PAN Czytelnia Czasopism, Acetone adsorption on CO2-activated tyre pyrolysis char - Thermogravimetric analysis - Chemical and Process Engineering
Gai, Chao, Liu, Zhengang, Han, Guanghua, Peng, Nana, Fan, Aonan (2015). Combustion behavior and kinetics of low-lipid microalgae via thermogravimetric analysis. Bioresource Technology 181 : 148-154. [email protected] Repository. https://doi.org/10.1016/j.biortech.2015.01. ...
Highlights: • Volatiles, particularly proteins, play a key role in sludge combustion. • Sludge combustion performance varies with different sludge organic concentrations. • Carbohydrates significantly affect the combustion rate in the second stage. • Combustion performance of digested sludge is more negative compared with others. - Abstract: Wastewater treatment plants produce millions of tons of sewage sludge. Sewage sludge is recognized as a promising feedstock for power generation via combustion and can be used for energy crisis adaption. We aimed to investigate the quantitative effects of various sludge characteristics on the overall sludge combustion process performance. Different types of sewage sludge were derived from numerous wastewater treatment plants in Beijing for further thermogravimetric analysis. Thermogravimetric-differential thermogravimetric curves were used to compare the performance of the studied samples. Proximate analytical data, organic compositions, elementary ...
Biodiesel is a clean and renewable resource that consists of mono-alkyl esters of long chain fatty acid, which could be obtained from the transesterification reaction of vegetable oils and animal fats with alcohols and catalysts. Biodiesel yield has typically been determined using expensive and laborious techniques. The attempt of this study was to examine the potential of quantifying the biodiesel conversion in real time using refractive index in transesterification process of canola oil with methanol and KOH. Biodiesel yields at five different mixing intensities and reaction times were measured using a refractometer. The measured results were then compared with analytical data obtained from thermogravimetric analysis (TGA) technique over a temperature range of 25℃ - 600℃. Experimental results indicated that the FAME conversions at different mixing intensity and reaction time measured from refractometer correlated well to the relative weight losses from TGA method with R2 = 0.93 (p ≤ 0.05);
The composites of biodegradable poly(propylene carbonate) (PPC) reinforced with short Hildegardia populifolia natural fiber were prepared by melt mixing followed by compression molding. The mechanical properties, thermal properties, and morphologies of the composites were studied via static and dynamic mechanical measurements, thermogravimetric analysis, and scanning electron microscopy (SEM) techniques, respectively. Static tensile tests showed that the stiffness and tensile strength of the composites increased with an increasing fiber content. However, the elongation at break and the energy to break decreased dramatically with the addition of short fiber. The relationship between the experimental results and the compatibility or interaction between the PPC matrix and fiber was correlated. SEM observations indicated good interfacial contact between the short fiber and PPC matrix. Thermogravimetric analysis revealed that the introduction of short Hildegardia populifolia fiber led to a slightly ...
TGA can be used to evaluate the thermal stability of a material. In a desired temperature range, if a species is thermally stable, there will be no observed mass change. Negligible mass loss corresponds to little or no slope in the TGA trace. TGA also gives the upper use temperature of a material. Beyond this temperature the material will begin to degrade. TGA has a wide variety of applications, including analysis of ceramics and thermally stable polymers. Ceramics usually melt before they decompose as they are thermally stable over a large temperature range, thus TGA is mainly used to investigate the thermal stability of polymers. Most polymers melt or degrade before 200 °C. However, there is a class of thermally stable polymers that are able to withstand temperatures of at least 300 °C in air and 500 °C in inert gases without structural changes or strength loss, which can be analyzed by TGA.[6] For example, the polyimide Kapton® loses less than 10% mass when held in 400 °C air for 100 ...
ACKNOWLEDGMENTS. The authors are grateful for the Natural Science Foundation of Jiangsu Province (Grant No. BK20161524), the Doctorate Fellowship Foundation of Nanjing Forestry University (2015), the Jiangsu Province Ordinary University Students Scientific Research Innovation Project (KYZZ16_0319), the National Natural Science Foundation of China (Grant No. 31400515), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). Also, this paper was sponsored by the Qing Lan Project.. REFERENCES CITED. Abnisa, F., and Wan, A. (2015). "Optimization of fuel recovery through the stepwise co-pyrolysis of palm shell and scrap tire," Energy Conversion & Management 99, 334-345. DOI: 10.1016/j.enconman.2015.04.030. Abnisa, F., and Wan, M. (2014). "A review on co-pyrolysis of biomass: An optional technique to obtain a high-grade pyrolysis oil," Energy Conversion & Management 87, 71-85. DOI: 10.1016/j.enconman.2014.07.007. Brebu, M., Ucar, S., Vasile, C., and Yanik, J. ...
