共查询到20条相似文献,搜索用时 15 毫秒
1.
The synthesis of new compounds based on CeO2-PrO2-La2O3, which can be used as pigments for colouring of ceramic glazes, is investigated in our laboratory. The optimum conditions
for the syntheses of these compounds have been estimated. The first information about the temperature region of the formation
of the pigments investigated is provided by thermal analysis. The synthesis of these compounds is followed by thermal analysis
using STA 449/C Jupiter (Netzsch, Germany).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
The synthesis of new compounds based on Bi2O3
is investigated because they can be used as new environmentally friendly inorganic
pigments. Chemical compounds of the (Bi2O3)1–x(Er2O3)x type were synthetized.
The host lattice of these pigments is Bi2O3 that is doped by Er3+
ions. The incorporation of doped ions provides interesting colours and contributes
to an increase in the thermal stability of these compounds. The simultaneous
TG-DTA measurements were used for determination of the temperature region
of the pigment formation and thermal stability of pigments. 相似文献
3.
V. Balek N. Todorova C. Trapalis V. Štengl E. Večerníková J. Šubrt Z. Malek G. Kordas 《Journal of Thermal Analysis and Calorimetry》2005,80(2):503-509
Summary Titania-based photocatalytic materials were prepared by sol-gel method using Fe3+ and polyethyleneglycol (PEG600) as additives. Thermogravimetry (TG), differential thermal analysis (DTA) and evolved gas analysis (EGA) with MS detection were used to elucidate processes that take place during heating of Fe3+ containing titania gels. The microstructure development of the Fe2O3/TiO2 gel samples with and without PEG600 admixtures was characterized by emanation thermal analysis (ETA) under in situ heating in air. A mathematical model was used for the evaluation of ETA results. Surface area and porosity measurements of the samples dried at 120°C and the samples preheated for 1 h to 300 and 500°C were compared. From the XRD measurements it was confirmed that the crystallization of anatase took place after thermal heating up to 600°C. 相似文献
4.
Camila S. Xavier R. A. Candeia M. I. B. Bernardi S. J. G. Lima E. Longo C. A. Paskocimas L. E. B. Soledade A. G. Souza Iêda M. G. Santos 《Journal of Thermal Analysis and Calorimetry》2007,87(3):709-713
Magnesium and zinc ferrites
have been prepared by the polymeric precursor method. The organic material
decomposition was studied by thermogravimetry (TG) and differential thermal
analysis (DTA). The variation of crystalline phases and particle morphology
with calcination temperature were investigated using X-ray diffraction (XRD)
and scanning electronic microscopy (SEM), respectively. The colors of the
ferrites were evaluated using colorimetry. Magnesium ferrite crystallizes
above 800°C, presenting a yellow- orange color with a reflectance peak
at the 600–650 nm range, while zinc ferrite crystallizes at 600°C,
with a reflectance peak between 650–700 nm, corresponding to the red-brick
color. 相似文献
5.
Fe3O4 nanorods and Fe2O3 nanowires have been synthesized through a simple thermal oxide reaction of Fe with C2H2O4 solution at 200–600°C for 1 h in the air. The morphology and structure of Fe3O4 nanorods and Fe2O3 nanowires were detected with powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy.
The influence of temperature on the morphology development was experimentally investigated. The results show that the polycrystals
Fe3O4 nanorods with cubic structure and the average diameter of 0.5–0.8 μm grow after reaction at 200–500°C for 1 h in the air.
When the temperature was 600°C, the samples completely became Fe2O3 nanowires with hexagonal structure. It was found that C2H2O4 molecules had a significant effect on the formation of Fe3O4 nanorods. A possible mechanism was also proposed to account for the growth of these Fe3O4 nanorods.
Supported by the Fund of Weinan Teacher’s University (Grant No. 08YKZ008), the National Natural Science Foundation of China
(Grant No. 20573072) and the Doctoral Fund of Ministry of Education of China (Grant No. 20060718010) 相似文献
6.
Danniely S. de Melo M. R. C. Santos Iêda M. G. Santos L. E. B. Soledade M. I. B. Bernardi E. Longo A. G. Souza 《Journal of Thermal Analysis and Calorimetry》2007,87(3):697-701
SnO2-based
materials are used as sensors, catalysts and in electro–optical devices.
This work aims to synthesize and characterize the SnO2/Sb2O3-based
inorganic pigments, obtained by the polymeric precursor method, also known
as Pechini method (based on the metallic citrate polymerization by means of
ethylene glycol). The precursors were characterized by thermogravimetry (TG)
and differential thermal analysis (DTA). After characterization, the precursors
were heat-treated at different temperatures and characterized by X-ray diffraction.
