Effect of Fumed Titanium Oxide on Thermal Stability of Nano-Silica Thermal Insulating Composites

2011 ◽  
Vol 284-286 ◽  
pp. 102-105
Author(s):  
Jin Peng Feng ◽  
De Ping Chen ◽  
Wen Ni ◽  
Shao Jian Ma ◽  
Jin Lin Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Titanium Oxide ◽  
X Ray Diffraction ◽  
Nano Silica ◽  
Excellent Thermal Stability ◽  
Dry Process ◽  
Thermal Insulating ◽  
Different Temperatures ◽  
Insulating Properties ◽  
Thermal Stability Of

This work investigated the effects of fumed titanium oxide on thermal stability of nano-silica thermal insulating composites prepared by dry process. The results showed that the composites could keep excellent thermal stability at the temperatures below 800°C. However, when the samples were used at higher temperatures (>800°C), the volume shrinkage increased sharply, which directly led to a serious deformation and then affected thermal insulating properties in applications. The utilization of fumed titanium oxide could significantly improve thermal stability of the composites. When 10wt% fumed titanium oxide was added, the service temperature can increase from 800°C to 900°C. The desirable results would be achieved by adjusting the amount of additives according to practical using temperature. In addition, field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) were employed to characterize the microstructure and phase transformations of the composites treated at different temperatures.

Study on Thermal Stability of Nano-Silica Thermal Insulating Composites

2012 ◽  
Vol 488-489 ◽  
pp. 588-591
Author(s):  
Jin Peng Feng ◽  
De Ping Chen ◽  
Wen Ni ◽  
Shao Jian Ma
Keyword(s):  
Thermal Stability ◽  
Fumed Silica ◽  
High Volume ◽  
High Specific Surface Area ◽  
Volume Shrinkage ◽  
Nano Silica ◽  
Excellent Thermal Stability ◽  
Thermal Insulating ◽  
Different Temperatures ◽  
Thermal Stability Of

This work investigated the thermal stability of nano-silica thermal insulating composites, which consisted of fumed silica, fibers and opacifiers. The volume shrinkage was introduced as an evaluation index to characterize thermal stability of the composites at different temperatures. The effects of serving temperature, serving time, particle size of fumed silica and mass ratio of SiC were discussed. The results indicated nano-silica thermal insulating composites have excellent thermal stability under the temperature of 800°C. The volume shrinkage was correlated positively with serving time. High specific surface area of fumed silica could bring good thermal insulating performance, but at the same time caused high volume shrinkage when applied at high temperatures. SiC as an opacifier has little influence on volume shrinkage, but too much amount may yet increase solid heat transfer and lead to the drop of thermal insulating properties.

Preparation and thermal stability of heat-resistant phenolic resin system constructed by multiple heat-resistant compositions containing boron and silicon

2016 ◽  
Vol 29 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Fengyi Wang ◽  
Zhixiong Huang ◽  
Guangwu Zhang ◽  
Yunxia Li
Keyword(s):  
Thermal Stability ◽  
Phenol Formaldehyde ◽  
Interlayer Spacing ◽  
Decomposition Temperature ◽  
Char Yield ◽  
X Ray Diffraction ◽  
Excellent Thermal Stability ◽  
Heat Resistant ◽  
Graphite Structure ◽  
Thermal Stability Of

This work reports a boron- and silicon-containing phenolic-formaldehyde (PF) resin exhibiting an extremely high thermal decomposition temperature and char yield and formed by copolymerizing phenol, formaldehyde, boric acid (BA), and phenyltriethoxysilane (PTES). The structure of BA and PTES-modified PF (BSPF) resin was characterized by Fourier transform infrared spectroscopy. Thermal stability of the investigated composites was estimated by means of thermogravimetric analysis (TGA). The results of TGA indicated that the modified resin exhibited excellent thermal stability. Specifically, the thermoset had a char yield of 77.0% when the boron and silicon contents were only 1.27 wt% and 1.7 wt%, respectively. Compared with the unmodified resin (PF), the temperature at the maximum decomposing rate of the BSPF increased by 84°C and its charring yield was enhanced by 15.0%. The cured products of PF and BSPF were further investigated by X-ray diffraction and Raman spectroscopy, respectively. The incorporation of boron and silicon into the carbon lattice results in a decrease of interlayer spacing, and Raman ID/ IG values for PF and BSPF (2.63 and 1.32) show that the rearrangement of crystalline structure leads to an increase in graphite structure and a decrease in disordered structure upon the modification processes.

Microstructure studies of tungsten silicide schottky contacts on Gaas

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.

Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Beam ◽  
Hexagonal Structure ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Ion Beam Synthesis ◽  
Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

Study of Thermal Behaviour of EPDM/SBR Blends and Carbon Nanocoatings Deposited by Sputtering

2021 ◽  
Vol 875 ◽  
pp. 116-120
Author(s):  
Muhammad Alamgir ◽  
Faizan Ali Ghauri ◽  
Waheed Qamar Khan ◽  
Sajawal Rasheed ◽  
Muhammad Sarfraz Nawaz ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Thermal Behavior ◽  
Thermal Behaviour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.