A new polymorphic form of ciprofloxacin saccharinate (CIP-SAC II) is presented, and compared with CIP-SAC I, a different polymorph which we had previously reported. The characterization techniques used were single crystal and powder X-ray diffraction, differential scanning calorimetry, thermogravimetry analysis and infrared and (13)C solid-state nuclear magnetic resonance spectroscopy. The results obtained from these techniques are consistent. Differential scanning calorimetry and thermogravimetric analysis showed that the reaction between the precursors is completed and the crystalline forms of both salts obtained (I and II) are highly pure. Infrared spectroscopy gave clear evidence of a salt formation. Solid-state nuclear magnetic resonance spectroscopy would indicate some degree of qualitative similarity in the intermolecular interaction scheme in both polymorphs, while thermal analysis data might indicate a difference in quantitative terms. A thorough single crystal structure determination ...
TY - JOUR. T1 - Thermal decomposition kinetics of polymeric wastes using a nonisothermal thermogravimetric method. AU - Kim, Yong Sang. AU - Kim, Young Seok. AU - Kim, Kwan Moon. AU - Jeong, Seong Uk. AU - Kim, Sung Hyun. PY - 2003. Y1 - 2003. N2 - Nonisothermal kinetic experiments of polymeric wastes, such as polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET), were studied in nitrogen atmosphere, and kinetic parameters were analyzed by Flynn-Wall method. The mixture containing polymeric wastes, which were combined to the ratio of 2: 2: 2: 1 for PE, PP, PET and PS on the basis of weight fraction, was also studied and analyzed in the same way. Theoretical activation energies (En,) of mixtures were calculated and compared with experimental activation energy (Ea) obtained by Flynn-Wall method. The nonisothermal kinetic results of polymeric wastes showed that most of polymeric wastes had single step reactions and similar activation energies for observed ...
The synthesis, characterization and thermogravimetric study of the adducts ZnCl2.2Imi, ZnBr2.2Imi, CdCl.Imi, CdCl2.2Imi, CdBr2.2Imi, CdBr2.3Imi, CdI2.2.5Imi, HgCl2.2Imi, HgBr2.1.5Imi and HgI2.1.5Imi (Imi = imidazole) is reported. The following sequence of thermal stability is observed for the synthesized adducts: Zn , Hg , Cd. It is also verified that larger cations, as well as larger anions, result in a smaller number of imidazole molecules in the coordination sphere of the considered cation and that hard acids exhibit stronger bonds to imidazole than soft acids, and this fact is reflected in the thermal stability sequence. ZnCl2.2Imi behaves as a non-electrolyte in acetonitrile and ethanol, whereas ZnBr2.2Imi is a non-electrolyte in acetonitrile and a 1:1 electrolyte in ethanol. CdI2.2.5Imi is a non-electrolyte in acetonitrile and a 1:2 electrolyte in ethanol. (C) 2003 Elsevier B.V. All rights reserved ...
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A gravimetric analysis of a metal carbonate is a process used to determine the chemical composition of an unknown metal carbonate. The metal carbonate is weighed, dissolved in water and a solution of...
A new polyester containing diimine ring, poly(imino isophthaloyl imino (glyoxal bis(2-methyl-4-hydroxy phenyl)imin)) poly[IPIGI] was synthesized by an Interfacial polycondensation reaction. The structure of poly[IPIGI] was confirmed by FT-IR and solid state 13C NMR techniques. The thermal stability was tested by TG-DTA and solubility was also studied. The kinetics of the thermal degradation of poly[IPIGI] was investigated by thermogravimetric analysis at different heating rates. TG curves showed that the thermal decomposition of poly[IPIGI] occurred in two stages. The apparent activation energies of thermal decomposition for poly[IPIGI], as determined by the Tang method (TM), the Flynn-Wall-Ozawa method (FWD), the Kissenger-Akahira-Sunose method (KAS) and the Coats-Redfern method (CR) are 74.8, 75.2, 76.5 and 83.9 kJ mol-1 for the first stage decomposition and 143.1, 143.7, 147.0 and 156.2 kJ mol-1 for the second stage decomposition, respectively. The mechanisms of each stage decomposition were also
Abstract : The p-anisidine is widely used as chemical intermediate in the production of various dyes, pigments, and pharmaceuticals. This study was aimed to evaluate the effect of biofield energy treatment on the physicochemical and spectroscopic properties of p-anisidine. The study was performed after dividing the sample in two groups; one was remained as untreated and another was subjected to Mr. Trivedis biofield energy treatment. Afterward, both the control and treated samples of p-anisidine were evaluated using X-ray diffraction (XRD), surface area analyzer, differential scanning calorimetry (DSC), thermogravimetric analysis-derivative thermogravimetry (TGA-DTG), Fourier transform infrared (FT-IR), and ultraviolet-visible (UV-Vis) spectroscopy. The XRD analysis showed the increase in unit cell volume from 683.81 → 690.18 × 10-24 cm3 and crystallite size from 83.84→84.62 nm in the treated sample with respect to the control. The surface area analysis exhibited the significant increase ...
