scholarly journals Spectral and Thermal Degradation of Melamine Cyanurate

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. Sangeetha ◽  
N. Kanagathara ◽  
R. Sumathi ◽  
N. Sivakumar ◽  
G. Anbalagan

Melamine cyanurate, an organic crystalline complex was, synthesized by evaporation of an aqueous solution containing equimolar quantities of melamine and cyanuric acid. The synthesized compound has been subjected to various characterizations like Powder XRD, FT-IR, TG-DTG, SEM, and SHG. The presence of sharp diffraction peaks in the XRD confirms that the products are highly crystalline. The average particle size was calculated using the Debye-Scherrer formula, and it was found to be 3.067 μm. Thermal behavior of the grown crystal has been studied by TG-DTG analysis. From TG-DTG, it is found that the title crystal possesses good thermal stability. The activation energy was calculated using the Broido, Coats-Redfern, and Horowitz-Metzger methods. A sharp peak exothermic peak at 405.40°C was assigned as the melting point of the title material. SEM reveals the morphology of the synthesized salt. No detectable signal was observed during the Kurtz-Perry technique.

2010 ◽  
Vol 7 (s1) ◽  
pp. S137-S142 ◽  
Author(s):  
M. Kayalvizhi ◽  
L. John Berchmans

Lithium nickelate and its lanthanum substituted compound have been successfully prepared by combustion synthesis process using LiNO3, Ni(NO3)2.6H2O and La(NO3)3.6H2O. Hexamine is used as fuel. The physicochemical properties of the powders were investigated by thermal analysis (TGA/DTA). The crystalline powders were characterized for their phase identification using x-ray diffraction analysis (XRD). FT-IR spectroscopy was used to study the local structure of the oxide environment. The morphological features of the powders were characterized by scanning electron microscopy (SEM). DTA analysis reveals the evolution of an exothermic peak at 465oC indicating the rapid decomposition of the hexamine and dissociation of nitrate salts, forming the final compound lithium nickealte. The XRD pattern reveals the rhombohedral structure of LiNiO2with trigonal symmetry comprising of two interpenetrating close packed FCC sub-lattices. The lattice constant values ̒a̓ and ̒c̓ are in good agreement with the reported data. In the FT-IR spectra, vibrational bands are identified in the range of 400-800 cm-1representing the NiO2layer. LiNiO2exhibits a very fine crystalline structure with an irregular morphology. The La substituted LiNiO2powder has shown a smooth-edged polyhedral structure with an average particle size of 5-10 μm.


2014 ◽  
Vol 606 ◽  
pp. 3-7
Author(s):  
Lee Siang Chuah ◽  
S.Y. Chin ◽  
S.S. Tneh ◽  
M.A. Ahmad ◽  
S.K. Mohd Bakhori ◽  
...  

ZnO nanosheetlike structures were synthesized on zinc (Zn) foil substrates by electrochemical deposition method in ZnCl2aqueous solutions at a temperature of 90 °C. In addition, the synthetic parameters in this work allow additional structural direction for ZnO nanoscaled structures. The morphology growth from smooth plane structures to nanosheet like structures could be accomplished by modifying the current densities of electrodeposition. In the photoluminescence (PL) spectra of the as-synthesized ZnO samples, typically there are few oxygen vacancies or interstitial Zn centers would be produced when the electrochemical deposition was performed out with a low current density. The UV peak is usually considered as the characteristic emission of ZnO nanosheetlike structures and attributed to the band edge emission or the exciton transition. All XRD diffraction peaks of ZnO nanosheetlike structures are shown in a good agreement with hexagonal structure. The average particle size was calculated using the Debye-Scherrer formula. ZnO nanosheetlike structures processed for various current densities have different size.


