scholarly journals Y2O3:Eu3+ Nanophosphor-Coated Mica or TiO2/Mica as Red-Emitting Pearl Pigment: Coating Factors, Luminescent and Gloss Properties

2021 ◽  
Vol 11 (10) ◽  
pp. 4365
Author(s):  
Se-Min Ban ◽  
Mahboob Ullah ◽  
Kyeong Youl Jung ◽  
Byung-Ki Choi ◽  
Kwang-Jung Kang ◽  
...  
Keyword(s):  
Electrostatic Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Process ◽  
Red Color ◽  
Chromaticity Coordinates ◽  
Bead Mill ◽  
Coating Method ◽  
Cie Chromaticity ◽  
Fluorescence Spectrometer

Red-emitted Y2O3:Eu3+ nanophosphor coated on a mica flake (Y2O3:Eu@MF) or on TiO2 having a rutile crystalline mica flake (Y2O3:Eu@TMF) has been prepared by an electrostatic interaction with the wet-coating method for the purpose of a pigment with luminescent and gloss properties. Aggregated Y2O3:Eu3+, prepared by the template method, was dispersed into nanosol by a controlled bead-mill wet process. The (+) charged Y2O3:Eu3+ nanosol was effectively coated on the (-) charged mica flake (MF) or the TiO2/mica flake (TMF) by an electrostatic interaction between the Y2O3:Eu3+ nanoparticles and MF or TMF at pH 6–8. The coating factors of Y2O3:Eu@MF were also studied and optimized by controlling the pH, stirring temperature, calcination temperature, and coating amount of Y2O3:Eu3+. The Y2O3:Eu3+ was partially coated and optimized on the MF or TMF surface with a coating coverage of about 40–50% or 60–70%, respectively. Y2O3:Eu@MF and Y2O3:Eu@TMF were exhibiting the luminescent property of a red color under a 254 nm wavelength, and had a color purity of over 95% according to CIE chromaticity coordinates. These materials were characterized by X-ray diffraction, FE-SEM, zeta potential, and a fluorescence spectrometer. These materials with luminescent and gloss properties prepared in this work potentially meet their applications for security purposes.

scholarly journals Synthesis and Characterization of a Novel Sm+3 Activated NaCdVO4 Phosphors for Red Emitting Material

2021 ◽  
Author(s):  
Marwa Enneffati ◽  
Mohammed Rasheed ◽  
Narjes Aouani ◽  
Bassem Louati ◽  
Kamel Guidara ◽  
...  
Keyword(s):  
Solid State Reaction Method ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
White Leds ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
Simple Solid State Reaction ◽  
Reflectance Data

Abstract Sm3+ activated NaCdVO4 phosphors were prepared by the simple solid-state reaction method. X-ray diffraction, dispersive energy (EDS), scanning electron microscope (SEM), infrared as well as photoluminescence (PL) techniques were used to characterize obtained samples. Irregular and non-uniform structures were observed by SEM. EDS spectra confirmed the presence of Na, Cd, V, O and Sm elements in each sample. Uuder 405nm excitation, the NaCd1 − xVO4: xSm (x = 0.01, 0.03 and 0.05) exhibits a bright red emission consisting mainly of four wavelength peaks at 556, 593, 650 and 700 nm. The highest emission intensity was found with a composition of x = 0.05. The analysis of PL spectra suggest that studied samples can be used as a red emitting phosphors candidates for fabrication of white LEDs. The CIE chromaticity coordinates of prepared samples were close to the blue-emitting phosphors for NaCdVO4 and red-emitting ones for NaCd0.99Sm0.01VO4, NaCd0.97Sm0.03VO4, and NaCd0.95Sm0.05VO4. The band gap energies of phosphors were calculated from reflectance data using K-M function.

Photoluminescence and Crystal-Field Analysis of Pr3+-Doped SrMoO4 Phosphors

2015 ◽  
Vol 70 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Wenlin Feng ◽  
Huaping Lin ◽  
Honggang Liu
Keyword(s):  
Crystal Field ◽  
Charge Transfer Band ◽  
Hamiltonian Operator ◽  
Field Analysis ◽  
Energy Matrix ◽  
X Ray Diffraction ◽  
Strong Electron ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
Fluorescence Spectrometer