Abstract : The Murashige and Skoog medium (MS media) is a chemically defined and widely used as a growth medium for plant tissue culture techniques. The present study was attempted to evaluate the impact of biofield energy treatment on the physical, thermal, and spectral properties of MS media. The study was performed in two groups; one was kept as control while another was subjected to Mr. Trivedis biofield energy treatment and coded as treated group. Afterward, both the control and treated samples were analyzed using various analytical techniques. The X-ray diffraction (XRD) analysis showed 19.92% decrease in the crystallite size of treated sample with respect to the control. The thermogravimetric analysis (TGA) showed the increase in onset temperature of thermal degradation (Tonset) by 9.41% and 10.69% in first and second steps of thermal degradation, respectively after the biofield energy treatment as compared to the control. Likewise, Tmax (maximum thermal degradation temperature) was ...
This paper reports the synthesis of Co3O4-reduced graphene oxide (rGO) hybrids and the catalytic performance in heterogeneous activation of peroxymonosulfate (PMS) for the decomposition of phenol. The surface morphologies and structures of the Co3O4-rGO hybrids were investigated by field emission scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Through an in situ chemical deposition and reduction, Co3O4-rGO hybrids with Co3O4 nanoparticles at an average size of 33 nm were produced. Catalytic testing showed that 20 mg/L of phenol could be completely oxidized in 20 min at 25 °C on Co3O4-rGO hybrids, which is mostly attributed to the generation of sulfate radicals through Co3O4-mediated activation of PMS. Phenol oxidation was fitted by a pseudo-zero-order kinetic model. The rate constant was ...
purpose. To analyze free and total water in human normal and cataractous lenses.. methods. Thermogravimetric analysis was used to determine total water, and differential scanning calorimetry was used for free water.. results. In normal human lenses, the total water content of the nucleus remained unchanged with age, but the state of the water altered. The ratio of free to bound water increased steadily throughout adult life. In a 20-year-old person, there was approximately one bound water molecule for each free water molecule in the lens center, whereas in a 70- to 80-year-old person, there were two free water molecules for each bound water molecule. This conversion of bound to free water does not appear to be simply a consequence of the aggregation of soluble crystallins into high molecular weight aggregates because studies with intact pig lenses, in which such processes were facilitated by heat, did not show similar changes. The region of the lens in which the barrier to diffusion develops at ...
SFRE 199-1 medium (SFRE-M) is important mammalian cell culture medium, used for the culture of primary cells of mammals such as baboon kidney cells. The present study was attempted to evaluate the impact of biofield energy treatment on the physical, thermal and spectral properties of SFRE-M. The study was accomplished in two groups; one was set as control while another was subjected to Mr. Trivedis biofield energy treatment and coded as treated group. Subsequently, the control and treated samples were analyzed using various analytical techniques. The CHNO analysis showed about 2.16, 4.87, and 5.89% decrease in percent contents of carbon, hydrogen, and oxygen, respectively; while 9.49% increase in nitrogen contents of treated sample as compared to the control. X-ray diffraction (XRD) analysis showed 7.23% decrease in crystallite size of treated sample as compared to the control. The thermogravimetric analysis (TGA) analysis showed the increase in onset temperature of thermal degradation by ...
Conductive polymer blends of polypyrrole (PPy) and poly(ethylene oxide) (PEO) were obtained in the form of films and fibers, respectively by solvent casting and electrospinning. Different amounts of PPy were introduced in the blends in order to study the effect of the conductive polymer on the properties of the final material and in particular to elucidate the influence of the different morphology on conductivity. The structure and morphology of PPy/PEO blends were characterized by wide angle X-ray diffraction (WAXD) and small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to understand the influence of different PPy content on thermal behavior and stability, electrospun fibrous mats were examined by scanning electron microscopy (SEM ...
