共查询到20条相似文献,搜索用时 62 毫秒
1.
Yu Huimei Qi Lingjun Zhang Qinghong Jiang Danyu Lu Changwei 《Journal of Thermal Analysis and Calorimetry》2011,106(1):47-52
The thermal behavior of the anticancer drug-irinotecan was measured by Thermogravimetry–Differential thermal analysis (TG–DTA)
to explore the application of TG–DTA in nanomedicine firstly. The TG–DTA result showed that the irinotecan was oxidized completely
before 700 °C. When irinotecan was loaded onto nanosized mesoporous silica spheres, the loading capacity for irinotecan measured
by TG–DTA was about 9.11% in the irinotecan/mesoporous SiO2 composite, similar to the typical UV–Vis spectra results (10.5%), which showed that TG–DTA characterization provided an alternative
method to determine the drug loading amount on inorganic carriers. Secondly, Thermogravimetry–Differential scanning calorimetry–Mass
Spectrometry coupling techniques (TG–DSC–MS) were used to characterize the hydrogen adsorption temperature and capacity of
TiCr1.2 (V-Fe)0.6 alloy. The MS result showed that the released region of hydrogen was 250–500 °C, which was consistent with the TG–DSC results.
Lastly, TA–MS combined with pulse thermal analysis (PulseTA) were used for a simultaneous characterizing study in the changes
of mass, determination and quantitative calibration of the evolved nitrogen formed during the thermal decomposition of the
InN powder. The results showed that relative error of this method between measured value and theoretical value was 2.67% for
the quantitative calibration of evolved N2. It shows that TA–MS combined with PulseTA techniques offer a good tool for the quantification of the evolved nitrogen in
the InN powder. 相似文献
2.
J.L. Perez-Rodriguez A. Duran M.A. Centeno J.M. Martinez-Blanes M.D. Robador 《Thermochimica Acta》2011,512(1-2):5-12
This work describes the thermal transformation of patina samples formed on the surface of dolomitic rocks used to build the Romanesque Torme's Church (Burgos, Spain). Analyses were performed using a combination of high-temperature XRD, simultaneous TG/DTA and gas mass spectrometry. The XRD analysis revealed the presence of hydrated calcium oxalates. The following three steps were proposed for the thermal transformation of the raw material: dehydration of weddellite/whewellite to form calcium oxalate, transformation of calcium oxalate to calcium carbonate, and formation of calcium oxide produced via decomposition of the calcite. DTA/TG and mass spectrometry analyses confirmed this mechanism. In addition, a high proportion of organic compounds was detected and was possibly formed via degradation of products applied for the building's conservation by the action of microorganisms attack. Mass spectrometry analysis revealed CO (and CO2) gas evolved during the transformation of CaC2O4 to CaCO3. The CO2 gas also appears at 765 °C due to the decomposition of calcium carbonate, and it appears over a large range of temperatures due to the decomposition of organic compounds. The TG analyses performed in a CO2 atmosphere were used to determine the percentages of Ca and Mg contained in dolomite, and the calcium carbonate formed by oxalate decomposition. DRIFTS and mass spectrometry results revealed the presence of several aliphatic and/or aromatic compounds containing CO groups. 相似文献
3.
1,2,4-triazole-3-one (TO) and guanidine nitrate (GN) have the potential to be used as alternative gas-generating agents. To
obtain a better understanding of thermal decomposition properties of TO/GN mixtures, sealed cell differential scanning calorimetry,
thermogravimetry–differential thermal analysis–infrared spectroscopy (TG–DTA–IR), and thermogravimetry–differential thermal
analysis–mass spectrometry (TG–DTA–MS) were carried out. The endothermic peak and onset temperatures of TO/GN mixtures were
lower than those of individual TO and GN. TG–DTA–IR and TG–DTA–MS showed that the mass of TO/GN mixtures decreased with heat
generation and N2 evolved as the major gas during thermal decomposition. The interaction between TO and nitric acid from the dissociation of
GN is proposed for the thermal decomposition of TO/GN mixtures. 相似文献
4.