AbstractThe phosphor SrMoO4:Pr3+ was successfully prepared by high-temperature solid-state reaction process, and characterised by X-ray diffraction (XRD), scanning electron microscope (SEM), and fluorescence spectrometer. The results show that the prepared SrMoO4:Pr3+ has a scheelite structure with pure phase and represents leaf-like shapes with good dispersity. The strong electron absorbabilities are located at 220–300 nm (charge transfer band), 448, 474, and 487 nm, respectively. The emission spectrum of the SrMoO4:Pr3+ phosphor was characterised, which peaked at 529, 545, 554, 600, 619, and 645 nm, corresponding to the f–f transitions of Pr3+. The average International Commission on Illumination (CIE) chromaticity coordinates of the phosphors are x≈0.455, and y≈0.520, and the optimum doping mole fraction of Pr3+ is 0.2 mol.%. To better understand the fluorescent behavior of as-prepared phosphors, a complete 91×91 energy matrix was built by an effective Hamiltonian operator, including free ion and crystal-field interactions. The fluorescent spectra of Pr3+ ion at the tetragonal (S4) Sr2+ site of SrMoO4 crystal were firstly calculated from a full diagonalisation (of energy matrix) method. The fitting values are in good agreement with the experimental data.

Molecular tapes in the structure of isoguaninium chloride

2017 ◽  
Vol 74 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Urszula Anna Budniak ◽  
Paulina Maria Dominiak
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Charge Density ◽  
Interaction Energy ◽  
Electrostatic Interaction ◽  
Electrostatic Interactions ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure

Isoguanine, an analogue of guanine, is of intrinsic interest as a noncanonical nucleobase. The crystal structure of isoguaninium chloride (systematic name: 6-amino-2-oxo-1H,7H-purin-3-ium chloride), C5H6N5O+·Cl−, has been determined by single-crystal X-ray diffraction. Structure analysis was supported by electrostatic interaction energy (E es) calculations based on charge density reconstructed with the UBDB databank. In the structure, two kinds of molecular tapes are observed, one parallel to (010) and the other parallel to (50\overline{4}). The tapes are formed by dimers of isoguaninium cations interacting with chloride anions. E es analysis indicates that cations in one kind of tape are oriented so as to minimize repulsive electrostatic interactions.

Impact of various reactant concentrations on the morphology and photoluminescence property of synthetic ZnO nanobelts

2017 ◽  
Vol 31 (35) ◽  
pp. 1750337
Author(s):  
Guoxuan Qin ◽  
Yanan Wang ◽  
Shentong Mo ◽  
Xing Fu ◽  
Hui Wang ◽  
...  
Keyword(s):  
Photoluminescence Property ◽  
Xrd Analysis ◽  
Maximum Temperature ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices ◽  
Uv Emission ◽  
Zno Nanomaterials ◽  
Fluorescence Spectrometer

In this paper, ZnO nanobelts have been partially high-quality synthesized employing diverse reactant mass ratios between zinc acetate [Zn(AC)2] and polyvinyl alcohol (PVA) without any catalyst. The maximum temperature required for the whole reaction process is no more than 650[Formula: see text]C. The morphologies of ZnO nanomaterials fabricated from distinct reactant concentrations have been systematically investigated by means of field-emission scanning electron microscopy (FESEM). X-ray diffraction (XRD) analysis identifies that ZnO nanobelts exhibit a typical wurtzite structure. Through fluorescence spectrometer, the photoluminescence (PL) spectra generated by ZnO nanomaterials corresponding to different reactant concentrations have disparate peak intensities and luminescence wavelengths. This phenomenon indicates that novel-synthesized ZnO nanomaterial shows great potential in changing the optical properties of light-emitting devices. In addition, synthetic ZnO nanobelts exhibit excellent UV emission capability.

A Novel Technique of Flyash Utilization: Preparation of Silica from Flyash by Alkali Leaching

2010 ◽  
Vol 434-435 ◽  
pp. 814-815
Author(s):  
An Ran Guo ◽  
Jia Chen Liu ◽  
Yi Bing Sun ◽  
Wen Jun Lian ◽  
Lu Yang
Keyword(s):  
High Purity ◽  
Sodium Hydroxide Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Technique ◽  
Reinforcing Agent ◽  
Alkali Leaching ◽  
A New Technique ◽  
Fluorescence Spectrometer ◽  
Scanning Electron

A new technique of flyash utilization was presented and high-purity silica was prepared by alkali leaching. The flyash was added into sodium hydroxide solution, and then the suspension was heated to 115 °C for 30 min. After filtrated, the filtrate was collected and carbon dioxide was imported into the solution. Finally, the silica would precipitate from the solution. The silica was characterized by scanning electron microscopy, X-ray diffraction and X-ray fluorescence spectrometer. The high-purity silica prepared from flyash was qualified for the rubber reinforcing agent used in shoemaking.

scholarly journals Preparation of Nanoparticles Including Antisolvent Drugs by the Combination of Roll Milling and High-pressure Homogenization

2018 ◽  
Vol 14 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Seitaro Kamiya ◽  
Maya Yamada ◽  
Miki Washino ◽  
Kenichiro Nakashima
Keyword(s):  
Particle Size ◽  
High Pressure ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Peak Shift ◽  
Diffraction Peak ◽  
High Pressure Homogenization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Process