The immobilization of Amano Lipase A from Aspergillus niger by adsorption onto Stöber silica matrix obtained by sol-gel method was studied. The effectiveness of the enzyme immobilization and thus the usefulness of the method was demonstrated by a number of physicochemical analysis techniques including Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis (EA), thermogravimetric analysis (TG), porous structure of the support and the products after immobilization from the enzyme solution with various concentration at different times. The analysis of the process kinetics allowed the determination of the sorption parameters of the support and optimization of the process. The optimum initial concentration of the enzyme solution was found to be 5 mg mL-1, while the optimum time of the immobilization was 120 minutes. These values of the variable parameters of the process were obtained by as ensuring the immobilization of the largest possible amount of the biocatalyst ...
The aim of this study was to explore the utilization of industrial bio-residues as a source of raw material for the industrial production of cellulose nanowhiskers. The used residue, obtained from a bioethanol pilot plant, was first purified using chemical extraction and bleaching, and then separated to nanowhiskers by mechanical treatments such as ultrasonication, high-pressure homogenization as well as chemical acid hydrolysis.The chemical compositions and characteristics of the bio-residue were studied before and after purification using a TAPPI standard, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The morphology of the isolated nanowhiskers was characterized using atomic force microscope (AFM). The chemical composition of the used bio-residue was found to be 49.5 wt% cellulose, 42.1 wt% lignin and 8.4 wt% extractives. The crystallinity of the bio-residue was 14.5% and it increased to more than 73% after the purification ...
A TG/FTIR instrument that combines thermogravimetric analysis with evolved products analysis by Fourier transform infrared spectroscopy is a powerful thermo-analytical technique providing a quantitative time-resolved analysis of major pyrolysis products of any bio-originated material including tobacco. In this work, we demonstrate how the time-resolved spectra of TG/FTIR along with the target factor analysis (TFA) can be used to identify and then quantify the pyrolysis products.
A series of Fe-Ce-Ti catalysts were prepared via co-precipitation method to investigate the effect of doping Ce into Fe-Ti catalysts for selective catalytic reduction of NO with NH3. The NO conversion over Fe-Ce-Ti catalysts was considerably improved after Ce doping compared to that of Fe-Ti catalysts. The Fe(0.2)-Ce(0.4)-Ti catalysts exhibited superior catalytic activity to that of Fe(0.2)-Ti catalysts. The obtained catalysts were characterized by N2 adsorption (BET), X-ray diffraction (XRD), temperature programmed reduction (H2-TPR), temperature programmed desorption (NH3-TPD), Fourier transform infrared (FT-IR) spectrophotometry, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The data showed that the introduction of Ce results in higher surface area and better dispersion of active components on the catalyst surface and enhances the amount of surface acid sites. The interactions between Fe and Ce species were found to improve the redox ability of the catalyst, which
Abstract ZnO-poly(2-cinnamoyloxyethyl methacrylate) and ZnO-poly(2-cinnamoyloxyethyl methacrylate)-b-poly[(poly(ethylene glycol) methyl ether methacrylate] have been prepared by atom transfer polymerization initiated through a 2-bromoisobutyryl or bromoethyl group linked onto the ZnO nanoparticle surface (ZnO-BIBB, ZnO-BEI). The structure and morphology of the hybrids were characterized using Fourier transform infrared, proton nuclear magnetic resonance, fluorescence and UV spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron (TEM) and atomic force microscopy. The existence of nanoparticles with diameters varying between 40 and 100 nm was evident in the TEM images of the pure ZnO, ZnO-PCEMA-Br-2 and the diblock copolymer. Under an excitation of 340 nm, these materials exhibit a broad emission band at around 390 nm, which was associated with the presence of ZnO in the organic matrix. Graphical abstract ...
Lipases from Burkholderia cepacia (Amano PS) and Candida antarctica B (CalB) were immobilized by sol-gel entrapment techniques, using a ternary silane precursors system with vinyl and phenyl non-hydrolyzable groups. The influence of temperature on the catalytic properties of native and immobilized lipases was investigated by incubating the biocatalysts for 24 h at temperatures between 40 C and 80 C, in n-hexane medium. A long term stability study was made with immobilized CaLB biocatalysts by incubation for 120 h in isooctane at 80 C. The acylation of aliphatic sec-alcohols by vinyl acetate was used as model reaction. Thermogravimetric analysis (TGA) was employed to evaluate the thermal stability and degradation of the immobilized biocatalysts ...
