scholarly journals Preparation and characterization of magnetite-based silica nanocomposite

2004 ◽  
pp. 121-129 ◽  
Author(s):  
Mihaela Popovici ◽  
Cecilia Savii ◽  
Daniel Niznanský ◽  
Jan Subrt ◽  
Eva Vecernikova ◽  
...  
Keyword(s):  
Thermal Analyses ◽  
Sol Gel ◽  
Nitrogen Atmosphere ◽  
Thermal Treatments ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Phase

Sol-gel method and successive thermal treatments in vacuum and nitrogen atmosphere were employed to synthesize magnetite nanoparticles isolate them with the aid of amorphous silica. Thermogravimetric and differential thermal analyses coupled with mass spectrometry, X-ray diffraction, transmission electron microscopy, M?ssbauer spectroscopy and vibrating sample magnetometry measurements were performed on the obtained nanocomposites. The effect of atmosphere on the formation of magnetite phase was remarkable.

Sol-Gel Synthesis and Characterization of Nanocrystalline Bi4Ti3O12 Powders

2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan
Keyword(s):  
Phase Inversion ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis ◽  
Source Materials

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.

Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

1997 ◽  
Vol 12 (3) ◽  
pp. 596-599 ◽  
Author(s):  
Ji Zhou ◽  
Qing-Xin Su ◽  
K. M. Moulding ◽  
D. J. Barber
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

Comparative Study of Properties of Cellulose Nanofibers From Wheat Straw Obtained by Chemical and Chemi-Mechanical Treatments

2014 ◽  
Author(s):  
Md. Nuruddin ◽  
Mahesh Hosur ◽  
Eldon Triggs ◽  
Shaik Jeelani
Keyword(s):  
Wheat Straw ◽  
Thermal Analyses ◽  
Cellulose Nanofibers ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Scanning Electron Micrograph ◽  
X Ray ◽  
Isolation Techniques ◽  
Transmission Electron

Objective of this work was to compare morphology, crystalline and thermal properties of cellulose nano fibers derived from wheat straw by two different processes (ball milling and acid hydrolysis treatment). The characterization of extracted CNFs was done by Scanning electron micrograph (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). It was found from morphological, crystalline and thermal analyses that isolated cellulose nanofibers have diameter of nano meter ranges (10–25 nm), 68–80 % crystallinity and decomposition temperature of around 284–353° C, depending upon isolation techniques.

Synthesis and Characterization of MgPSZ-PMMA Composite by Sol-Gel Modification and Direct Foaming Technique Using Egg Whites

2016 ◽  
Vol 720 ◽  
pp. 290-295
Author(s):  
Veni Takarini ◽  
Alfend Rudyawan ◽  
Andri Hardiansyah ◽  
Rifki Septawendar ◽  
Niki Prastomo ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Crystal Size ◽  
Sol Gel ◽  
Porous Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Direct Foaming ◽  
Transmission Electron ◽  
Direct Foaming Method

This study prepared Magnesium-Partially Stabilized Zirconia (Mg-PSZ) filler synthesis and direct foaming technique using egg whites, and impregnated by PMMA. The results were evaluated systematically by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). XRD results denote that the powder sample of MgPSZ was successfully formed with various crystal size of tetragonal and monoclinic phase. SEM and TEM observations revealed that nanoparticles MgPSZ were in spherical and long rounded shapes. Furthermore, SEM observation revealed that the direct foaming method were also successful in the formation of porous structures which favourable for impregnation process by PMMA. The use of egg whites as a polymer precursor in both methods demonstrates that porous specimens contained nanosized, predominantly tetragonal, Mg-PSZ powders were successfully synthesized. This shall yield an interesting prospect towards cheap, reliable, and biocompatible product to resemble the modulus elasticity of dentin.

Characterization of Y/TiO2 Nanoparticles and their Reactivity for CO2 Photoreduction

2011 ◽  
Vol 55-57 ◽  
pp. 1506-1510 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
Transmission Electron ◽  
And Chemical Properties

A series of Y/TiO2nanoparticles (NPs) were synthesized via sol-gel method. The crystal structures, morphologies and chemical properties were characterized using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). We investigated the effects of different doping amounts of Y on the reaction of CO2photoreduction. The results shown that 0.1 wt.%Y/TiO2(0.1YT) performed the highest photocatalytic activity, which yielded 384.62 µmol/g∙cat. formaldehyde after 6 h of UV illumination.

scholarly journals Fabrikasi Nanotubes Titanium Dioksida (TiO2) Menggunakan Metode Hidrotermal

2017 ◽  
Vol 3 (1) ◽  
pp. 20-26
Author(s):  
Atik Setyani ◽  
Emas Agus Prastyo Wibowo
Keyword(s):  
Tio2 Nanoparticles ◽  
Tio2 Nanotubes ◽  
Crystal Size ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Nanotubes received great attention because it has a high surface area. In this study, TiO2 nanotubes fabricated via hydrothermal method from  synthesis of TiO2 nanoparticles via sol-gel method. Catalysts that have been synthesized later in the characterization by X-Ray Diffraction (XRD) to obtain the crystal size and crystallinity. Crystal size of TiO2 nanoparticles at a temperature of 450C is 13.78 nm. Then characterized by Transmission Electron Microscopy (TEM) to look at the formation of nanotubes. Characterization of TiO2 nanotubes with TEM shows that the structure of the tubes had already been formed TNTs although the growth has not been perfect. It can be seen from the structure TNTs who tend to be short and yet so irregular.DOI: http://dx.doi.org/10.15408/jkv.v0i0.5036  

scholarly journals Fabrication and characterization of ferrites (Mg and Mn) based on FTIR, XRD, SEM and TEM