Syntheses, Crystal Structures and Thermal Stability of Co(II) and Zn(II) Complexes with Ethyl Carbazate

2005 ◽  
Vol 60 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Tong-Lai Zhang ◽  
Jiang-Chuang Song ◽  
Jian-Guo Zhang ◽  
Gui-Xia Ma ◽  
Kai-Bei Yu
Keyword(s):  
Thermal Stability ◽  
Aqueous Solutions ◽  
Diffraction Analysis ◽  
Single Crystals ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Thermal Stabilities ◽  
X Ray ◽  
Thermal Stability Of

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.

STRUCTURE AND THERMAL STABILITY OF THE SULFIDE OVERLAYERS ON CH3CSNH2-PASSIVATED GaAs(100) SURFACES

2001 ◽  
Vol 08 (01n02) ◽  
pp. 19-23 ◽  
Author(s):  
F. Q. XU ◽  
E. D. LU ◽  
H. B. PAN ◽  
C. K. XIE ◽  
P. S. XU ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electron Spectroscopy ◽  
Photoemission Spectroscopy ◽  
Low Energy Electron Diffraction ◽  
Native Oxides ◽  
Sulfur Passivation ◽  
Different Temperatures ◽  
Low Energy Electron ◽  
Synchrotron Radiation Photoemission ◽  
Thermal Stability Of

Chemically sulfur passivation of GaAs(100) by thioacetamide ( CH 3 CSNH 2) has been studied using synchrotron radiation photoemission spectroscopy (SRPES), Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). The measurement of SRPES and AES showed that the top layer of native oxides over GaAs(100) was removed and the sulfides of Ga and As were formed after the passivation process. The thermal stability and surface structure have also been studied by annealing the passivated samples at different temperatures. We found that the surface sulfides could be removed gradually; as a result, a clean, ordered and thus Fermi level unpinning surface was finally achieved. The surface restructures with GaAs(100)–S(2×1) and 4×1 LEED patterns were observed on annealing above 260°C and at 550°C respectively.

scholarly journals Improved thermal stability of SiCf/SiC ceramic matrix composites fabricated by PIP process

2021 ◽  
Vol 15 (2) ◽  
pp. 164-169
Author(s):  
Jian Gu ◽  
Sea-Hoon Lee ◽  
Daejong Kim ◽  
Hee-Soo Lee ◽  
Jun-Seop Kim
Keyword(s):  
Thermal Stability ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Sic Fiber ◽  
Sic Ceramic ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Thermal Deterioration ◽  
Thermal Stability Of

Improvement of the thermal stability of continuous SiC fiber reinforced SiC ceramic matrix composites (SiCf/SiC CMC) by the pre-treatment of SiC fillers and the suppression of oxidation during polymer impregnation and pyrolysis (PIP) process were investigated. Dense SiCf/SiC CMCs were fabricated using the slurry infiltration and PIP process under a purified argon atmosphere. Structure and mechanical properties of the SiCf/SiC CMC heated at different temperatures were evaluated. The flexural strength of the SiCf/SiC CMC decreased only 15.3%after heating at 1400 ?C, which exhibited a clear improvement compared with the literature data (49.5% loss), where severe thermal deterioration of SiCf/SiC composite occurred at high temperatures by the crystallization and decomposition of the precursor-derived ceramic matrix. The thermal stability of the SiCf/SiC CMC fabricated by PIP process was improved by the pre-treatment of SiC fillers for removing oxides and the strict atmosphere control to prevent oxidation.

Thermal Stability of Solid Aluminum Electrolytic Capacitors with Conductive Polyaniline Counter Electrode

2012 ◽  
Vol 512-515 ◽  
pp. 1018-1021
Author(s):  
Xu Fei Zhu ◽  
Long Fei Jiang ◽  
Wei Xing Qi ◽  
Chao Lu ◽  
Ye Song
Keyword(s):  
Thermal Stability ◽  
Counter Electrode ◽  
Electrolytic Capacitor ◽  
Aluminum Electrolytic Capacitor ◽  
Dodecylbenzenesulfonic Acid ◽  
Excellent Thermal Stability ◽  
High Frequencies ◽  
Solid Aluminum ◽  
Good Thermal Stability ◽  
Thermal Stability Of

To overcome the risk of electrolyte leakage and the shortcoming of higher impedance at high frequencies for the conventional aluminum electrolytic capacitor impregnated with electrolyte solutions, solid aluminum electrolytic capacitor employing conducting polyaniline (PANI) as a counter electrode was developed. The as-fabricated solid capacitors have very low impedances at high frequencies and excellent thermal stability. The superior performances can be ascribed to high conductivity and good thermal stability of the camphorsulfonic acid (CSA)-dodecylbenzenesulfonic acid (DBSA) co-doped PANI.

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