Lipases from Burkholderia cepacia (Amano PS) and Candida antarctica B (CalB) were immobilized by sol-gel entrapment techniques, using a ternary silane precursors system with vinyl and phenyl non-hydrolyzable groups. The influence of temperature on the catalytic properties of native and immobilized lipases was investigated by incubating the biocatalysts for 24 h at temperatures between 40 C and 80 C, in n-hexane medium. A long term stability study was made with immobilized CaLB biocatalysts by incubation for 120 h in isooctane at 80 C. The acylation of aliphatic sec-alcohols by vinyl acetate was used as model reaction. Thermogravimetric analysis (TGA) was employed to evaluate the thermal stability and degradation of the immobilized biocatalysts ...
Filler-filled natural rubber (NR) vulcanizates were prepared by conventional laboratory-sized two roll mills and cured using sulfuric system. The effect of thermal aging on physical properties and thermogravimetric analysis (TGA) of oil palm ash (OPA) and commercial fillers (i.e., silica vulkasil C and carbon black N330)-filled NR vulcanizates at respective optimum loading and equal loading were studied. Before aging, the OPA-filled vulcanizates showed comparable optimum strength as carbon black-filled vulcanizates. The hardening of aged filler-filled NR vulcanizates happened after aging, thereby tensile strength and elongation at break reduced while the modulus increased. Fifty phr carbon black-filled vulcanizates showed better retention in tensile properties as compared to silica (10 phr) and OPA (1 phr). This was attributed to the addition of different filler loading and this finding was further explained when equal loading of filler-filled vulcanizates was studied. Fourier transform ...
A new complex involving 1,3-bisbenzyl-2-oxoimidazoline-4,5-dicarboxylic acid (H2L) and a cobalt(ii) metal ion designated [Co(L)(H2O)2]n has been synthesized under solvothermal conditions and characterized by elemental analyses, IR spectra, thermogravimetric analysis, single crystal X-ray diffraction and magn
Bacterial biofilms constitute an extremely resistant form of bacterial colonization with dire health and economical implications. Towards achieving polymeric composites capable of resisting bacterial adhesion and biofilm formation, we prepared five 2,6-pyridinedicarboxylate-based polyesters employing five different diol monomers. The resulting polyesters were complexed with copper (II) or silver (I). The new polymers were characterized by proton and carbon nuclear magnetic resonance spectroscopy, inherent viscosity, infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. The corresponding metal complexes were characterized by differential scanning calorimery and infrared spectroscopy. The amounts of complexed copper and silver were determined by atomic absorption spectrophotometry. Finally, the resulting composites were tested for their antibacterial potential and were found to effectively resist bacterial attachment and growth.
A novel cadmium phosphonate compound Na-2[Cd-2(H2O)(3)(O3PCH(OH)CO2)(2)] (.) 2H(2)O (1) has been synthesized by hydrothermal reaction at 120 degrees C and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The structure of compound 1 comprises CdO6 octahedra and CdO7 pentagonal bipyramid connected by [O3PCH(OH)CO2](3-) to form a 2D layered structure with a one-dimensional channel system and the charge-compensating Na+ cations being located between two adjacent layers. (c) 2006 Elsevier B.V. All rights reserved ...
Mesoporous carbon microfibers (MCMFs) were prepared using one-dimensional alumina microfibers as the templates via chemical vapor deposition method. Physical adsorption of nitrogen, X-ray diffraction, thermogravimetric analysis, field-emission transmission electron microscopy, energy dispersive X-ray analysis, and field-emission scanning electron microscopy techniques were used to study the structure and morphology of the samples. MCMFs possess a core/shell structure with a surface area of 409 m2/g. The core structure of the obtained MCMFs was composed of mesopores with a pore size of 8.8 nm, whereas the dense shell with a thickness of around 15-20 nm was built up with roughly parallel discrete graphene layers. Compared with Pt catalyst supported on Vulcan XC-72, catalyst supported on MCMFs displayed a better CO tolerance and catalytic activity in electrooxidation of methanol at room temperature. © 2007 American Chemical Society ...
Chitin nanowhiskers are structured into mesoporous aerogels by using the same benign process used previously in our group to make cellulose nanowhisker aerogels. The nanowhiskers are sonicated in water to form a hydrogel before solvent-exchange with ethanol and drying under supercritical CO2 (scCO2 ). Aerogels are prepared with various densities and porosities, relating directly to the initial chitin nanowhisker content. scCO2 drying enables the mesoporous network structure to be retained as well as allowing the gel to retain its initial dimensions. The chitin aerogels have low densities (0.043-0.113 g cm(-3) ), high porosities (up to 97 %), surface areas of up to 261 m(2) g(-1) , and mechanical properties at the high end of other reported values (modulus between 7 and 9.3 MPa). The aerogels were further characterized by using X-ray diffraction, BET analysis, electron microscopy, FTIR, and thermogravimetric analysis. Characterization showed that the rod-like crystalline nature of the nanowhiskers was
The THEMYS is the NEW benchmark for modular thermogravimetric analysis. The THEMYS is available in various platforms: TGA, STA, TG/DSC, EGA...