Rodrigo A. de Souza Antonio E. Mauro Adelino V. G. Netto Gislaine A. da Cunha Eduardo T. de Almeida 《Journal of Thermal Analysis and Calorimetry》2011,106(2):375-378
Palladium(II) coordination compounds of general formula trans-[PdX2(isn)2], X = Cl− (1), N3
− (2), SCN− (3), NCO− (4), isn = isonicotinamide; were synthesized and characterized in solid state by elemental analysis, infrared spectroscopy,
and simultaneous TG–DTA. TG experiments reveal that the compounds 1–4 undergo thermal decomposition in three or four stages, yielding Pd0 as final residue, according to calculus and identification by X-ray powder diffraction. 相似文献
5.
Wenxian Wei Bingbing Cui Xiaohong Jiang Ludu Lu 《Journal of Thermal Analysis and Calorimetry》2010,102(3):863-866
The catalytic effect of NiO on thermal decomposition of nitrocellulose (NC) has been investigated via thermogravimetry–mass
spectrometry (TG–MS) coupling technique, and the residue of NC with 20% NiO reacted in tubular furnace was analyzed by X-ray
diffraction (XRD). TG–MS analysis showed that adding 2% NiO to NC accelerated the thermal decomposition process and promoted
the generation of gaseous products. The catalytic mechanism was based on the accelerated generation of NO2, which further reacted with the radical to produce other gaseous products. XRD analysis of catalyst residue showed that Ni
was formed during the catalytic reaction. 相似文献
6.
G. Madhurambal M. Mariappan B. Ravindran S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2011,104(3):885-891
Mixed crystals of various proportions of urea thiourea were grown by slow evaporation of aqueous solution at room temperature.
The bright and transparent crystals obtained were characterized using thermogravimetry–differential thermal analysis (TG–DTA)
and FTIR spectroscopic analyses. A fitting decomposition pattern for the title compound was formulated on the TG curve which
shows a two-stage mass loss between 175 and 750 °C. In this temperature range, DTA curves show exothermic peaks supporting
the formulated decomposition pattern. The FTIR spectra show the characteristic absorption, vibration frequencies due to urea
thiourea. Detailed structural analysis of the compound is under progress. 相似文献
7.
A. Kohutova P. Honcova V. Podzemna P. Bezdicka E. Vecernikova M. Louda J. Seidel 《Journal of Thermal Analysis and Calorimetry》2010,101(2):695-699
Thermal decomposition and structural characterization of three human kidney stones (KS1–KS3) extracted from patients of Eastern
Bohemia have been carried out using X-ray powder diffraction systems (XRD), scanning electron microscope with energy dispersive
X-ray micro analyser (SEM-EDX) and differential thermal analysis (DTA). The samples KS1 and KS2 solely consisted of calcium
oxalate monohydrate (a.k.a. whewellite, CaC2O4·H2O). The third sample, KS3, was formed from calcium oxalate dihydrate (weddellite, CaC2O4·2H2O), calcium oxalate monohydrate, and hydroxyapatite (HA, Ca10(PO4)6(OH)2). Thermal measurements were carried out in the range between room temperature and 1,230 °C. XRD analysis was utilized to
investigate the change of phases at 800 and 1,230 °C. 相似文献
8.
Bapat L. Natu G. N. Kher J. Bhide M. 《Journal of Thermal Analysis and Calorimetry》2000,62(1):285-294
Reactivity of mixtures of La(III) oxide and Cu(II) oxalate/nitrate in hydrated as well as anhydrous state was studied using
TG, DTA and XRD.
Cu(II) oxide formed in the endothermic decomposition of mixture containing hydrated Cu(II) nitrate and La(III) oxide could
not form La2CuO4 while Cu(II) oxide formed in the exothermic decomposition of mixture containing hydrated/anhydrous Cu(II) oxalate and La(III)
oxide reacts with La(III) oxide and develops the phases CuLaO3 and La2CuO4.
