scholarly journals The influence of short thermal treatment on structure, morphology and optical properties of Er and Pr doped ceria pigments: Comparative study

2019 ◽  
Vol 13 (3) ◽  
pp. 310-321 ◽  
Author(s):  
Dragana Micovic ◽  
Maja Pagnacco ◽  
Predrag Bankovic ◽  
Jelena Maletaskic ◽  
Branko Matovic ◽  
...  
Keyword(s):  
Optical Properties ◽  
Single Phase ◽  
Temperature Treatment ◽  
Sem Analysis ◽  
Colour Properties ◽  
Colorimetric Analysis ◽  
Structural Behaviour ◽  
Structure Morphology ◽  
Red Ceramic Pigments ◽  
Thermal Stability Of

Potential non-toxic pink and red ceramic pigments based on CeO2 were successfully synthesized by selfpropagating room temperaturemethod and thermally treated at 600, 900 and 1200?C for 15min. The structure, morphology and optical properties, as well as thermal stability of Ce1-xErxO2-? and Ce1-xPrxO2-?(x = 0.05) were examined. Single-phase composition of all obtained CeO2 pigments was confirmed using XRPD method and Raman spectroscopy and it was not dependent on temperature. The mechanism of structural behaviour was thoroughly examined using Raman and FTIR spectroscopy. Nanometric dimensions of the crystallites of all pigments were confirmed using XRPD, TEM and FE-SEM analysis. Colour properties were dependent on the temperature treatment, and their position in the chromaticity diagram was studied using UV/VIS spectrophotometry. Colour efficiency measurements were supplemented by colorimetric analysis. It is proved that all samples are thermally stable in the investigated temperature range (up to 1200?C), and their potential application as environmentally friendly pigments of desired colour is confirmed.

The Influence of ZnO Sintering Aid on Properties of BaZr1-xYxO3-δ Proton-Conducting Electrolyte

2013 ◽  
Vol 591 ◽  
pp. 249-252
Author(s):  
Cheng Peng ◽  
Yi Xiong Zheng
Keyword(s):  
Single Phase ◽  
Lattice Parameter ◽  
Sem Analysis ◽  
Impedance Spectra ◽  
Sintering Aid ◽  
Proton Conducting ◽  
Structure Morphology ◽  
Different Temperatures ◽  
Electrode Interface ◽  
Increasing Temperature

The influence of ZnO sintering aid on the structure, morphology and electrical properties of BaZr1-xYxO3-δ proton-conducting electrolyte is presented. XRD showed that all the samples mainly consisted of single-phase cubic perovskite structure. Except for BaZrO3+ 1wt% ZnO, other samples show a peak arising from a small amount of Y2O3 impurity. SEM analysis showed that all the materials have a very dense structure after being sintered at 1300 oC with ZnO sintering aid. For densified BaZr1-xYxO3-δ+ 1wt% ZnO system the ZnO addition did not lead to increase the grain size. The change of the crystal structure of BaZr1-xYxO3-δ + 1wt% ZnO system with the content of doped yttrium was investigated. The lattice parameter and unit cell volume increased sharply at x<0.2, but it was maximal and almost constant at x≥0.2. The impedance spectra for BaZr0.8Y0.2O3-δ + 1wt% ZnO sample at three different temperatures were compared. With increasing temperature the resistance for mass transfer at the electrolyte-electrode interface was reduced markedly compared to that of the grain boundary.

scholarly journals Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  
Keyword(s):  
Food Packaging ◽  
Thermo Gravimetric Analysis ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Total Phenolic ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Phenolic And Flavonoid ◽  
Thermal Stability Of

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

Control of crystal structure, morphology and optical properties of ceria films by post deposition annealing treatments

2016 ◽  
Vol 603 ◽  
pp. 363-370 ◽  
Author(s):  
Asmaa Eltayeb ◽  
Rajani K. Vijayaraghavan ◽  
Anthony P. McCoy ◽  
Joseph Cullen ◽  
Stephen Daniels ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Post Deposition Annealing ◽  
Structure Morphology ◽  
Post Deposition

On the effects of thermal treatment on the composition, structure, morphology, and optical properties of hydrogenated amorphous silicon-oxycarbide

2009 ◽  
Vol 24 (8) ◽  
pp. 2561-2573 ◽  
Author(s):  
Spyros Gallis ◽  
Vasileios Nikas ◽  
Eric Eisenbraun ◽  
Mengbing Huang ◽  
Alain E. Kaloyeros
Keyword(s):  
Optical Properties ◽  
Thermal Treatment ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Effective Cross Section ◽  
Silicon Oxycarbide ◽  
Nuclear Reaction Analysis ◽  
Structure Morphology ◽  
Composition Structure ◽  
Hydrogenated Amorphous

