scholarly journals Development of a chemical-free floatation technology for the purification of vein graphite and characterization of the products

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gamaralalage R. A. Kumara ◽  
Herath Mudiyanselage G. T. A. Pitawala ◽  
Buddika Karunarathne ◽  
Mantilaka Mudiyanselage M. G. P. G. Mantilaka ◽  
Rajapakse Mudiyanselage G. Rajapakse ◽  
...  
Keyword(s):  
Fine Particles ◽  
Xrd Analysis ◽  
Electron Microscopic ◽  
Tem Analysis ◽  
Environmental Friendliness ◽  
X Ray ◽  
Transmission Electron ◽  
Edge Defects ◽  
Crystallite Sizes ◽  
Notable Increase

AbstractA novel and simple flotation technique has been developed to prepare high-purity graphite from impure graphite. In this method, a suspension of pristine powdered graphite (PG) is dispersed and stirred in water without adding froth formers or supportive chemicals. This makes fine particles of graphite move upwards and float on water. X-ray diffraction (XRD) analysis reveals that the floated graphite (FG) has a lower c-axis parameter, indicating the removal of interlayer impurities. A notable increase in the intensity ratio of the D band to G band in the Raman spectra indicates that the FG has more edge defects due to their smaller crystallite sizes. Transmission electron microscopic (TEM) analysis shows the number of layers in FG has been reduced to 16 from 68 in PG. The absence of C=O vibration of Fourier Transformed Infrared (FT-IR) spectroscopy in treated and untreated samples suggests that their layers are not significantly oxidized. However, X-ray photoelectron spectroscopic (XPS) analysis shows the presence of C–O–C ether functionalities, possibly on edge planes. Further, the product has higher purity with increased carbon content. Therefore, the technique is helpful for the value enhancement of graphite, the reduction of the chemical cost of the conventional techniques, environmental friendliness, and improvement of its applications.

scholarly journals Development of a Chemical-free Floatation Technology for the Purification of Vein Graphite and Characterization of the Products

2021 ◽  
Author(s):  
Gamaralalage R. A. Kumara ◽  
Herath Mudiyanselage G. T. A. Pitawala ◽  
Buddika Karunarathne ◽  
Mantilaka Mudiyanselage M. G. P. G. Mantilaka ◽  
Rajapakse Mudiyanselage G. Rajapakse ◽  
...  
Keyword(s):  
Fine Particles ◽  
Xrd Analysis ◽  
Electron Microscopic ◽  
Tem Analysis ◽  
Environmental Friendliness ◽  
X Ray ◽  
Transmission Electron ◽  
Edge Defects ◽  
Crystallite Sizes ◽  
Notable Increase

Abstract A novel and simple flotation technique has been developed to prepare high-purity graphite from impure graphite. In this method, a suspension of powdered graphite (PG) is dispersed and stirred in water without adding froth formers or supportive chemicals. This makes fine particles of graphite to move upwards and float on water. X-ray diffraction (XRD) analysis reveals that the floated graphite (FG) has a lower c-axis parameter, indicating the removal of interlayer impurities. A notable increase in the intensity ratio of the D band to G band in the Raman spectra indicates that the FG has more edge defects due to their smaller crystallite sizes. Transmission electron microscopic (TEM) analysis shows the number of layers in FG has been reduced to 16 from 68 in PG. The absence of C = O vibration of Fourier Transformed Infrared (FT-IR) spectroscopy in treated and untreated samples suggests that layers of them are not significantly oxidized. However, X-ray photoelectron spectroscopic (XPS) analysis shows the presence of C-O-C ether functionalities, possibly on edge planes. Further, the product has higher purity with increased carbon content. Therefore, the technique is useful in the value enhancement of graphite, the reduction of the chemical cost of the conventional techniques, environmental friendliness, and improvement of its applications.

