scholarly journals Synthesis and Irreversible Thermochromic Sensor Applications of Manganese Violet

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1693 ◽  
Author(s):  
Duy Nguyen ◽  
Quang-Vu Bach ◽  
Jong-Han Lee ◽  
In-Tae Kim
Keyword(s):  
Color Change ◽  
Intermediate Phase ◽  
Silicate Solution ◽  
X Ray Diffraction ◽  
Direct Oxidation ◽  
X Ray ◽  
Sensor Applications ◽  
Violet Pigment ◽  
Thermochromic Material ◽  
Oxidation Of Ammonia

An irreversible thermochromic material based on manganese violet (MnNH4P2O7) is synthesized. The crystal phase, chemical composition, and morphology of the synthesized material are analyzed using X-ray diffraction, scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, and Fourier-transform infrared spectroscopy. The absorption spectra of the synthesized material are obtained using a UV-Vis spectrometer, and the thermochromism exhibited by the powdered samples at high temperatures is also investigated. The as-synthesized manganese violet pigment consists of pure α-MnNH4P2O7 phase. In addition, the synthesized pigment largely consists of hexagonal crystals with a diameter of hundreds of nanometers. On heating, the pigment simultaneously loses H2O and NH3 in two successive steps at approximately 330–434.4 °C and 434.4–527 °C, which correspond to the formation of an intermediate phase and of Mn2P4O12, respectively. An overall mass loss of 14.22% is observed, which is consistent with the expected 13.79%. An irreversible color change from violet to white is observed after exposure of the synthesized manganese violet pigment at 400 °C for 30 min. This is attributed to the oxidation of ammonia to hydroxylamine, which then decomposes to nitrogen and water, or alternatively to the direct oxidation of ammonia to nitrogen. Furthermore, we demonstrate the potential application of synthesized manganese violet in the production of irreversible thermochromic paint by mixing with potassium silicate solution as a binder and deionized water as a solvent at a specific ratio. The thermochromic paint is then applied in fabrication of irreversible thermochromic sensors by coating it onto a steel plate surface. Finally, we show that manganese violet-based irreversible thermochromic sensors are able to detect temperatures around 400 °C by changing color from violet to white/milky.

scholarly journals Electrical, structural, and photocatalytic properties of copper oxide nanowire

2020 ◽  
Vol 44 (7-8) ◽  
pp. 471-474
Author(s):  
Azadeh Jafari ◽  
SAA Terohid ◽  
Alireza Kokabi ◽  
Amir Moradiani
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Copper Oxide ◽  
Growth Temperature ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Direct Oxidation ◽  
Oxide Nanowires ◽  
X Ray ◽  
Scanning Electron

Using a direct oxidation method in a horizontal quartz tube, copper oxide nanowires are grown on a Cu substrate. In order to investigate the growth temperature effects on the structural, morphological, electrical, and photocatalytic properties of the copper oxide nanowires, X-ray diffraction, scanning electron microscopy, a KEITHLEY 2361 system, and a homemade photoreactor are used. The X-ray diffraction results show that both CuO and Cu2O phases are formed, and while increasing the growth temperature, the crystallinity is improved and the intensity of most of the diffraction peaks increases. The scanning electron microscopy images at different growth temperatures show that the number, density, and length of the copper oxide nanowires on pre-formed micro-scaled grains increase, when the growth temperature increases to 700°C and sharper nanowires with average diameters of 1–3 µm grow on the surface. Also I–V curves show that by raising the growth temperature, the conductivity of the samples increases. In addition, the photocatalytic activities are studied by photocatalytic degradation of Congo red dye, and based on these results, the sample grown at 700°C with the highest number and density of the nanowires showed the best photocatalytic performance and electrical conductivity. The results can be used to guide better understanding of the growth behavior of copper oxide nanowires and can be useful for the development of novel photocatalytic nanodevices.

scholarly journals Effect of Various Parameters on Bio-Synthesis of Copper Nanoparticles Using Citrus Medica Linn (Lemon) Extract and Its Antibacterial Activity

