Crystalline phases of sol-gel ZrO2 in the ZrO2-SiO2 system: Differential thermal analysis and electron microscopy studies

1995 ◽  
Vol 10 (6) ◽  
pp. 1397-1402 ◽  
Author(s):  
D.R. Acosta ◽  
O. Novaro ◽  
T. López ◽  
R. Gómez
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Zirconium Oxide ◽  
Sol Gel ◽  
Thermal Treatments ◽  
Crystalline Phases ◽  
Preparation Conditions ◽  
Zirconium Acetate

Zirconium oxide dispersed in silica was synthesized by the cogelation of tetraethoxysilane and zirconium acetate. For the gelation, acid and basic media were used. The final zirconia concentration was around 6.7 wt. %. Differential thermal analysis, thermogravimetric analysis, as well as electron microscope techniques were used for the characterization of the samples. It was found that the stabilization of the crystalline phases depends on the preparation conditions and thermal treatments. Tetragonal and monoclinic ZrO2 phases were identified in basic preparations. However, in acidic samples only low-temperature tetragonal phase was identified.

Synthesis and Characterization of Ti, Fe-Doped Mullite-I

2011 ◽  
Vol 217-218 ◽  
pp. 163-168 ◽  
Author(s):  
Lin Xin Tong ◽  
Jin Hong Li ◽  
Jian Cao
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Phase Separation ◽  
Powder Diffraction ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Formation Temperature ◽  
Gel Method ◽  
X Ray

A series of gels with 3Al2O3•2SiO2 were prepared by Sol-gel method and heated at several temperatures for 2 h to synthesize Ti, Fe-doped mullite. The powers were characterized by differential thermal analysis (DSC-TG) and X-ray powder diffraction (XRD). Phase separation was promoted by doping both TiO2 and Fe2O3; with increasing the amount of dopant ions the formation temperature of Si-Al spinel decreased and the formation temperature of mullite increased by TiO2 doping but decreased by Fe2O3 doping. The formation temperature of pure mullite was about 1250-1350 °C.

Preparation and characterization of alumina membranes and alumina–titania composite membranes

1999 ◽  
Vol 14 (9) ◽  
pp. 3599-3603 ◽  
Author(s):  
Li Shi ◽  
Ning-Bew Wong
Keyword(s):  
Thermal Analysis ◽  
Particle Size ◽  
Differential Thermal Analysis ◽  
Sol Gel ◽  
Composite Membranes ◽  
Particle Sizes ◽  
Pore Sizes ◽  
Surface Areas ◽  
Alumina Membranes

Supported and unsupported γ-alumina membranes and alumina–titania composite membranes were prepared using the sol-gel method. In the course of preparation, effects of acid concentration, type of acid, alkoxide, and binder on the particle size of the sols and pore size of the membranes were investigated by thermogravimetry and differential thermal analysis, N2 physisorption, and light scattering. It was observed that the particle sizes of all the sols had only a small affect on the pore sizes of the membranes. Qualities of the membranes were improved by addition of polyvinyl alcohol as binder to the boehmite precursor. This resulted in less critical but more controllable drying and calcining procedures. Composite membranes with different pore sizes from 3.2 to 4.8 nm and surface areas retained above 100 m2/g could be regulated by different alumina-to-titania ratios.

Monocomponent Powders and Thin Films in the Binary System SiO2–TiO2

2007 ◽  
Vol 333 ◽  
pp. 289-292
Author(s):  
Măriuca Gartner ◽  
M. Crisan ◽  
L. Predoana ◽  
Maria Zaharescu ◽  
A. Barau ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Thermal Analysis ◽  
Preparation Method ◽  
Sol Gel ◽  
Dip Coating ◽  
Morphology And Structure ◽  
Alkoxide Route ◽  
Scanning Electron

In this work, we report the sol-gel alkoxide route preparation of nanostructured SiO2 and TiO2 powders as well as TiO2-SiO2 thin films obtained by dip-coating. Thermal analysis, morphology and structure were characterized for powders and correlation between preparation method and optical properties of binary materials (SiO2-TiO2) for thin films was approached. Spectroscopic Ellipsometry (SE), Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) have been used for the physical characterization of the films.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

scholarly journals Thermal and structural characterization of the vitreous samples in the SiO2 - PbO - Na2O system

2006 ◽  
pp. 89-95 ◽  
Author(s):  
Catalina Mocioiu ◽  
Georgeta Jitianu ◽  
Maria Zaharescu
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Infrared Spectroscopy ◽  
Silicate Glasses ◽  
Lead Silicate ◽  
High Chemical ◽  
Nuclear Techniques ◽  
Infrared Data

Lead-containing glasses have been used from the ancient time. Recently, due to the possible application in optics, electronics, nuclear techniques, wastes inactivation. the interest in these types of glasses has been renewed. For lead waste inactivation, glasses with high amount of PbO in the composition are required, those exhibiting at the same time a high chemical and thermal stability. Thermal behavior of lead-silicate glasses was examined by differential thermal analysis (DTA). Infrared spectroscopy was used to investigate the structure of the glasses. The spectra were interpreted in terms of the structures of silicate group by comparison with the spectra of other silicate crystals. The DTA and infrared data were correlated with the chemical stability tests.

