Synthesis, Characterization and Thermal Stability of Highly Crystallized Titania Nanotubes

2004 ◽  
Vol 836 ◽  
Author(s):  
B. Poudel ◽  
W. Z. Wang ◽  
C. Dames ◽  
J. Y. Huang ◽  
S. Kunwar ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hydrothermal Method ◽  
Phase Stability ◽  
Acid Treatment ◽  
Filling Fraction ◽  
Volume Filling ◽  
Synthesis Conditions ◽  
Outside Diameter ◽  
Thermal Stability Of ◽  
Crystallization Structure

ABSTRACTGram quantities of titania (TiO2) nanotubes, with typical outside diameter about 9 nm, wall thickness about 2.5 nm, and length about 600 nm, were synthesized from anatase nano- and micro-powder using the hydrothermal method. The crystallization, structure, and phase stability of the nanotubes at high temperatures were systematically studied. A morphology change from nanotube to nanowire was observed at 650°C. The as-prepared nanotubes were usually contaminated with sodium impurities, other TiO2-derived phases and were poorly crystallized, but under optimized synthesis conditions the impurity phases was completely removed, resulting in highly crystallized pure nanotubes. The volume filling fraction of the autoclave as well as the concentration of the acid treatment were found to be particularly important for controlling the purity and crystallinity of the resulting nanotubes.

Thermal stability of tetrabutyl-phosphonium and -ammonium exchanged montmorillonite: Influence of acid treatment

2017 ◽  
Vol 138 ◽  
pp. 63-73 ◽  
Author(s):  
Helena Pálková ◽  
Małgorzata Zimowska ◽  
Ľuboš Jankovič ◽  
Bogdan Sulikowski ◽  
Ewa M. Serwicka ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Acid Treatment ◽  
Thermal Stability Of

Strontium Hydroxyapatite Synthesis, Characterization and Cell Cytotoxicity

2010 ◽  
Vol 160-162 ◽  
pp. 117-122 ◽  
Author(s):  
Zhi Hong Li ◽  
Ji Min Wu ◽  
Shu Jie Huang ◽  
J. Guan ◽  
Xi Zheng Zhang
Keyword(s):  
Thermal Stability ◽  
Hydrothermal Method ◽  
Bone Repair ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strontium Hydroxyapatite ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Phase Chemical

Strontium hydroxyapatite powders was prepared by the hydrothermal method using Sr(NO3)2 and (NH4)2HPO4 as reagents. Fourier transform infrared spectroscopy, X-ray diffraction, Transmission electron microscope, Energy dispersive X-ray, and Thermogravimetric-differential thermal analysis were employed to investigate the crystalline phase, chemical composition, morphology, and thermal stability of the Strontium hydroxyapatite. And the cytotoxicity of Strontium hydroxyapatite was analyzed through MTT assay. Results showed that Strontium hydroxyapatite prepared by hydrothermal Method has excellent crystal structure, good dispersion, high purity, and rod-like morphology with dimensions 200-500 nm in length and 20 nm in diameter. Meanwhile, the apatite has poor thermal stability. However, the apatite is cytocompatible and may have better biocompatibility, which can serve as strontium source incorporation into calcium phosphate cement and for bone repair.

scholarly journals Thermal stability of self-polarization in a (K,Na)NbO3 film prepared by the hydrothermal method

2021 ◽  
Author(s):  
Akinori Tateyama ◽  
Yoshiharu Ito ◽  
Takahisa Shiraishi ◽  
Yuichiro Orino ◽  
Minoru Kuribayashi KUROSAWA ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hydrothermal Method ◽  
Thermal Stability Of

Phase Stability in the Al(6−x)CuxZr2 System for 0 < × < 1.

1990 ◽  
Vol 186 ◽  
Author(s):  
P. B. Desch ◽  
R. B. Schwarz ◽  
P. Nash
Keyword(s):  
Thermal Stability ◽  
Phase Stability ◽  
Single Phase ◽  
Lattice Parameter ◽  
Elemental Powder ◽  
Mechanically Alloyed ◽  
Two Phase ◽  
Powder Mixtures ◽  
Phase Mixture ◽  
Thermal Stability Of

AbstractWe have determined the structures and thermal stability of AI(6-x) CuxZr2 (0≤ × ≤ 1) powders prepared by mechanically alloying elemental powder mixtures. In the as mechanically alloyed condition the structure is L12 for all ×. After heating to 750°C the alloy is single phase D023 for 0 < × < 0.2, is a two-phase mixture of D023 and L12 for 0.2 < × < 0.6, and remains in the Ll2 phase for 0.6 < × < 1. Al5CuZr2 is stable in the Ll2 structure up to 1300°C. The lattice parameter of the annealed L12 phase is Independent of ×.