2020 ◽  
Vol 1 (1) ◽  
pp. 51-58
Author(s):  
Sharmila Pradhan ◽  
Rajeswori Shrestha ◽  
Khuma Bhandari
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Color Change ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Crystalline Nature ◽  
Bio Synthesis

This research is focused on bio-synthesis of Copper nanoparticles (CuNPs) using lemon extract to study the effect of various parameters on synthesis and to explore antibacterial activity. The biomolecules present in lemon extract act as self reducing and stabilizing agent. The synthesis of CuNPs was found to be affected by various parameters like volume of the lemon extract, concentration of the precursor and the temperature etc. Preliminary characterization of formation of nanoparticles were done by color change and UV-visible (UV-vis) spectroscopy. Elemental composition of the prepared sample was determined via Energy Dispersive X-ray (EDX) Spectroscopy. Presence of important functional groups associated with biomolecules is well characterized by Fourier Transform Infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM ) revealed the formation agglomerated CuNPs of different shape and sizes and the X-ray diffraction pattern showed the formation of purely crystalline nature of CuNPs. Finally, agar well diffusion method showed that CuNPs have potential antibacterial activity against Gram-ve bacteria compared to Gram +ve bacteria.

Studies on the reaction between strontium carbonate and iron(III) oxide

1971 ◽  
Vol 24 (2) ◽  
pp. 237 ◽  
Author(s):  
J Beretka ◽  
T Brown
Keyword(s):  
Carbon Dioxide ◽  
Low Temperatures ◽  
Intermediate Phase ◽  
Strontium Carbonate ◽  
Direct Reaction ◽  
X Ray Diffraction ◽  
X Ray

The reaction between strontium carbonate and iron(III) oxide has been studied in a system open to the atmosphere and in a vacuum. The extent of reaction was calculated from the analysis of the solid products by X-ray diffraction and, in the case of the experiments in vacuum, from the amount of carbon dioxide evolved from the system also. ��� In vacuum, the monoferrite SrFe2O4 results from the direct reaction of strontium carbonate and iron(III) oxide at comparatively low temperatures, while the hexaferrite SrFe12O19 is formed by the reaction of Sr2Fe2O4 with iron(III) oxide at higher temperatures. The formation of the ferrite Sr2Fe2O5 depends upon the prevailing atmosphere, since this compound was present only as an intermediate phase when the experiments were carried out in air and not in vacuum. Only three compounds of strontium, iron, and oxygen were found, namely the ferrites SrFe2O4, Sr2Fe2O5, and SrFe12O19. ��� The observataions appear to be explicable in terms of Tammann temperatures.

Hydroxyapatite Precursor Phases Identification by X-Ray Diffraction Using Synchrotron Radiation

2007 ◽  
Vol 330-332 ◽  
pp. 115-118 ◽  
Author(s):  
Silvia R. A. Santos ◽  
Antonella M. Rossi ◽  
Marcelo Henrique Prado da Silva
Keyword(s):  
Synchrotron Radiation ◽  
Diffraction Analysis ◽  
Intermediate Phase ◽  
Octacalcium Phosphate ◽  
Alkali Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Intensity ◽  
Synchrotron Light ◽  
Precursor Phases

The present study presents the relevance of X-ray diffraction analysis using synchrotron light in the identification of phases with low intensity peaks. Niobium sheets were coated with monetite and then converted to hydroxyapatite in an alkali solution. Octacalcium phosphate was identified as an intermediate phase in the conversion monetite-hydroxyapatite.

Reaction Mechanism of LiFePO4/C Cathode Materials Synthesized by Carbothermal Reduction Method

2010 ◽  
Vol 178 ◽  
pp. 248-253 ◽  
Author(s):  
Li Min Gao ◽  
Guang Chuan Liang ◽  
Li Wang ◽  
Xiao Ke Zhi ◽  
Xiao Fei Jie
Keyword(s):  
Carbothermal Reduction ◽  
Reduction Method ◽  
Intermediate Phase ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Reducing Atmosphere ◽  
Carbothermal Reduction Method ◽  
Lower Temperature