Fabrication of Mesoporous Cerium Dioxide Films by Cathodic Electrodeposition

2007 ◽  
Vol 7 (11) ◽  
pp. 4198-4201 ◽  
Author(s):  
Young-Soo Kim ◽  
Jin-Kyu Lee ◽  
Jae-Hoon Ahn ◽  
Eun-Kyung Park ◽  
Gil-Pyo Kim ◽  
...  
Keyword(s):  
Small Angle ◽  
Cerium Dioxide ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Cubic Phase ◽  
Tem Analysis ◽  
X Ray ◽  
Cathodic Electrodeposition ◽  
Glass Substrates ◽  
Transmission Electron

Mesoporous cerium dioxide (Ceria, CeO2) thin films have been successfully electrodeposited onto ITO-coated glass substrates from an aqueous solution of cerium nitrate using CTAB (Cetyltrimethylammonium Bromide) as a templatingagent. The synthesized films underwent detailed characterizations. The crystallinity of synthesized CeO2 film was confirmed by XRD analysis and HR-TEM analysis, and surface morphology was investigated by SEM analysis. The presence of mesoporosity in fabricated films was confirmed by TEM and small angle X-ray analysis. As-synthesized film was observed from XRD analysis and HR-TEM image to have well-crystallized structure of cubic phase CeO2. Transmission electron microscopy and small angle X-ray analysis revealed the presence of uniform mesoporosity with a well-ordered lamellar phase in the CeO2 films electrodeposited with CTAB templating.

scholarly journals Synthesis, Characterization, and Photocatalytic Performance of Mesoporous α-Mn2O3 Microspheres Prepared via a Precipitation Route

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Thermal Transformation ◽  
Xrd Analysis ◽  
Structural Deformation ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Transmission Electron

α-Mn2O3 microspheres with high phase purity, crystallinity, and surface area were synthesized by the thermal decomposition of precipitated MnCO3 microspheres without the use of any structure directing agents and tedious reaction conditions. The prepared Mn2O3 microspheres were characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) and photoluminescence (PL) studies. The complete thermal transformation of MnCO3 to Mn2O3 was clearly shown by the FTIR and XRD analysis. The electron microscopic images clearly confirmed the microsphere-like morphology of the products with some structural deformation for the calcined Mn2O3 sample. The mesoporous texture generated from the interaggregation of subnanoparticles in the microstructures is visibly evident from the TEM and BET studies. Moreover, the Mn2O3 microstructures showed a moderate photocatalytic activity for the degradation of methylene blue dye pollutant under UV light irradiation, using air as the potential oxidizing agent.

The Hydrothermal Synthesis of ZrO2 Nanoparticles and their Optical Absorption Properties

2013 ◽  
Vol 873 ◽  
pp. 164-167
Author(s):  
Xiao Ming Fu
Keyword(s):  
Optical Absorption ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Ammonia Water ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Absorption Spectroscopy

ZrO2 nanoparticles with a diameter range of less than 10 nm are successfully synthesized with zirconium nitrate as zirconium source and stronger ammonia water as precipitant at 210 °C for 48 h via the easy hydrothermal method. The phase, the morphologies and optical absorption properties of the samples have been characterized and analyzed by X-ray diffraction (XRD), field-emission transmission electron microscopy (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS), respectively. XRD analysis shows that the phase of as obtained samples is ZrO2. TEM analysis confirms that using stronger ammonia water as precipitant instead of NaOH and the increase of the reaction temperature are in favor of the synthesis of ZrO2 nanoparticles. And UV-VIS measurements show that ZrO2 nanoparticles have a good optical absorption property.

The Influence of the Hydrothermal Temperature on the Morphologies and the Optical Absorption Properties of M-ZrO2 Nanoparticles

2013 ◽  
Vol 320 ◽  
pp. 11-14
Author(s):  
Xiao Ming Fu
Keyword(s):  
Optical Absorption ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Absorption Spectroscopy

M-ZrO2 nanoparticles with a diameter range of about 10 nm are successfully synthesized with zirconium nitrate as zirconium source and stronger ammonia water as precipitant at 210 °C for 48 h via the easy hydrothermal method. The phase, the morphologies and optical absorption properties of the samples have been characterized and analyzed by X-ray diffraction (XRD), field-emission transmission electron microscopy (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS), respectively. XRD analysis shows that the phase of as obtained samples is M-ZrO2. TEM analysis confirms that the increase of the reaction temperature is in favor of the synthesis of M-ZrO2 nanoparticles. And UV-VIS measurements show that M-ZrO2 nanoparticles have a good optical absorption property.