According to the TG/DTA curves basically two-step mass loss process was observed:
the first one is related to the dehydration of the system; and the second
one is representative to the combustion of the organic matter. Increase of
the heat treatment temperature from 500 to 600°C and 700°C resulted
higher crystallinity of the formed product. 相似文献
7.
Irena Szczygieł Aleksandra Matraszek Teresa Znamierowska 《Journal of Thermal Analysis and Calorimetry》2008,93(3):671-676
Ce2O3-K2O-P2O5 ternary system has been investigated by thermoanalytical methods (DTA, DSC), powder X-ray diffraction, XPS and IR spectroscopy.
The existence of three double potassium-cerium(III) phosphates has been confirmed and a new binary phosphate K4Ce2P4O15 has been found. Phase diagram and isothermal section at room temperature of the system Ce2O3-K2O-P2O5 have been presented. 相似文献
8.
Žaneta Dohnalová Petra Šulcová M. Trojan 《Journal of Thermal Analysis and Calorimetry》2008,91(2):559-563
This work is focused on determination of the optimum firing temperature which leads to formation of the compounds LnFeO3 with good pigment-application properties (Ln=Gd, La, Yb, Tm, Lu). Based on results of thermal analysis the compounds were prepared by the solid-state reaction at temperature
900 and 1000°C. Colours of pigments vary depending on type of used lanthanoid (from light sienna to dark brown) and also on
the type of precursor. Generally, the compounds prepared from iron oxide have more interesting color properties. Colour of
these compounds is brighter and deeper. Increasing of the calcination temperature from 900 to 1000°C causes the darkening
of colour. The most problably, the darkening is connected with partial reduction of Fe3+ to Fe2+. 相似文献
9.
The processes of nucleation of Li2O-Al2O3-SiO2 glasses with TiO2 and TiO2+ZrO2 as nucleating agents were discussed. The DTA peak temperature and DTA peak height shown a strong dependence on the nucleation temperature in the glass with TiO2, while in the glass with TiO2+ZrO2 this tendency was small. The optimum nucleation temperatures were 745 and 760°C for two glasses. It suggested that with TiO2+ZrO2 as nucleating agents, the crystallization had lower sensitivity for nucleation temperature, and the glass had higher nucleation efficiency than with TiO2. 相似文献
10.
11.
The conductivity and transport number of oxygen ions of Bi2O3-(10, 30, 50) vol % NiO composites are measured using the four-probe and coulomb-volumetric methods at various temperatures. It is shown that the Bi2O3-50 vol % NiO composite exhibits a high mixed ionic-electronic conductivity in the temperature range from 730 to 800°C. 相似文献
12.
F. Chehimi-Moumen P. Llewellyn F. Rouquerol G. Vacquier D. Ben Hassen-Chehimi M. Ferid M. Trabelsi-Ayadi 《Journal of Thermal Analysis and Calorimetry》2005,82(3):783-789
Summary The aim of this work is the optimization of the preparation of anhydrous gadolinium hydrogen phosphate with good fluorescence
properties. The products obtained by dehydration of gadolinium hydrogen phosphate trihydrate depend on the conditions chosen
for the thermal treatment. For this reason, the dehydration was followed by Constant Rate Thermal Analysis whilst strictly
controlling the water vapour pressure above the sample. Intermediate samples, obtained during dehydration were characterised
by IR spectroscopy and X-ray diffraction. It has thus been shown that the thermal pathway taken for the dehydration depends
on the water vapour pressure above the sample in the region from 10-2to 5 mbar. Under the lowest water vapour pressure (5·10-3mbar), the elimination of the crystallization water is carried out in a continuous way and produces a quasi-amorphous intermediate.
Under higher water vapour pressure (5 mbar), well crystallized intermediate products are obtained. The results obtained suggest
that the trihydrate contains zeolitic water which confirms a prior structural study. 相似文献
13.
2CaO·3B2O3·H2O which has non-linear optical (NLO) property was synthesized under hydrothermal condition and identified by XRD, FTIR and
TG as well as by chemical analysis. The molar enthalpy of solution of 2CaO·3B2O3·H2O in HCl·54.572H2O was determined. From a combination of this result with measured enthalpies of solution of H3BO3 in HCl·54.501H2O and of CaO in (HCl+H3BO3) solution, together with the standard molar enthalpies of formation of CaO(s), H3BO3(s), and H2O(l), the standard molar enthalpy of formation of −(5733.7±5.2) kJ mol−1 of 2CaO·3B2O3·H2O was obtained. Thermodynamic properties of this compound were also calculated by a group contribution method. 相似文献
14.