The maximum reactivity with respect to the formation of La2CuO4phase was observed in mixture containing anhydrous Cu(II) oxalate.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
C. Păcurariu R. I. Lazău I. Lazău D. Tiţa A. Dumitrel 《Journal of Thermal Analysis and Calorimetry》2011,103(2):435-441
Thermal and structural properties of three clays (sepiolite and two kaolinites) from Turkey were studied by thermal analysis
(TG–DTA), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FT-IR), and surface area measurement
techniques The adsorption of sulfur dioxide (SO2) gas by these clays was also investigated. SO2 adsorption values of K1, K2, and S clay samples were measured at 20 °C and pressures up to 106 kPa. Sepiolite sample (S)
primarily consists of pure sepiolite, only dolomite present as accompanying mineral. Both kaolinite samples, K1 and K2, mainly
contain kaolinite as the major clay mineral and quartz as impurity. In K2 sample, muscovite phase is also present. Simultaneous
TG–DTA curves of all clay samples were obtained at three different heating rates 10, 15, and 20 °C min−1 over the temperature range 30–1200 °C. It was found that the retention value of SO2 by S clay (2.744 mmol/g) was higher than those of K1 (0.144 mmol/g) and K2 (0.164 mmol/g) samples. 相似文献
10.
Katarína Győryová J. Chomič Erika Szunyogová Lenka Piknová V. Zeleňák Zuzana Vargová 《Journal of Thermal Analysis and Calorimetry》2006,84(3):727-732
Three
new complex compounds of general formula Zn{4-ClC6H3-2-(OH)COO}2⋅L2⋅nH2O
(where L=thiourea (tu), nicotinamide (nam),
caffeine (caf), n=2,3), were prepared and
characterized by chemical analysis, IR spectroscopy and their thermal properties
were studied by TG/DTG, DTA methods. It was found that the thermal decomposition
of hydrated compounds starts with the release of water molecules. During the
thermal decomposition of anhydrous compounds the release of organic ligands
take place followed by the decomposition of salicylate anion. Zinc oxide was
found as the final product of the thermal decomposition performed up to 650°C.
RTG powder diffraction method, IR spectra and chemical analysis were used
for the determination of products of the thermal decomposition. 相似文献
11.
Xu Rui-Bo Xu Xing-You Li Shu-An Wang Ming-Yan Yang Xu-Jie Wang Da-Qi Huang Yu-Ping Xu Chun-Mei 《Structural chemistry》2010,21(5):1085-1091
A new Cd(II) coordination polymer, [Cd(PMP)2]
n
(1) [PMP = 1-phenyl-3-methyl-5-pyrazolone], has been synthesized by the reaction of Cd(CH3COO)2·2H2O with PMP and characterized by elemental analysis, IR spectrum, fluorescence spectrum, UV–vis spectrum, TG–DTA, and electrochemical
analysis. Single crystal X-ray diffraction reveals that the complex has a three-dimensional network. Each PMP acts as bidentate
bridging ligand and each Cd(II) center is surrounded by two O atoms and two N atoms from four different PMP ligands to form
distorted tetrahedral coordination geometry. The photoluminescence study shows the complex exhibited strong solid state blue
fluorescent emission at room temperature, and the TG–DTA analysis demonstrated that it has highly thermal stability. Furthermore,
the electrochemical property of the complex has been investigated for the first time in DMF by cyclic voltammetry, and the
results showed that it has an irreversible process. 相似文献
12.
K. Ramamurthi G. Madhurambal B. Ravindran M. Mariappan S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2011,104(3):943-947
The growth and characterization of a new non-linear organometallic crystal, potassium thiourea thiocyanide (PTT) is reported.
The growth of single crystals was accomplished by the slow evaporation solution growth method. The grown crystals were characterized
by XRD, TG–DTA, UV, and FTIR spectral analyses. PTT has good optical transmission in the entire visible region which is an
essential requirement for a non-linear crystal. TG curve of PTT undergoes complete decomposition between 176 and 1,000 °C
in three steps with corresponding three DTA peaks. The high thermal stability of organometallic crystals are due to strong
bonding existing between the conjugation layers of thiourea molecule and the potassium ions. 相似文献
13.