Preparation and Characterization of Carbon Xerogel Based Composites for Electrochemical Sensing and Photocatalytic Degradation

2021 ◽  
Vol 21 (4) ◽  
pp. 2323-2333
Author(s):  
Carmen I. Fort ◽  
Mihai M. Rusu ◽  
Lucian C. Pop ◽  
Liviu C. Cotet ◽  
Adriana Vulpoi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Electrochemical Sensors ◽  
Sol Gel ◽  
Nanocomposite Material ◽  
Electrochemical Sensing ◽  
Ambient Conditions ◽  
Carbon Xerogel ◽  
Voltammetric Detection

In order to obtain a multifunctional nanocomposite material-for electrochemical sensors and photocatalytic applications, structures based on Bi, Fe and TiO2 were grown inside carbon xerogel supports (BiFeCX and BiFeCX-TiO2). First, a wet polymer containing Bi and Fe salts was obtained by following a modified resorcinol-formaldehyde based sol–gel route, followed by drying in ambient conditions, and pyrolysis under inert atmosphere. Then, through TiCl4 hydrolysis, TiO2 nanoparticles were deposited on the BiFeCX xerogel leading to BiFeCX-TiO2. The morphological and structural characterization of the investigated nanocomposites consisted in X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and N2 adsorption measurements, revealing porous carbon structures with embedded nanoparticles and the particularities driven by the pyrolysis and TiCl4 treatment. The new modified electrodes based on BiFeCX or BiFeCX-TiO2 nanocomposite materials, kept in a chitosan matrix (Chi) and deposited on a glassy carbon (GC) electrode surface (GC/Chi-BiFeCX or GC/Chi-BiFeCX-TiO2), were obtained and investigated for Pb(II) voltammetric detection and H2O2 amperometric detection. Moreover, the BiFeCX-TiO2 nanocomposite was tested for the photocatalytic degradation of methyl orange. The great potential of BiFeCX nanocomposite material for developing electrochemical sensors, or BiFeCX-TiO2 for sensors application and photocatalytic application was demonstrated.

Purification of Bentonite Clays from Cubati, PB, Brazil, for Diversified Applications

2014 ◽  
Vol 805 ◽  
pp. 486-491
Author(s):  
J.M.R. Figueirêdo ◽  
Juliana Melo Cartaxo ◽  
I.A. Silva ◽  
C.D. Silva ◽  
Gelmires Araújo Neves ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Analysis ◽  
Laser Diffraction ◽  
The State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granulometric Analysis ◽  
Bentonite Clays

The State of Paraíba, Brazil, retains about 88.5% of all Brazilian bentonite, and much of this production comes from deposits in the District of Boa Vista, PB. Nevertheless, the deposits are almost depleted. Recently, new deposits were found, which will increases the reserves of the State, in the regions of Cubati and Pedra Lavrada, PB. The objective of this work is to characterize and develop purified clays, through sieving and hydrocycloning techniques, from those recently discovered bentonites for several applications. The characterization of the sample was done through granulometric analysis by laser diffraction, X-ray diffraction, chemical analysis by X-ray fluorescence, and thermogravimetric and differential thermal analysis. The results show that the samples are typical of bentonite clays, and that the purification solely by hydrocyclone presents the best results.

Characterization of Titanium Dioxide Nanopowder Synthesized by Sol Gel Grinding Method

2012 ◽  
Vol 626 ◽  
pp. 425-429 ◽  
Author(s):  
N.N. Hafizah ◽  
Mohamed Zahidi Musa ◽  
Mohamad Hafiz Mamat ◽  
M. Rusop
Keyword(s):  
Electron Microscopy ◽  
Anatase Phase ◽  
Sol Gel ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grinding Method ◽  
Fesem Micrographs ◽  
Scanning Electron

In this study, TiO2nanopowder was synthesized via a sol-gel grinding method. The effects of TiO2precursor concentration of TiO2nanopowder were investigated. The TiO2nanopowder obtained were characterized using X-ray diffraction (XRD), Raman spectroscopy and field emission scanning electron microscopy (FESEM) for their structural properties. From the calculation of the crystallite size in XRD, the size of the nanoparticles obtained is 49.55 nm at the highest TiO2precursor concentration. In contrast, at the lower concentration of 0.4 molar give the cryatallite size of 12.84 nm. Further, XRD and Raman spectrum results confirmed the TiO2nanopowder obtain composed of only anatase phase. The FESEM micrographs of TiO2nanopowder also were discussed in this paper.

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