2014 ◽  
Vol 8 (3) ◽  
Author(s):  
Tang Ing Hua ◽  
Rita Sundari
Keyword(s):  
Electron Microscope ◽  
Volume Expansion ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Semiconducting Materials ◽  
Thermal Agitation ◽  
X Ray ◽  
Transmission Electron ◽  
Fabrication And Characterization

This study has encountered with the fabrication of ferrites (Mg and Mn) using citric acid as anionic surfactant in sol-gel method followed by calcinations at varied temperatures (300, 600, 800°C) for 2h, respectively. The fabricated ferrites have been characterized by FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffraction), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). The FTIR spectrum for MnFeO3 shows that some functional groups already removed under 300°C calcination due to several oxidation numbers possessed by Mn leading to more flexibility. The XRD diffractograms for both MgFe2O4 and MnFeO3 show that the transition phase from amorphous to crystalline structure occurred in the temperature range of 300-600°C. The SEM mappings based on the Fe distribution for both MgFe2O4 and MnFeO3 show that more Fe distributed over the ferrites surface at 600 and 800°C, while the SEM mappings for both ferrites (Mg and Mn) show less Fe distribution at 300°C calcination, thus, it indicates more repulsion force bearing by higher amounts of Fe atoms at higher thermal agitation due to volume expansion. The TEM spectra proved that both ferrites existed as crystals after calcined at 600°C. The fabricated ferrites have remarkable electrical properties useful for the manufacture of semiconducting materials.

scholarly journals Obtaining and Characterization of TiO2-GO Composites for Photocatalytic Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
D. K. Calvo Ramos ◽  
M. Vega González ◽  
R. A. Esparza Muñóz ◽  
J. Santos Cruz ◽  
F. J. De Moure-Flores ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Uv Radiation ◽  
Uv Light ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

Titanium dioxide (TD) and graphene oxide (GO) were synthesized by sol-gel and improved Hummers method, respectively. This study shows the results of the incorporation through four different conditions (sol-gel, sol-gel and ultrasonic, annealed, and UV radiation, C1 to C4, respectively). It was observed that a homogeneous incorporation of TD on sheets of GO was obtained satisfactorily. The composites of TiO2/GO were characterized using different techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, and infrared spectroscopy (IR). The photocatalytic activity of the composites was determined from the degradation of the dye azo tartrazine using UV and solar radiation. The best incorporation of TD nanoparticles on GO was obtained with condition C3 (thermal incorporation method) at a temperature of 65°C. This shows a uniformity in the size and shape of the TD as well as an excellent adherence to the sheet of GO. This addition is accomplished by ionic bonding in the presence of electrostatic Coulomb forces. The C3 composite degraded the tartrazine dye using UV radiation and sunlight. With the latter, the degradation time was three times faster than using UV light.

scholarly journals Preparation and Characterization of Novel Mixed Periodic Mesoporous Organosilica Nanoparticles

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1569
Author(s):  
Hao Li ◽  
Laurence Raehm ◽  
Clarence Charnay ◽  
Jean-Olivier Durand ◽  
Roser Pleixats
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Periodic Mesoporous Organosilica ◽  
X Ray ◽  
Surface Areas ◽  
Mesoporous Organosilica ◽  
Transmission Electron ◽  
Cp Mas Nmr

We report herein the preparation of mixed periodic mesoporous organosilica nanoparticles (E-Pn 75/25 and 90/10 PMO NPs) by sol-gel co-condensation of E-1,2-bis(triethoxysilyl)ethylene ((E)-BTSE or E) with previously synthesized disilylated tert-butyl 3,5-dialkoxybenzoates bearing either sulfide (precursor P1) or carbamate (precursor P2) functionalities in the linker. The syntheses were performed with cetyltrimethylammonium bromide (CTAB) as template in the presence of sodium hydroxide in water at 80 °C. The nanomaterials have been characterized by Transmission Electron Microscopy (TEM), nitrogen-sorption measurements (BET), Dynamic Light Scattering (DLS), zeta-potential, Thermogravimetric Analysis (TGA), FTIR, 13C CP MAS NMR and small angle X-ray diffraction (p-XRD). All the nanomaterials were obtained as mesoporous rodlike-shape nanoparticles. Remarkably, E-Pn 90/10 PMO NPs presented high specific surface areas ranging from 700 to 970 m2g−1, comparable or even higher than pure E PMO nanorods. Moreover, XRD analyses showed an organized porosity for E-P1 90/10 PMO NPs typical for a hexagonal 2D symmetry. The other materials showed a worm-like mesoporosity.

scholarly journals Characterization of Enhanced Antibacterial Effects of Silver Loaded Cerium Oxide Catalyst

2018 ◽  
Vol 34 (6) ◽  
pp. 2895-2901
Author(s):  
Gusliani Eka Putri ◽  
Syukri Arief ◽  
Novesar Jamarun ◽  
Feni Rahayu Gusti ◽  
Annisa Novita Sary
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Sol Gel ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference

Silver-cerium nanoparticles had been successfully synthesized using the sol-gel method by silver nitrate as a source of silver and cerium nitrate hexahydrate as a source of cerium. The synthesized silver-cerium nanoparticles had been characterized by X-ray diffraction,transmission electron microscopy, and scanning electron microscopy-energy dispersive X-ray. Based on the results of XRD and TEM analysis showed silver-cerium nanoparticles were spherical with the dominant size range of 8.9 -12.73 nm. SEM-EDX analysis showed silver nanoparticles covered by cerium nanoparticles that were known as the core-shell structure. Silver nanoparticles doped with cerium nanoparticles (CeONP) showed an increase in inhibitory with an increase a zone of inhibition after being doped with cerium nanoparticles. The disinfection effect of Ag-doped CeONP was more pronounced on Staphylococcus aureus than Escherichia coli, although the difference was not wide.

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