanpää

The present work incorporates the synthesis of a multifunctional catalyst for the transesterification of waste cooking oil (WCO) to biodiesel and recovery of rare earth elements (REEs). For this purpose, TiO2 nanoparticles and TiO2 doped with lithium ions were prepared. The influence of lithium ions on the catalytic performance of TiO2 was attained by impregnation of the different molar ratios of lithium hydroxide to bare TiO2. Then each catalyst was screened for catalytic conversion of WCO to fatty acid methyl ester (FAME) and also for REEs recovery. All synthesized materials were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, and Hammett indicator for the basicity test. The obtained biodiesel was characterized by gas chromatography with mass spectrometry (GC-MS), 1H, and 13C nuclear magnetic resonance (NMR). Moreover, the physical parameters of the synthesized biodiesel were also determined. The REEs recovery efficiency of synthesized nanomaterials was investigated, and the percentage of REEs removal was determined by inductively-coupled plasma optical emission spectroscopy (ICP-OES).


2010 ◽  
Vol 63 (5) ◽  
pp. 830 ◽  
Author(s):  
Martin Lerch ◽  
Thorsten Ressler ◽  
Frank Krumeich ◽  
Jean-Pierre Cosson ◽  
Edouard Hnawia ◽  
...  

A wood sample of the nickel hyperaccumulator tree Sebertia acuminata Pierre ex. Baillon was pyrolyzed in an inert atmosphere to produce a charcoal-like material containing nanoparticulate nickel. Its overall nickel content was determined to be ~7 wt-% by wet chemical analysis (acid digestion, inductively coupled plasma optical emission spectroscopy). Depending on the conditions of pyrolysis (5 h at 800°C; or 5 h at 800°C followed by 7 h at 900°C), the average crystallite sizes were ~7 and 42 nm, respectively, as determined by X-ray powder diffraction (XRD) and electron microscopy (scanning, scanning transmission, and transmission). Furthermore, high resolution transmission electron microscopy images reveal that the Ni particles are, in some cases, encapsulated with graphitic carbon layers of varying thickness. Scanning electron microscopy results indicate for the most part, a preservation of the wood framework and a remarkably uniform distribution of the nickel nanoparticles in the vessels of the xylem. XRD and X-ray absorption fine structure analysis reveal the presence of NiO besides Ni.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mansoureh Daraie ◽  
Majid M. Heravi ◽  
Yalda Rangraz ◽  
Zahra Besharati

AbstractA hybrid system was designed and synthesized through reacting modified halloysite (Hal-Cl) with Schiff base (DAB-PC) and applied as catalytic support for anchoring Pd NPs to afford Pd@Hal-DAB-PC catalyst. The resultant material was well identified by various analyses including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction patterns (XRD), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and inductively coupled plasma-optical emission spectrometry (ICP-OES) and revealed outstanding catalytic activity in the Sonogashira reaction in aqueous media. Also, This nanocatalyst was simply collected and recycled up to six runs with a slight drop in efficiency, indicating the durability of Pd@Hal-DAB-PC.


2019 ◽  
Vol 72 (9) ◽  
pp. 693
Author(s):  
Maryam Mohammadikish ◽  
Zohreh Zafari ◽  
Susan Torabi

Uniform zinc-containing infinite coordination polymer (ICP) nanoparticles were achieved via a straightforward and rapid precipitation method in 5min, from a bi-thioglycolate functionalized salpn ligand (salpn=N,N′-bis(salicylidene)-1,3-propanediamine) as linker and zinc acetate. Characterization of the resulting product was performed by CHN elemental analysis, inductively coupled plasma–optical emission spectroscopy, FT-IR spectroscopy, thermogravimetric analysis, electron microscopies (FE-SEM and HR-TEM), and photoluminescence spectroscopy. Elemental analyses verified the proposed structure for the ICP with a 1:2 ratio of the salpn type ligand and Zn2+ ion. FE-SEM, TEM, and AFM analyses unveiled the existence of nanoparticles with diameters of ~30nm. PL spectroscopy showed a blue shift in emission peak of the ICP with regards to the organic ligand. The obtained ICP was utilized as a precursor to synthesize ZnO nanoparticles with wurtzite structure. An increase in bandgap of the prepared ZnO nanoparticles was observed in comparison with bulk ZnO as a result of quantum confinement of photogenerated electron–hole pairs. This method can be exploited for the synthesis of other coordination polymer micro/nanostructures.


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