2015 ◽  
Vol 33 (1) ◽  
pp. 205-212 ◽  
Author(s):  
N. Srinivasan ◽  
J.C. Kannan

AbstractPure and aluminum doped zinc oxide nanoparticles were prepared by soft chemical method. The prepared nanoparticles were characterized by XRD, SEM-EDAX, UV-Vis, PL and FT-IR studies. XRD patterns revealed that the nanoparticles were crystallized in hexagonal wurtzite structure with an average particle size of 19 nm to 26 nm. The surface morphology was explored using SEM micrographs. The incorporation of aluminum was confirmed by EDAX and FT-IR studies. The band gaps of the particles were found from 3.48 eV to 3.53 eV through UV-Vis spectral studies. The defect related mechanism was investigated using PL measurements. The chemical functional groups in FT-IR spectra proved the formation of pure and aluminum doped zinc oxide nanoparticles.


2018 ◽  
Vol 382 ◽  
pp. 352-356 ◽  
Author(s):  
Supitcha Rungrodnimitchai ◽  
Sirinapa Mayod ◽  
Sutamma Tanasarn

In this study, ground tire rubber (R-GTR) with the average particle size of 456 µm was chemically modified to produce modified ground tire rubber (M-GTR) that can work as ion exchange materials. The modification was performed by oxidation reaction. The ground tire rubber was oxidized at the range of temperature from 20 to 40๐C for 48, 72 and 96 hours by a mixture of the HNO3/H3PO4/NaNO2system. The HNO3/H3PO4ratio was 1:3 and the concentration of NaNO2was 1.4% w/v. FT-IR revealed that the carboxyl group or the carbonyl group was successfully introduced into the modified ground tire rubber and SEM images demonstrated that the porosity of modified ground tire rubber increased. The results of the modified ground tire rubber showed that the carboxyl content increased with an increase of reaction time while %yield decreased with an increase of reaction time. The optimum condition for modification was the reaction at 30๐C for 96 hours.


2019 ◽  
Vol 11 (11) ◽  
pp. 1064-1070 ◽  
Author(s):  
Nkosinathi G. Dlamini ◽  
Albertus K. Basson ◽  
V. S. R. Rajasekhar Pullabhotla

Bioflocculant from Alcaligenis faecalis HCB2 was used in the eco-friendly synthesis of the copper nanoparticles. Nanoparticles were characterized using a scanning electron microscope (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, thermo gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). The transmission electron microscopy images showed close to spherical shapes with an average particle size of ∼53 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of the Cu nanopartilces and also the other elements such as O, C, P, Ca, Cl, Na, K, Mg, and S originated from the bioflocculant. FT-IR results showed the presence of the –OH and –NH2 groups, aliphatic bonds, amide and Cu–O bonds. Powder X-ray diffraction peaks confirmed the presence of (111) and (220) planes of fcc structure at 2 of 33° and 47° respectively with no other impurity peaks.


Author(s):  
Sorna Gowri Vijaya Kumar ◽  
◽  
Priyanka Prabhakar ◽  
Raj Kumar Sen ◽  
Neha Uppal ◽  
...  

Nanoflower is anticipated to become a very smart material due to its unique properties such as high surface to volume ratio. A hydrothermal method was used in this study to prepare the zinc oxide (ZnO) nanoflower and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The average particle size of the ZnO nanoflower was calculated as 21nm according to the Debye-Scherrer formula. The SEM result gives the surface morphological information of the ZnO nanoflower, which confirms the formation of the ZnO nanoflower. The ZnO nanoflower was dispersed in PDMS and coated onto cotton fabric to get the superhydrophobic fabric. The hydrophobicity was determined by measuring the water contact angle by the Sessile drop method and it was observed that coated fabrics have the highest contact angle, 140⁰ at 0.5% ZnO nanoflower concentration. The present study offers a method of fabrication of superhydrophobic cotton textile using ZnO nanoflower/PDMS polymer nanocomposites.


2021 ◽  
Vol 8 (3) ◽  
pp. 168-171
Author(s):  
Kurnia Kurnia ◽  
Meidy Kaseside ◽  
Steven Iwamony

Fe3O4 encapsulated PEG form iron sand at wari ino beach has been successfully synthesized by co-precipitation method. The average particle size  of the nanoparticle 11,3 nm was determined by scherrer formula. Fe3O4 modification PEG 4000 was successfully encapsulated the samples  by the presence C-O-C and CH bonding that were characterized using Fourier Transform Infra Red (FTIR), X-Ray Diffraction (XRD) pattern  shows that all samples  are formed by single  phase cubic spinel magnetite  , and Scanning Electron Microscopy (SEM) shows the  high dispersion capability while encapsulated process using  PEG. The results of the characterization show that the Fe3O4 successfully encapsulated by PEG 4000.