Description: Design methods of nanoparticle formulations are divided into break-down methods and build-up methods. The former is further divided into dry and wet processes. For drug nanoparticle preparations, the wet process is generally employed, and organic solvents are used in most formulations. Method: In this study, we investigate the preparation of nifedipine (IB) and griseofulvin (GF) nanoparticles without using organic solvent. Both IB and GF nanoparticles, with a mean particle size of approximately 50 nm, were prepared without organic solvent by employing a combination of roll milling and high-pressure homogenization. Result: The X-ray diffraction peak of the IB and GF samples prepared by roll milling was present at a position (2θ) identical to that of IB and GF crystals, indicating that no peak shift was induced by interaction with phospholipids. Conclusion: These findings demonstrate that most IB and GF nanoparticles exist as crystals in phospholipids.

Synthesis and Up-Conversion Luminescent Properties of Na(Y1.5Na0.5)F6 Hexagonal Prism

2016 ◽  
Vol 697 ◽  
pp. 318-321
Author(s):  
Cui Ping Zhong ◽  
Jie Jun Zhang ◽  
Shu Wang Duo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chelating Agent ◽  
Luminescent Properties ◽  
Hexagonal Prism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Near Ultraviolet ◽  
Fluorescence Spectrometer ◽  
Scanning Electron

Na (Y1.5Na0.5)F6 microparticks were prepared by hydrothermal method. EDTA as the chelating agent. The samples were characterized by X-ray diffraction, scanning electron microscopy and fluorescence spectrometer. The X-ray diffraction indicates that the crystal shows a hexagon phase structure. Under the excitation of 980nm laser, the Na (Y1.5Na0.5)F6 exhibited strong up-conversion light: 4F9/2→4I15/2(red), 4H11/2/4S3/2→4I15/2(green) and 4G11/2→2H9/2 (near-ultraviolet).

scholarly journals Surface Modification of LiMn2O4for Lithium Batteries by Nanostructured LiFePO4Phosphate

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
B. Sadeghi ◽  
R. Sarraf-Mamoory ◽  
H. R. Shahverdi
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Transmission Electron ◽  
Coating Method ◽  
Dip Coating Method ◽  
Spinel Cathode

LiMn2O4spinel cathode materials have been successfully synthesized by solid-state reaction. Surface of these particles was modified by nanostructured LiFePO4via sol gel dip coating method. Synthesized products were characterized by thermally analyzed thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The results of electrochemical tests showed that the charge/discharge capacities improved and charge retention of battery enhanced. This improved electrochemical performance is caused by LiFePO4phosphate layer on surfaces of LiMn2O4cathode particles.

Novel Red-Orange Phosphors Na2BaMg(PO4)2:Pr3+: Synthesis, Crystal Structure and Photoluminescence Performance

2018 ◽  
Vol 73 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Lu Pan ◽  
Xiaozhan Yang ◽  
Chaoyue Xiong ◽  
Dashen Deng ◽  
Chunlin Qin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Solid State Lighting ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Hexagonal Cell ◽  
X Ray ◽  
Trigonal System ◽  
Chromaticity Coordinates

AbstractA series of new red-orange emission phosphors Na2BaMg(PO4)2:Pr3+ were synthesised by a high-temperature solid-state reaction. The crystal structure and photoluminescence properties of these samples were characterised by X-ray diffraction and spectroscopic measurements. This compound holds P3̅m1 space group of the trigonal system with the lattice parameters of hexagonal cell a=0.5304(3) nm and c=0.6989(3) nm. The phosphor emits the strongest peak at 606 nm when excited by 449 nm. The average Commission Internationale de l’Eclairage chromaticity coordinates calculated for the phosphors are (0.52, 0.46). The results demonstrate the potential application of these phosphors in solid-state lighting and other fields.

Biosynthesis of silver nanoparticles using lavender leaf and their applications for catalytic, sensing, and antioxidant activities

2016 ◽  
Vol 5 (6) ◽  
Author(s):  
Brajesh Kumar ◽  
Kumari Smita ◽  
Luis Cumbal
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Antioxidant Activities ◽  
Present Report ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Red Color ◽  
Uv Visible

AbstractThe present report summarizes an eco-friendly approach for the biosynthesis of silver nanoparticles (AgNPs) using the leaf extract of lavender. Initially, the synthesis of AgNPs was visually observed by the appearance of a wine red color. The optical property, morphology, and structure of as-synthesized AgNPs were characterized by UV-visible spectroscopy, dynamic light scattering, transmission electron microscopy, and X-ray diffraction analyses. All characterization data revealed the formation of crystalline and spherical AgNPs (Ag/Ag

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