The analytical center in Matexcel has adopted a comprehensive set service line that includes some of the most advanced instruments: dynamic light scattering (DLS), Raman spectroscopy, thermogravimetric analysis (TGA), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).. "We feel quite honored to have our nano-bio services enhanced. Our nanomaterial scientists are always ready to support you with your data analysis and product enhancement. We are planning to update our surface modification services in the next weeks," commented a representative speaker from Matexcel.. To get more detailed information about the nano-bio services in Matexcel, you can visit https://www.matexcel.com/services/nano-bio-service.. About Matexcel. Matexcel is a leading service provider in materials science, with years of commitment to supply better polymers, nanoparticles and other materials for worldwide customers from both academia and industry.. Media Contact ...
The nano-sized copper tungstate (CuWO4) was prepared by precipitation method in the presence of non-ionic copolymer surfactant (polyoxyethylene-polyoxypropylene block copolymer) and consequent annealing at low temperature (400 degrees C). The scanning electron microscopy (SEM) indicated formation of spherical CuWO4 particles in the size range from 10 to 90 nm. The thermogravimetric analysis was used to study dehydration processes. The X-ray diffraction analysis undoubtedly confirmed formation of triclinic CuWO4 and the refinement of the diffraction data showed that CuWO4 powder belongs to the distorted tungstate type of structure with space group P (1) over bar. The structure of the CuWO4 can be described as infinite zigzag chains formed by edge-sharing alternating [W-O-6] and [Cu-O-6] octahedra. Indirect and direct band-gap energies of CuWO4 (2.3 and 3.5 eV, respectively) were determined using optical measurements ...
In addition to the above the department also has:. GC/MS with EI, CI and direct insert capability (ThermoFisher Focus GC and PolarisQ MS). FTIR Spectrometers (Nicolet Nexus 670, Nicolet Avatar 360 and Perkin Elmer Spectrum Two). Raman Spectrometer (DeltaNu Advantage 200A). Atomic Absoption Spectometer (Varian SpectrAA 220/FS). UV/Vis Spectrometer (Varian Cary 300 Bio). Differential Scanning Calorimeters (Perkin Elmer Diamond DSC and Perkin Elmer DSC 7). Fluorimeter (Horiba Jobun Yuon FluoroMax-4). Thermogravimetric Analysis (TGA 50). HPLC (HP 1100s and HP 1090s, equipped with Size Exclusion Chromatography/Gel Peremeation Chromoatrgaty, Chiral Chromatography). Viscometer (Wyatt Viscostar with Optilab rEX). Cyclic voltammetry (BAS CV-50V Voltammetric Analyzer). Microwave Digester (Milestone Microwave Lab Systems). Inert Atmosphere Glove Box (MBraun Unilab). Solvent Purification System (MBraun MB-SPS). 60 MHz NMR (Varian E360 with Anasazi FT upgrade). ...
In this paper, β-phase depletion behaviour of free-standing high velocity oxy-fuel (HVOF) thermally sprayed CoNiCrAlY coatings was studied. Microstructural analysis showed a two-phase microstructure of γ-Ni matrix and β-NiAl secondary phase after heat treatment. Fine grains were found around the sprayed particle boundaries and coarse grains were retained as the original particle structure, with grain sizes varying from 2 to 0.5 μm or even less for both phases. The β-phase depletion behaviour was investigated during isothermal oxidation and was also modelled through diffusion calculations. A previously developed β-phase depletion model was utilised to study the evolution of β-phase depletion under different oxide growth kinetics. Three oxide growth models were tried: 1) Meier model, 2) thermogravimetric analysis (TGA) model, and 3) experimentally fitted oxide growth model. The oxide growth kinetics were converted to Al flux functions which were used as the boundary conditions in the DICTRA ...
LIMA, Antonio L. dos Santos et al. Mesophase evolution in heat-treated solid petroleum pitches. J. Braz. Chem. Soc. [online]. 2012, vol.23, n.7, pp.1355-1371. ISSN 0103-5053. http://dx.doi.org/10.1590/S0103-50532012000700021.. A combination of analytical techniques was used to follow the mesophase evolution of petroleum pitches in the solid phase. The samples were characterized by matrix assisted laser desorption and time of flight analysis by mass spectrometry (MALDI-TOF-MS), high field 13C nuclear magnetic resonance (13C NMR), low field 1H NMR, electron spin resonance (EPR), polarized optical microscopy and thermogravimetric analysis (TGA). MALDI-TOF-MS revealed an oligomeric distribution of molecular weights in the pitch: monomeric (m/z 200 to 400), dimeric (m/z 400 to 650), trimeric (m/z 650 to 950) and tetrameric (m/z 950 to 1600), an essential factor for the production of carbon fibers, among other advanced composite of carbon. Relaxation time (T1) studies permitted to observe two large ...