Hongqiang Qu Weihong Wu Yunhong Jiao Jixing Xie Jianzhong Xu 《Journal of Thermal Analysis and Calorimetry》2011,105(1):269-277
A flame-retardant wood was prepared using a series of insoluble molybdates through the double bath technique. The flame retardancy
of the wood samples was studied with the limiting oxygen index (LOI) method. The relationships between the flame-retardant
performance and the thermal property of wood were studied by the thermogravimetry (TG), derivative thermogravimetry (DTG),
differential thermal analysis (DTA), scanning electron microscopy (SEM), and the thermogravimetry–mass spectrometry (TG–MS)
analysis methods. The results showed that the insoluble molybdates, which were precipitated into the wood by the double bath
technique, can obviously improve the flame retardancy of wood. Similarly, the transition metal molybdates showed higher flame-retardant
efficiency than the main group metal molybdates do, which probably due to the thermal barrier effect that Fe2(MoO4)3 acts during the combustion of the samples. At the same time, Fe2(MoO4)3 catalyzed the dehydration and carbonization reactions of wood, and caused an increase in the amount of char produced, and
an improvement of the stability of the char residue. Moreover, the mass spectrometry results indicated that the excess transition
metal ions speed up the deep decomposition of the char residue, and resulting in the smoldering of wood. 相似文献
14.
Chun-Hong Jiang Li-Fang Song Cheng-Li Jiao Jian Zhang Li-Xian Sun Fen Xu Yong Du Zhong Cao 《Journal of Thermal Analysis and Calorimetry》2011,103(1):373-380
A three-dimensional lithium-based metal–organic framework Li2(2,6-NDC) (2,6-NDC = 2,6-naphthalene dicarboxylate) has been synthesized solvothermally and characterized by X-ray powder
diffraction, elemental analysis, FT-IR spectroscopy, thermogravimetry and mass spectrometer analysis (TG–MS). The framework
has exceptional stability and is stable to 863 K. The thermal decomposition characteristic of this compound was investigated
through the TG–MS from 293 to 1250 K. The molar heat capacity of the compound was measured by temperature modulated differential
scanning calorimetry (TMDSC) over the temperature range from 195 to 670 K for the first time. The thermodynamic parameters
such as entropy and enthalpy versus 298.15 K based on the above molar heat capacity were calculated. 相似文献
15.
Tiit Kaljuvee Merli Keelmann Andres Trikkel Rein Kuusik 《Journal of Thermal Analysis and Calorimetry》2011,105(2):395-403
The thermooxidative decomposition of four oil shale samples from Estonia, Jordan, Israel and Morocco and one sample of Estonian
oil shale derivative, semicoke, was studied with the aim to determine the characteristics of the process and the differences
of it related to the origin of oil shale. The experiments with a Setaram Setsys 1750 thermoanalyzer coupled to a Nicolet 380
FTIR Spectrometer were carried out under non-isothermal conditions up to 1000 °C at the heating rates of 1, 2, 5, 10 and 20 °C min−1 in an oxidizing atmosphere. A model-free kinetic analysis approach based on the differential isoconversional method of Friedman
was used to calculate the kinetic parameters. The results of TG–DTA–FTIR analyses and the variation of activation energy E along the reaction progress α indicated the complex character of thermooxidative decomposition of oil shale and semicoke,
being at that the most complicated for Estonian and Jordanian oil shale characterized by higher content of organic matter
as compared to the other samples studied. 相似文献
16.
K. Muraleedharan M. P. Kannan T. Ganga Devi 《Journal of Thermal Analysis and Calorimetry》2011,103(3):943-955
The thermal decomposition of potassium iodate (KIO3) has been studied by both non-isothermal and isothermal thermogravimetry (TG). The non-isothermal simultaneous TG–differential
thermal analysis (DTA) of the thermal decomposition of KIO3 was carried out in nitrogen atmosphere at different heating rates. The isothermal decomposition of KIO3 was studied using TG at different temperatures in the range 790–805 K in nitrogen atmosphere. The theoretical and experimental
mass loss data are in good agreement for the thermal decomposition of KIO3. The non-isothermal decomposition of KIO3 was subjected to kinetic analyses by model-free approach, which is based on the isoconversional principle. The isothermal
decomposition of KIO3 was subjected to both conventional (model fitting) and model-free (isoconversional) methods. It has been observed that the
activation energy values obtained from all these methods agree well. Isothermal model fitting analysis shows that the thermal
decomposition kinetics of KIO3 can be best described by the contracting cube equation. 相似文献
17.