LiFePO4/C powders were synthesized by carbothermal reduction method using Li2CO3 (A.R), FePO4 (A.R) and glucose as raw materials. In this paper, the carbothermal reaction courses were characterized by Thermo-gravimetric (TG)/Differential Thermal Analysis (DTA), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). It was found that the different synthesis temperatures and the different reducing atmosphere in systems could lead to different reactions, resulting in different final products and a direct impact on material performance. At around 350 °C LiFePO4 is directly formed without intermediate phase. In lower temperature of 400-500 °C, the sample included a certain amount of Li3PO4 and Fe2O3 impurity phases. When calcination temperature rose to 550 °C, the sample could be pure LiFePO4 phase.

scholarly journals X-ray diffraction and SEM/EDX studies on technological evolution of the oxide-fluoride ceramic flux for submerged arc-surfacing

2012 ◽  
Vol 48 (1) ◽  
pp. 101-113 ◽  
Author(s):  
V.E. Sokolsky ◽  
A.S. Roik ◽  
A.V. Davidenko ◽  
V.P. Kazimirov ◽  
V.V. Lisnyak ◽  
...  
Keyword(s):  
Thermal Evolution ◽  
Silicate Solution ◽  
Component Composition ◽  
X Rays ◽  
X Ray Diffraction ◽  
Intensity Pattern ◽  
X Ray ◽  
Ceramic Flux ◽  
Main Component ◽  
Submerged Arc

The ceramic flux for submerged arc-surfacing with main component composition MgO (10.0 wt. %)-Al2O3 (25.0 wt. %)-SiO2 (40.0 wt. %)-CaF2 (25.0 wt. %) was prepared in a disk dryer-granulator using a sodium/potassium silicate solution as a binder. X-ray powder diffraction (XRPD) collected at r.t. identified ?- phase of quartz, Al2O3, MgO and CaF2 of the initial components in the samples taken after granulation and subsequent annealing at 600 ?C. In contrast to the low temperature annealing, anorthite (CaAl2Si2O8) is the main phase in the composition of the samples remelted at 1500 ?C and quenched subsequently. Chemical analysis performed by means of scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis (SEM/EDX) detects that the grains of the remelted samples possess the same Ca : Al : Si elemental ratio as anorthite. High temperature X-ray diffraction (HTXRD) was used to examine structural transformation in the solid at 600 ?C < T < 1200 ?C and stages of thermal evolution of ceramic flux were determined. The ceramic flux melts completely at the temperature above 1350 ?C. The intensity pattern of the flux melt was obtained by X-ray diffraction of scattered X-rays at 1450 ?C. After calculating the structure factor (SF), the radial distribution function (RDF) was evaluated and used to calculate the structural basicity of the flux melt.

scholarly journals Green Approach for Synthesis of Manganese Nanoparticle using Banana Peel (Musa paradiasca) and its Characterization

2021 ◽  
Vol 2 (01) ◽  
pp. 75-82
Author(s):  
Sharmila Pradhan Amatya ◽  
Santu Shrestha ◽  
Yadav Aryal
Keyword(s):  
Color Change ◽  
Precursor Solution ◽  
Banana Peel ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Green Approach ◽  
Ft Ir ◽  
Crystalline Nature ◽  
Peel Extract

This research mainly aims at implementing green approach for synthesizing multifunctional manganese nanoparticles (MnNPs) using aqueous extract of banana peel (Musa paradiasca) and potassium permanganate (KMnO4) as the precursor. As synthesized MnNPs were confirmed initially by a color change and later on characterized by UV-visible (UV-vis) Spectrophotometer, Energy Dispersive Spectroscopy (EDX), X-ray Diffraction Spectroscopy (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Green approach was carried at various parameters like concentration of precursor solution, reaction time, temperature, etc for optimization. The formation of MnNPs was confirmed by the presence of surface plasmon absorbance band  (450 nm) and band at 6 and 6.5 keV of EDX spectrum. Likewise, so formed MnNPs were crystalline nature depicted from the sharp peak observed at 28.5º and 41° in X-ray diffraction pattern. Various types of biomolecules associated with the banana peel extract acting as natural reducer and stabilizer were analyzed from characteristic absorption bands present in the FT-IR spectrum.