From thermogravimetric analysis studies (ESI - Fig. S1†) compound I, [C6H9N2O][SbI4], shows a stable mass with negligible change on heating to approximately 210 °C, followed by a major degradation step (Δm% = −86%) between 210 and 320 °C. This is likely to be associated with complete decomposition of the amine and loss of iodine from the material; the fastest mass loss occurs from 280-300 °C. A further steady low rate of mass loss occurred on heating to the maximum furnace temperature of 400 °C; leaving residual mass (∼1.2 mg) of antimony metal. For compound II, [C6H9N2O][BiI4], a stable thermal profile is observed up to 150 °C before a series of sharp, small, weight losses, equating to total loss (Δm%) of 10%, occurs between 150 and 210 °C. These weight losses can be attributed rapid, possibly locally explosive decomposition of the amine. The remaining bulk mass is stable to 250 °C before undergoing a continuous large mass loss step (Δm% = 70%) on heating to 400 °C, with the ...
The study presents the possibility of coupling quercetin into poly(N,N-dimethylacrylamide-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane) (PDMA-co-U) gel network through a semi-imprinted procedure in order to obtain a responsive antioxidant composite. A continuous magnetic field was used during quercetin insertion for prearranging the compounds - macromolecular matrix and quercetin - and improving the coupling efficiency of the flavonoid structure into the polymeric network. The new supramolecular systems were characterized by FTIR, SEM and thermogravimetric analyses. The dependence of the swelling degree equilibrium and particle size distribution of the studied chemical structures were also evaluated related to the experimental conditions of preparation.
The thermal decomposition of studtite (UO2)O2(H2O)2·2H2O results in a series of intermediate X-ray amorphous materials with general composition UO3+x (x = 0, 0.5, 1). As an extension of a structural study on U2O7, this work provides detailed calorimetric data on these amorphous oxygen-rich materials since their energetics and thermal stability are unknown. These were characterized in situ by thermogravimetry, and mass spectrometry. Ex situ X-ray diffraction and infrared spectroscopy characterized their chemical bonding and local structures. This detailed characterization formed the basis for obtaining formation enthalpies by high temperature oxide melt solution calorimetry. The thermodynamic data demonstrate the metastability of the amorphous UO3+x materials, and explain their irreversible and spontaneous reactions to generate oxygen and form metaschoepite. Thus, formation of studtite in the nuclear fuel cycle, followed by heat treatment, can produce metastable amorphous UO3+x materials that ...
|p> We have investigated the possibility of avoiding formation of Er-rich oxide clusters in ErAl3O6-TiO2-SiO2 glassy films. Samples containing 0.5, 1 and 3 mol% Er31 were prepared using a precursor with a single, isolated Er-ion, ErAl3(OPri)12, in the metal-organic sol-gel route. The thermal decomposition of the gel films to form amorphous oxide films was studied by thermogravimetry, Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction and by means of a transmission electron microscope, equipped with an energy dispersive spectrometer. The microscopy studies of the oxide films obtained after 2 h at 9008C showed that they were amorphous and free of Er-rich clusters. The optical and vibrational properties of the glasses were studied using FT-IR, Raman scattering and luminescence spectroscopy. The samples exhibit luminescence both in the visible and IR under excitation of the 514.5 and 488 nm Ar1 laser lines. The emission around 1.5 mm was maximum for the 1 mol% sample. The results show
A dense monolithic intermetallic Al3Ti alloy was successfully synthesized via reactive sintering in vacuum using TC4 alloy and pure aluminum foils with appropriate initial thickness. Energy dispersive spectroscopy (EDS), x-ray diffractometry (XRD), and scanning electron microscopy (SEM) were used to characterize the phase and microstructure of Al3Ti alloy. Ultrasonic measurement was performed to evaluate the physical property of Al3Ti alloy. Different thermal analysis, thermogravimetry (TG) and differential scanning calorimetry (DSC) were used to assess the thermal property of Al3Ti alloy. The compressive tests were carried out on a universal load frame to determine the mechanical properties, including the compressive strength and failure strain of the fabricated intermetallic Al3Ti alloy. The current results indicated that the density of Al3Ti alloy is slightly higher than the theoretical density, the average Youngs modulus is lower than the theoretical value. A trace of aluminum in Al3Ti ...