C. Tănase Lucia Odochian N. Apostolescu A. Pui 《Journal of Thermal Analysis and Calorimetry》2011,103(3):1079-1085
The article is devoted to the study on the thermal behaviour of three species of edible mushrooms: Boletus edulis (foot and cap), Pleurotus ostreatus (foot and cap), Lactarius deterrimus (cap) by the TG–FTIR-coupled technique, in air, over the 30–900 °C temperature range. The analysis of the TG–DTG–DTA curves
reveals the thermal degradation mechanism to be complex and specific to every species under the recording conditions applied.
A similar degradation mechanism is noticed for the foot and cap of Pleurotus ostreatus in comparison with the Boletus edulis and Lactarius deterrimus species where the mechanisms are different. The TG–FTIR analysis, combustion heats and IR spectra of the starting samples
also support these results. The initial degradation temperatures from TG–DTG indicate the temperature range where these species
are thermally stable and their nutrient features maintained making them proper for food. The TG–FTIR analysis gives information
on the gaseous species evolved by the thermal degradation bringing thus a contribution to the elucidation of the changes developing
by processing the edible mushrooms (industrialization, conservation, culinary preparations, etc.) at temperatures above the
initial degradation temperature. At the same time, the environmental impact, when the mushroom failed cultures are burned,
is also important. 相似文献
18.
Mustafa Versan Kok 《Journal of Thermal Analysis and Calorimetry》2011,105(2):411-414
In this research, thermo-oxidative reactions of crude oils of different origin are determined in limestone matrix using simultaneous
thermogravimetry and differential thermal analysis (TG–DTA) systems. Two different reaction regions were identified known
as low temperature (LTO) and high temperature oxidation (HTO). Kinetic parameters of the samples were determined by four different
methods and the results are discussed. 相似文献
19.
E. Horváth J. Kristóf R. Kurdi É. Makó V. Khunová 《Journal of Thermal Analysis and Calorimetry》2011,105(1):53-59
Intercalation of a kaolinite-containing halloysite from Biela Hora (Slovakia) with urea was investigated by simultaneous TG–DTA,
XRD, FTIR (DRIFT), and Raman spectroscopy. The process of intercalation and thermal deintercalation was followed for the as-prepared
and the washed (with isopropanol) samples. The proposed structural model was supported by molecular mechanical calculations.
Incorporation of the intercalate (in 5 wt%) in molten polypropylene at 200 °C resulted in the complete delamination of the
mineral. It is supposed that gas formation as a result of urea decomposition between the layers prevents reorientation and
restructuring of the layers. 相似文献
20.
A. Bakolas E. Aggelakopoulou A. Moropoulou 《Journal of Thermal Analysis and Calorimetry》2008,92(1):345-351
Ceramic powder has been used as an artificial pozzolanic addition, in preparing pozzolanic mortars for the historic/traditional
structures’ construction. In order to evaluate the pozzolanic activity of ceramic powder, several pastes were prepared, by
mixing it with hydrated lime, in different ratios. The pastes were stored in standard conditions (RH=99±1%, T=25±1°C) and evaluated using thermal analysis (DTA/TG), X-ray diffraction (XRD), compressive strength tests and mercury intrusion
porosimetry (MIP), in time. The obtained results revealed that the compounds formed were CSH and C4ACH11 (monocarboaluminate) after 270 days of curing. The calcium hydroxide consumption increases as the initial amount of the ceramic
powder in the paste augments. The maximum strength development is obtained for ceramic powder/hydrated lime ratio 3:1. 相似文献