The synthesis of new compounds based on Bi2O3 is investigated because they can be used as new colour inorganic pigments. Chemical compounds of the Bi2-xYx/2Zr3x/8O3 type were synthetised. The host lattice of these pigments is Bi2O3 that is doped by Y3+ and Zr4+ ions. The incorporation of doped ions provides interesting colours and contributes to a growth of the thermal stability of
these compounds. The simultaneous TG-DTA measurements were used for determination of the temperature region of the pigment
formation and thermal stability of pigments. This paper also contains the results of the pigment characterization by X-ray
powder diffraction and their colour properties. 相似文献
15.
The synthesis of new compounds based on Bi2O3 is investigated because they can be used as new ecological inorganic pigments. Chemical compounds of the Bi2−xErx/2Zr3x/8O3 type were synthetized. The host lattice of these pigments is Bi2O3 that is doped by Er3+ and Zr4+ ions. The incorporation of doped ions provides interesting colours and contributes to a growth of the thermal stability of
these compounds. The simultaneous TG-DTA measurements were used for determination of the temperature region of the pigment
formation and thermal stability of pigments. This paper also contains the results of the pigment characterization by X-ray
powder diffraction and their colour properties. 相似文献
16.
As an asymmetric organic molecular crystal, p-N,N-dimethylaminobenzaldehyde (DAB) exhibits peculiar optical property. It was first grown by solution technique adopting slow
evaporation method at room temperature using CCl4 as growth medium. The solubility of DAB increases with temperature. Good quality transparent crystals of p-N,N-dimethylaminobenzaldehyde were carefully collected and subjected various characterization studies such as UV, FTIR, 1H and 13CNMR spectral studies and thermal (TG-DTG) studies to determine the purity and application oriented properties of the grown
crystals. 相似文献
17.
Differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) were used to study the thermal behaviour of (50-x)Na2O-xTiO2-50P2O5 and 45Na2O-yTiO2-(55-y)P2O5 glasses. The addition of TiO2 to the starting glasses (x=0 and y=5 mol% TiO2) resulted in a nonlinear increase of glass transition temperature and dilatation softening temperature, whereas the thermal
expansion coefficient decreased. All prepared glasses crystallize under heating within the temperature range of 300–610°C.
The contribution of the surface crystallization mechanism over the internal one increases with increasing TiO2 content. With increasing TiO2 content the temperature of maximum nucleation rate is also gradually shifted from a value close to the glass transition temperature
towards the crystallization temperature. X-ray diffraction measurements showed that the major compounds formed by glass crystallization
were NaPO3, TiP2O7 and NaTi2(PO4)3. The chemical durability of the glasses without titanium oxide is very poor, but with the replacement of Na2O or P2O5 by TiO2, it increases sharply. 相似文献
18.
The synthesis of new pigments based on Bi2O3
is investigated because they give interesting orange hues and can substitute
the pigments problematic from the environmental point of view. Chemical compounds
of the Bi2–xZr3x/4O3
type were synthesized. The host lattice of these pigments is Bi2O3
that is doped by Zr4+ ions. The area of ZrO2
solubility in Bi2O3 at 800°C
forming solid solution of both oxides was studied. The incorporation of doped
ions provides interesting colours and contributes to a growth of the thermal
stability of these compounds. The simultaneous TG-DTA measurements were used
for determination of the temperature region of the pigment formation and thermal
stability of pigments. 相似文献
19.
The synthesis of new compounds based on the Bi2O3–Ho2O3 system, which can be used as new ecological inorganic
pigments, is investigated in our laboratory. The optimum conditions for the
syntheses of these compounds have been followed by the methods of thermal
analysis that can provide first information about the temperature region of
the pigment formation. The synthesis of these compounds was followed by thermal
analysis using STA 449/C Jupiter (Netzsch, Germany). 相似文献
20.
L. A. Klinkova V. I. Nikolaichik N. V. Barkovskii V. K. Fedotov 《Russian Journal of Inorganic Chemistry》2007,52(12):1822-1829
Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) of an α-Bi2O3 sample revealed staged phase transitions in the range 720–800°C (at 720, 780, and 800°C) and the elimination of oxygen to the composition Bi2O2.967 during heating to 895°C in air at 16 K/min. In dynamic vacuum (p = 1.33 Pa) at 780–800°C, Bi2O3 consecutively transforms to a phase with the cubic γ-Bi2O3 structure and tetragonal Bi2O2.3?2.4. In the latter, electron diffraction in a transmission electron microscope (ED/TEM) shows a superstructure with the superstructure vector q 110 ≈ 1/9, which indicates an ordered arrangement of oxygen vacancies. 相似文献