2021 ◽  
Vol 37 (2) ◽  
pp. 405-412
Author(s):  
Mohamed Habib Oueslati ◽  
Lotfi Ben Tahar ◽  
A. Khuzaim Alzahrani ◽  
Jamith Basha ◽  
Omar H. Abd Elkader

The present work reports a green biosynthesis of gold nano particles (EO-AuNPs) using an essential oil (EO) as a reducing agent of the Au(III) in HAuCl4. The EO was extracted by hydro-distillation from Diplotaxis acris flowers. A total of 16 compounds were detected from the EO oil by using GC–MS and 5-methylsulfanylpentanenitrile was identified as the major component (73.60 %). The biosynthesized EO-AuNPs were characterized performing UV–Vis, IR,XRD and TEM analyses.The UV-Vis revealed the typical features of surface plasmon resonance (SPR) of AuNPs at ~526 nm. The FT-IR spectrum of the biosynthesized nano particles exhibited the features of the nitrile (-C≡N) functional group indicating that the -C≡N-bearing EO components are likely acting as reducing and stabilizing agents for the formation of EO-AuNPs. The plausible scheme of EO-AuNPsformation was proposed.The TEM analysis showed that the EO- AuNPs were almost spherical in shape with an average particle size of 12.7 nm. In addition, the antimicrobial activity was carried out by diffusion of agar wells method. The results proved that the EO-AuNPs displayed a potential antimicrobial against gram negative strains, with a maximum zone of inhibition of 16 mm for E. coli at a concentration of 100 µg / ml.


2020 ◽  
Vol 32 (9) ◽  
pp. 2130-2134
Author(s):  
B. VARUN KUMAR ◽  
Y. PARVEEN TAJ ◽  
K. HUSSAIN REDDY

Copper nanoparticles (CuNPs) have captivated amazing and renewable interest in recent years due to their fascinating features. In present investigation, CuNPs were produced by reducing copper sulphate with ascorbic acid (vitamin C) in aqueous medium without inert gas insulation at low temperature (80 ºC). In present synthetic procedure, a native vitamin C was applied as insulating agent to prevent oxidation of nascent CuNPs during the process and in storage. Triton X-100 was added that worked both as a size controller and as a capping agent. The CuNPs were characterized by UV-visible and FT-IR spectroscopies, powder X-ray diffraction (PXRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). Optical properties of Cu nanoparticles were explored using UV-vis spectroscopy. FT IR was employed to uncover the bonding between copper nanoparticles and Triton X-100. The CuNPs were discerned by PXRD and SEM-EDX Techniques. From the major diffraction peaks, the average particle size is determined using Debye-Scherer equation and it is found to be about 15 nm. It is hoped that the present results would pave a way for developing plans for the production of nascent CuNPs in the absence of inert gas insulation.


2011 ◽  
Vol 228-229 ◽  
pp. 639-644 ◽  
Author(s):  
Jian Lin Xu ◽  
Shu Hua Yang ◽  
Li Hui Zhang ◽  
Zhao Kang ◽  
Qiang Guo

The nano-antimony particles with different shape, size and stability are prepared by electrochemical method under the dilute hydrochloric acid electrolyte including the surface dispersant OP-10 and different current densities. The influences of current density on the shape and size of nanometer antimony particles prepared by electrochemical method are analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The results show that nano-antimony powder can be prepared by electrochemical method, and the antimony powder possesses the crystal structure with orthorhombic hexahedron. The current density has a significant impact on the agglomeration, shape and size of antimony powder. The size and shape of antimony powder are determined by the nucleation rate of nano-antimony and combination capacity of antimony ions and OP-10 surface dispersing agents affected by current density. When the current density is 25mA/cm2, the average particle size is 12nm or so, the shape is spherical, and the nano-antimony particles are well dispersed and no agglomeration.


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