Preparation and Electrical Conductivity of Polythiophene/Microcrystal Muscovite Layered Composites

2015 ◽  
Vol 814 ◽  
pp. 392-397 ◽  
Author(s):  
Ying Ling ◽  
Jian Ping Long
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Composite Materials ◽  
Reaction Time ◽  
Layered Composites ◽  
Synthesis Conditions ◽  
Conductive Composites ◽  
Monomer Ratio ◽  
Thermal Stability Of ◽  
Oxidation System

Polythiophene(PTP)/microcrystal muscovite conductive composites were prepared by the method of intercalating polymerization via Fe3+-H2O2 catalytic oxidation system in water. The morphology, structures, electrical conductivity and thermal stability of composites have been studied preliminary. The influence of the different synthesis conditions (temperature, monomer ratio, reaction time) on the conductivity of composite materials was explored. The results of the FTIR and XRD confirmed that thiophene (TP) inserted into the layers of microcrystal muscovite to polymerize and formed intercalation compounds. TG analysis indicated the improved thermostability of composite materials. The PTP/microcrystal muscovite composite made from 2g/ml solution of microcrystal muscovite/TP with reacting for 12h and 15°C showed the highest conductivity 3.56 ×10-5s/cm-1.

Synthesis and Thermal Stability of One-Dimensional Titanate Nanotubes

2009 ◽  
Vol 79-82 ◽  
pp. 433-436 ◽  
Author(s):  
Lei Zhong ◽  
Yue Li Liu ◽  
Wei Shu ◽  
Yan Bao Song ◽  
Wen Chen
Keyword(s):  
Thermal Stability ◽  
Phase Transformations ◽  
Hydrothermal Method ◽  
Thermal Stabilization ◽  
Titanate Nanotubes ◽  
Rutile Tio2 ◽  
Simple Hydrothermal Method ◽  
One Dimensional ◽  
Tio2 Nanobelts ◽  
Thermal Stability Of

In the present work, a novel titanate (H2Ti5O11•3H2O) nanotubes are synthesized by a simple hydrothermal method, and their thermal stability such as the phase transformations and microstructures change are also studied. The as-grown samples are heated in the air at 300-800 °C. The titanate nanotubes will be completely destroyed when the temperatures are above 600 °C, which show that the present titanate nanotubes possess good thermal stabilization. The experiment results reveal that the phase transformations and microstructure changes of present titanate nanotubes follow the process from titanate nanotubes to anatase and rutile TiO2 nanobelts, the Na2Ti6O13 nanwires are formed over 700 °C.

Study on spinning stability and microstructure of mesophase pitch

2020 ◽  
Vol 10 (10) ◽  
pp. 1711-1717
Author(s):  
Shi-Lin Chen ◽  
Zhi-Cheng Ma ◽  
Chang-Ling Fan ◽  
Yu-Lin Liang ◽  
Chong Ye
Keyword(s):  
Thermal Stability ◽  
Phase Separation ◽  
Phase Stability ◽  
Mesophase Pitch ◽  
Isotropic Phase ◽  
Study Results ◽  
Spinning Process ◽  
Local Enrichment ◽  
Thermal Stability Of

The effect of spinning temperature on phase stability, rheological stability, and thermal stability of mesophase pitch (MP), naphthalene-based mesophase pitch (AR) and microstructure of pitch filament were investigated in this study. Results showed that the interface stratification of anisotropic and isotropic phases, local enrichment of isotropic phases and extensive enrichment of isotropic phases existed in the spinning process for mesophase pitch. The local enrichment of isotropic phase was observed in MP and AR at the spinning temperature of 320 °C. The interface stratification of anisotropic and isotropic phases and extensive enrichment of isotropic phases were generated in MP when the spinning temperature reached 340 °C. This phase separation reduced the rheological stability and thermal stability of mesophase pitch and then affected the spinning ability. The inhomogeneous pores were also formed in the MP and AR mesophase pitch filament at the spinning temperature of 340 °C.

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