Humidity properties of Schiff base polymers

2018 ◽  
Vol 16 (1) ◽  
pp. 937-943
Author(s):  
Ramazan Demir ◽  
Ismet Kaya
Keyword(s):  
Schiff Base ◽  
Quartz Crystal ◽  
X Ray Diffraction ◽  
Sensing Element ◽  
Water Steam ◽  
X Ray ◽  
Moisture Sensor ◽  
Sensor Applications ◽  
Response Characteristics ◽  
Schiff Base Polymers

AbstractThe synthesized Schiff base polymers were investigated for humidity and chloroform response characteristics. The crystal structure of polymers were analyzed using X-ray diffraction (X-RD) method. We used the QCM (quartz crystal microbalance) method for the analyses of the water steam adsorption and desorption ratio of polymers. The experimental results showed that Schiff base polymers were very sensitive to humidity and chloroform at room temperature and it was possible to use it as a sensing element in moisture sensor applications.

AN INTERLOCKING SINGLE-STRAND MODEL FOR FIBRIN POLYMERIZATION.

1987 ◽  
Author(s):  
E B Hunziker ◽  
P W Straub ◽  
A Haeberli
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Binding Sites ◽  
Intermediate Phase ◽  
Single Strand ◽  
Negative Staining ◽  
X Ray Diffraction ◽  
Fibrin Polymerization ◽  
X Ray ◽  
Polypeptide Chains

The early stages of fibrin polymerization were investigated by rotatory shadowing and electron microscopy. Individual molecules within initial oligomers were found to be unaligned and contacted neighbouring molecules by single E + D and D + E contacts, suggesting an intermediate phase of activation (des A-fibrin). The interacting molecular domains were separated by a distance of 2 to 3 nm, indicating that (both or at least one) binding sites are located on protruding segments of the polypeptide chains. Upon completion of fibrin activation (des AA-fibrin), molecules within the early oligomers aligned to form single-stranded polymers,o these being characterized by repeating trinodular units of 230 A in length. Based upon these findings, a new interlocking single-stranded model for fibrin polymerization was designed and tested. The model is consistent with previous experimental data on fibrin polymerization such as that obtained by X-ray diffraction and negative staining. Moreover, early branching and lateral association phenomena are easily explained.

Synthesis of Environment Friendly Manganese Doped Metal Oxide Nanoparticles for the Bio sensor Applications

2021 ◽  
Vol 10 (3) ◽  
pp. 09-15
Author(s):  
Priyadharshini Muthukumaravel ◽  
Rajesh Pattulingam ◽  
Syed Illiyas Syed Maqbool ◽  
Hariharan Venkatesan ◽  
Ezhil Inban Manimaran
Keyword(s):  
Phase Formation ◽  
Metal Oxide Nanoparticles ◽  
Secondary Phase ◽  
Spectroscopic Studies ◽  
Band Gap Energy ◽  
Fe2o3 Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensor Applications ◽  
Uv Visible

The present work focuses the synthesis of Manganese(Mn) doped Fe2O3 nanoparticles via an environmental friendly method which find their suitability for biosensors applications using the extraction of Nyctanthes arbor tristis seed for the first time. The synthesized Mn (~2, 3 & 5 wt. %) doped Fe2O3 were characterized by Powder X-ray diffraction (XRD), Field emission Scanning electron microscopy (FE-SEM), Cyclic voltammeter, Infrared and UV visible spectroscopic studies. The powder X-ray diffraction analysis exposed the phase formation and α - Fe2O3 nanoparticles in the case of annealed sample. Also, interesting secondary phase formation observed in the case of Mn 5wt. % doped samples. The optical properties of Mn (~2, 3 & 5 wt. %) doped Fe2O3 samples was determined by utilizing UV – Visible spectroscopic technique and the corresponding band gap energy was found to be 5.83 eV. The chemical bonds as well as functional groups in the compound were confirmed by the analysis of FT-IR spectrum. The morphology of the prepared samples were observed at micro level using FE-SEM analysis.Cyclic voltammeter was used to find the suitability of the prepared samples for proposed bio sensor applications.  

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