Radiation damage in minerals is caused by the alpha-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400-1400 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG) (Zietlow et al., in print). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia (6.4 wt% Th, 23.1·1018 α-decay events per gram (dpg)), Zlatoust/Russia (6.3 wt% Th, 23.1·1018 dpg), Panda Hill/Tanzania (1.6 wt% Th, 1.6·1018 dpg), and Blue River/Canada (10.5 wt% U, 115.4·1018 dpg), are compared with a crystalline reference pyrochlore from Schelingen (Germany). The type of structural recovery depends on the initial degree of radiation damage (Panda Hill 28 %, Blue River 85 %, Zlatoust and Miass 100 % according to XRD), as the recrystallization temperature increases with increasing degree of amorphization. Raman spectra
Layered double hydroxides having different cationic (Mg2+, Co2+, Al3+) composition were successfully synthesized by the low supersaturation method. The samples were thermally decomposed and reconstructed using water and nitrate media at different temperatures. X-ray powder diffraction analysis, X-ray fluorescence analysis, thermogravimetry and BET/BJH methods were used to investigate the differences between the directly obtained layered materials and those after the reconstruction process.. DOI: http://dx.doi.org/10.5755/j01.ms.23.2.15184. ...
Small amounts of carbon fibers (about 5%) were determined in samples containing polyphenylene sulfide (PPS), inorganic filler (glass in this case), and polytetrafluoroethylene (PTFE) by means of thermal analysis using both thermogravimetry (TG), and differential scanning calorimetry (DSC). Two different, but related, methods were used to quantitatively determine the contents of the sample. The first, which was nominally called the "Indirect Approach," utilizes DSC for the determination of the polymeric components and TG for the determination of the residue (inorganic fillers or glass or both). The amount of carbon is then determined by difference. The second method, which was nominally called the "Direct Approach," utilizes DSC for the determination of PTFE and TG for the determination of all other components. The agreement between the two methods is good.. ...
Figure 1. Forged PIECE (Henkel BV) and crystallographic structure of graphite. For substituting the graphite, inorganic materials are the best candidates for their well-known stabilities in temperature and against corrosive agents. A new class of soft ceramics is developed in this project.. This assignment addresses the synthesis of fine-tuned soft-ceramics assisted by wet chemistry, microwave and solid state reactions. All the products will be characterized by available techniques such Infrared Spectroscopy (IR), Electron Microscopy (SEM-TEM), X-ray Diffraction (XRD) and Thermogravimetry (TGA-DSC). The best products will be tested in a pin-on-disc tester for knowing the lubricious properties.. For further information, contact Pablo Gonzalez ([email protected]) ...
Bismuth oxide (Bi2O3) nanorods was prepared via one pot sol-gel method using Bi(NO3)3.5H2O and starch (as template) in water under hydrothermal condition followed by calcination at 320˚C within 3 h. The resultant solid product was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetry (TGA), and FTIR techniques. Based on the obtained results, the formation of Bi2O3 nanoparticles and nanorods at lower and higher percentage of starch is promising. It was found that Bi2O3 nanorods catalyse the aromatization of 1,4-dihydropyridines (DHPs) with 100% conversion and 100% selectivity.
The activities of this research team involve several areas. The first area is diagnostics of materials and structural analysis. This part of the team deals with the diagnostics of insulating systems of electrical machines and devices from the point of view of their properties relating to the measurement of insulation resistance, short-circuit factors, capacity and partial discharges. Apart from the electrical tests, mechanical tests are performed, for example, the measurement of tensile strength, compression strength and bending strength. Of all the structural analysis methods employed in this research workplace, it is necessary to mention thermal-mechanical analysis, dynamic-mechanical analysis, thermogravimetry, differential scanning calorimetry and infra-red spectroscopy with the Fourier transformation.. The second area of interest involves the diagnostics of electronics components, printed-circuit boards and linkage structures. In this area, the microscopy laboratory is frequently exploited, ...
Meets AP Science Practices 1, 2, 4, 5, 6, and 7Illustrate a variety of key chemistry concepts using the materials provided by these demonstrative lab activity kits. Explore common chemistry concepts such as the interaction of chemicals in controlled reactions, the formation of precipitates, and more spectacular reactions. These latter reactions can help students become familiar with chemical principles such as redox, synthesis, decomposition, ionic reactions in aqueous solutions, and exothermic reactions. Starter sets and comprehensive kits include all the reaction plates, pipettes, and more that may be required for performing reactions.