Study of Precipitation Hardening in Two Al-Mg-Si Alloys with and without Copper and Excess Silicon Using Kissinger and Boswell Methods

2019 ◽  
Vol 397 ◽  
pp. 101-110
Author(s):  
Fares Serradj ◽  
Hichem Farh ◽  
Brahim Belfarhi
Keyword(s):  
Isoconversional Methods ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Electron Microscopic ◽  
X Ray ◽  
Excess Silicon ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Dsc Curves

The precipitation of two 6xxx (Al-Mg-Si) alloys with and without copper (Cu) and excess silicon (Si) has been investigated by using the differential scanning calorimetry (DSC), transmission electron microscopic (TEM) and X ray diffraction (XRD) analysis. The analysis of the DSC curves found that the excess Si accelerate the precipitation. The values of activation energies for each peak of DSC curves were determined by using Kissinger–Akahira–Sunose (KAS) and Boswell isoconversional methods. The alloy which has an excess Si and copper require larger activation energy for precipitation despite the acceleration of the precipitation by the excess Si. TEM observation result shows there is smaller size and higher density of precipitate in excess Si alloy than those of excess-free.

The effect of Tin additionon on Structural and magnetic properties of the stannoferrite Li0.5+0.5XFe2.5-1.5XSnXO4

2016 ◽  
Vol 12 (3) ◽  
pp. 4307-4321 ◽  
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Abbas
Keyword(s):  
Particle Size ◽  
Fine Particles ◽  
Magnetic Moments ◽  
Lithium Ferrite ◽  
Tem Analysis ◽  
Weiss Temperature ◽  
X Ray ◽  
Two Phases ◽  
Nanocrystalline Ferrite ◽  
20 Nm

The physical properties of ferrites are verysensitive to microstructure, which in turn critically dependson the manufacturing process.Nanocrystalline Lithium Stannoferrite system Li0.5+0.5XFe2.5-1.5XSnXO4,X= (0, 0.2, 0.4, 0.6, 0.8 and 1.0) fine particles were successfully prepared by double sintering ceramic technique at pre-sintering temperature of 500oC for 3 h andthepre-sintered material was crushed and sintered finally in air at 1000oC.The structural and microstructural evolutions of the nanophase have been studied using X-ray powder diffraction (XRD) and the Rietveld method.The refinement results showed that the nanocrystalline ferrite has a two phases of ordered and disordered phases for polymorphous lithium Stannoferrite.The particle size of as obtained samples were found to be ~20 nm through TEM that increases up to ~ 85 nmand isdependent on the annealing temperature. TEM micrograph reveals that the grains of sample are spherical in shape. (TEM) analysis confirmed the X-ray results.The particle size of stannic substituted lithium ferrite fine particle obtained from the XRD using Scherrer equation.Magneticmeasurements obtained from lake shore’s vibrating sample magnetometer (VSM), saturation magnetization ofordered LiFe5O8 was found to be (57.829 emu/g) which was lower than disordered LiFe5O8(62.848 emu/g).Theinterplay between superexchange interactions of Fe3+ ions at A and B sublattices gives rise to ferrimagnetic ordering of magnetic moments,with a high Curie-Weiss temperature (TCW ~ 900 K).

scholarly journals Functional Attributes of Myco-Synthesized Silver Nanoparticles from Endophytic Fungi: A New Implication in Biomedical Applications

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 473
Author(s):  
Prabu Kumar Seetharaman ◽  
Rajkuberan Chandrasekaran ◽  
Rajiv Periakaruppan ◽  
Sathishkumar Gnanasekar ◽  
Sivaramakrishnan Sivaperumal ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Culture Filtrate ◽  
Morphological Changes ◽  
Xrd Analysis ◽  
Penicillium Oxalicum ◽  
Breast Cancer Cell Lines ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
X Ray ◽  
Average Size

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV–vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.

scholarly journals Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Test Sample ◽  
In Vitro Cytotoxicity ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

Effect of Synthesis Temperature on Particles Size and Morphology of Zirconium Oxide Nanoparticle

2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Zirconium Oxide ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Ft Ir

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.

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