The composition, structure, morphology, and optical characteristics of hydrogenated amorphous silicon-oxycarbide (a-SiCxOyHz) materials were investigated as a function of experimental processing conditions and post-deposition thermal treatment. Thermal chemical vapor deposition (TCVD) was applied to the growth of three different types of a-SiCxOyHz films, namely, SiC-like (SiC1.08O0.07H0.21), Si-C-O (SiC0.50O1.20H0.22), and SiO2-like (SiC0.20O1.70H0.24). The resulting films were subsequently annealed at temperatures ranging from 500 °C to 1100 °C for 1 h in an argon atmosphere. The composition, structure, and morphology of as-deposited and post-annealed films were characterized by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), nuclear-reaction analysis (NRA), and scanning electron microscopy. Corresponding optical properties were assessed by spectroscopic ultraviolet-visible ellipsometry (UV-VIS-SE). These studies led to the identification of an optimized process window for the growth of Er doped silicon oxycarbide (SiC0.5O1.0:Er) thin film with strong room-temperature photoluminescence emission measured around 1540 nm within a broad (460 nm to 600 nm) wavelength band. Associated modeling studies showed that the effective cross section for Er excitation in the SiC0.5O1.0:Er matrix was approximately four orders of magnitude larger than its analog for direct optical excitation of Er ions.

A study on structure, morphology, optical properties, and photocatalytic ability of SrTiO 3 /TiO 2 granular composites

2018 ◽  
Vol 532 ◽  
pp. 37-41 ◽  
Author(s):  
Le Thi Mai Oanh ◽  
Nguyen Xuan Huy ◽  
Doan Thi Thuy Phuong ◽  
Do Danh Bich ◽  
Nguyen Van Minh
Keyword(s):  
Optical Properties ◽  
Photocatalytic Ability ◽  
Structure Morphology ◽  
Granular Composites

Properties of Cubic Si3N4 Obtained by Shock Synthesis

2007 ◽  
Vol 566 ◽  
pp. 129-134 ◽  
Author(s):  
V.D. Blank ◽  
A.A. Deribas ◽  
N.A. Lvova ◽  
R.H. Bagramov ◽  
B.A. Kulnitsky ◽  
...  
Keyword(s):  
Heat Effect ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Structural Investigations ◽  
Equilibrium Pressure ◽  
High Pressure High Temperature ◽  
Using Data ◽  
T Phase ◽  
Thermal Stability Of ◽  
Complete Transformation

The cubic γ-Si3N4 phase was synthesized by the shock technique from the hexagonal β-Si3N4 phase. The thermal stability of the γ-Si3N4 was investigated during heating in vacuum up to 1773 K. An exothermal heat effect was found at 1690 K and structural investigations revealed complete transformation of γ-Si3N4 to β-Si3N4. Corresponding heat effect value was estimated as 51.3±7.7 KJ/mol. The high-pressure-high-temperature treatment (P=13 GPa, T=1300-2300 K) was applied to γ-Si3N4 to make bulk polycrystalline non-porous samples. It was found that temperatures below 1623 K do not change content of the cubic γ-Si3N4 while temperatures above 2273 K decrease it substantially. Mechanical properties of these bulk samples were measured by acoustic wave and nanoindentation techniques. The maximum values belong to cubic γ-Si3N4: hardness 39-44 GPa, Young’s modulus 475 Gpa and bulk modulus 263 GPa. Equilibrium γ-β line position in P-T phase diagram was estimated by using data obtained in this work. The equilibrium pressure at T=300 K was estimated as P300=7.0±2.0 GPa.

Medium-term thermal stability of amorphous Ge2Sb2Te5 flash-evaporated thin films with regards to change in structure and optical properties

2009 ◽  
Vol 517 (16) ◽  
pp. 4694-4697 ◽  
Author(s):  
T. Wagner ◽  
J. Orava ◽  
J. Prikryl ◽  
T. Kohoutek ◽  
M. Bartos ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Optical Properties ◽  
Medium Term ◽  
Thermal Stability Of

Preparation of Poly(aniline-co-phenol) and Study Its Properties and Its Polymerization Kinetics Using Two Methods: UV-Vis and HPLC

2021 ◽  
Vol 43 (5) ◽  
pp. 505-505
Author(s):  
Juhaina Alghdir and Ahmad Falah Juhaina Alghdir and Ahmad Falah
Keyword(s):  
Transition Temperature ◽  
Reaction Order ◽  
Sem Analysis ◽  
304 Stainless Steel ◽  
Melting Transition ◽  
Gravimetric Analysis ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Thermal Stability Of ◽  
Poly Aniline

The co-polymerization of polyaniline is one of the most important methods used to improve the electrical activity and thermal stability of polyaniline. Previously, electrochemical co-polymerization of phenol and aniline was performed on 304 stainless steel anodes. In this study, we present the co-polymerization of aniline and phenol chemically at laboratory temperature in an acidic medium with ammonium pyrosulfate as an oxidant. The Scanning Electron Microscopy (SEM) analysis of poly(aniline-co-phenol) sample shows a rough (non-smooth) surface with crystalline particles with microscopic diameters. We characterized the prepared polymer with DSC, DTA, and thermos gravimetric analysis (TGA). We found that the thermal decomposition of poly(aniline-co-phenol) was on six steps. The glass transition temperature of the co-polymer (Tg) was found at 863.89 and#176;C and the melting transition temperature was observed at 877.80 and#176;C. We studied the kinetics of Poly(aniline-co-phenol) using two methods: UV-Vis, HPLC. Then we determined the reaction order. It was found that the reaction was the zero-order reaction (n=0) in both previous two methods.

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