Graphene sheets manipulated the thermal-stability of ultrasmall Pt nanoparticles supported on porous Fe2O3nanocrystals against sintering

Supported Pt nanoparticle stabilization via Atomic Layer Deposition overcoating with Al2O3 has been proved to prevent particle coarsening during thermal annealing for widely spaced nanoparticles while ensuring surface accessibility for applications.

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Synthesis and thermal stability of star polymer with eight arms using polyhedral oligomeric silsesquioxane as a core

e-Polymers ◽

10.1515/epoly.2010.10.1.1587 ◽

2010 ◽

Vol 10 (1) ◽

Author(s):

Lei Liu ◽

Wenping Wang ◽

Xianran Guo

Keyword(s):

Thermal Stability ◽

Polyhedral Oligomeric Silsesquioxane ◽

Catalyst System ◽

Star Polymer ◽

Good Thermal Stability ◽

Methyl Methacrylates ◽

Oligomeric Silsesquioxane ◽

Polymerization Method ◽

Form Star ◽

Thermal Stability Of

AbstractA Polyhedral oligomeric silsesquioxane (POSS) containing eight 3- chloropropyl groups was synthesized and incorporated into poly(methyl methacrylates) to form star polymer. First, octa(3-chloropropyl) POSS [(ClCH2CH2CH2)8Si8O12] was prepared by hydrolysis and condensation of 3- chloropropyltriethoxysilane, and then two star-shaped POSS/PMMA composites with different POSS content was synthesized at 110 °C, using octa(3-chloropropyl) POSS as an multifunctional initiator, CuCl and 2-2’ bipyridine (Bpy) as catalyst system. The structures of octa(3-chloropropyl) POSS and star-shaped POSS/PMMA composite were characterized by analytical methods including FTIR, NMR, GPC and XRD, with results showing that POSS molecule was successfully formed which accorded well with the reported work and was dispersed into PMMA matrix evenly by atom transfer radical polymerization method. The TGA results indicated that synthetic POSS molecule possessed good thermal stability, and the thermal stability of POSS/PMMA composite enhanced with the increase of POSS content, which is due to the incorporation of inorganic POSS molecule

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Morphology of Multi-Walled Carbon Nanotubes Affected by the Thermal Stability of the Catalyst System

Chemistry of Materials ◽

10.1021/cm062237l ◽

2007 ◽

Vol 19 (2) ◽

pp. 179-184 ◽

Cited By ~ 54

Author(s):

E. Dervishi ◽

Z. Li ◽

A. R. Biris ◽

D. Lupu ◽

S. Trigwell ◽

...

Keyword(s):

Carbon Nanotubes ◽

Thermal Stability ◽

Catalyst System ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Thermal Stability Of

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A Novel Nonlocal Four Variable Plate Theory for Thermal Stability of Single- layered Graphene Sheets Embedded in An Elastic Substrate Medium

Current Nanomaterials ◽

10.2174/2405461501666161130121643 ◽

2017 ◽

Vol 1 (3) ◽

pp. 215-222 ◽

Cited By ~ 2

Author(s):

Fouzia Krenich ◽

Houari Heireche ◽

Mohammed S.A. Houari ◽

Abdelouahed Tounsi

Keyword(s):

Thermal Stability ◽

Plate Theory ◽

Graphene Sheets ◽

Elastic Substrate ◽

Substrate Medium ◽

Thermal Stability Of

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Thermal Stability of Pt Nanoparticles Supported on WOx/Al2O3 for n-Heptane Hydroconversion

MRS Proceedings ◽

10.1557/proc-1279-31 ◽

2010 ◽

Vol 1279 ◽

Author(s):

J. L. Contreras ◽

G.A. Fuentes ◽

J. Salmones ◽

B. Zeifert

Keyword(s):

Thermal Stability ◽

Bimetallic Catalysts ◽

Pt Nanoparticles ◽

Thermal Stabilization ◽

Reaction Rates ◽

Atomic Ratio ◽

Impregnation Method ◽

Reduction Temperature ◽

Sequential Samples ◽

Thermal Stability Of

AbstractThe thermal stabilization of γ-Al2O3 using W+6 ions has been found useful to the synthesis of Pt/Al2O3 catalysts. The sequential impregnation method was used to study the effect of W6+ upon Pt/ γ-Al2O3 reducibility, Pt dispersion, Raman spectroscopy and n-heptane hydroconversion. The W/Pt atomic ratios varied from 3.28 to 75. We found that the W6+ ions delayed reduction of a fraction of Pt+4 atoms beyond 773 K. At the same time, W6+inhibited sintering of the metallic crystallites once they were formed on the surface. For the sample with a W/Pt atomic ratio of 3.28, W6+ did not inhibit the H2 reduction of Pt oxides even below of 773 K, the Pt oxides were reduced completely, however, the Pt dispersion decreased for this sample with respect to the Pt/γ-Al2O3 catalyst. After reduction at 1073 K, sequential samples impregnating Pt on WOx/γAl2O3 were more active and stable during n-heptane hydroconversion than monometallic Pt/γAl2O3 catalyst. Selectivities for dehydrocyclization, isomerization and Hydrocracking changed significantly when the W/Pt atomic ratio and reduction temperature increased. Initial and final reaction rates were more sensitive to reduction temperature. W6+ ions promoted high thermal stability of Pt crystallites when sequential catalysts were reduced at 1073 K and deactivation of bimetallic catalysts reduced at 773 K and 1073 K was less than the deactivation of Pt/Al2O3 catalyst.

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The Ordered Phase Formation in Ti-Al-Ga Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069193 ◽

1970 ◽

Vol 28 ◽

pp. 440-441

Author(s):

Shiro Fujishiro ◽

Harold L. Gegel

Keyword(s):

Thermal Stability ◽

High Temperature ◽

Titanium Alloys ◽

Growth Kinetics ◽

Stoichiometric Composition ◽

Good Potential ◽

Alpha Titanium ◽

Cold Rolled ◽

Kinetics Of ◽

Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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Microstructure studies of tungsten silicide schottky contacts on Gaas

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126445 ◽

1987 ◽

Vol 45 ◽

pp. 328-329

Author(s):

Yih-Cheng Shih ◽

E. L. Wilkie

Keyword(s):

Thermal Stability ◽

Field Effect Transistors ◽

Schottky Contact ◽

Schottky Contacts ◽

Excellent Thermal Stability ◽

Barrier Heights ◽

Gaas Substrates ◽

Film Adhesion ◽

Threshold Voltages ◽

Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

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