Electrical Properties of Sbcl5, Icl, Hno3, and Br2 Intercalated Pitch Based Carbon Fibers

1982 ◽  
Vol 20 ◽  
Author(s):  
V. Natarajan ◽  
John A. Woollam
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Electrical Properties ◽  
Carbon Fibers ◽  
Room Temperature ◽  
Double Sequence ◽  
Electrical Resistivities

ABSTRACTHighly graphitized pitch based carbon fibers with heat treatment temperatures (HTT) of 2500°C, and 3000°C have been intercalated with SbCl5, ICl, HNO3, and Br2. These were reacted either by themselves alone, or in double sequence (e.g. Br2 followed by SbCl5). The electrical resistivities of individual fibers were then measured in air, and as a function of temperature, to a series of temperatures, to test air and thermal stability. The lowest resistivity found in this sequence so far is 28 micro ohm cm when ICl intercalation was followed by HNO3 reaction. These conductors are sometimes air stable (depending on intercalant) at room temperature and can be heated somewhat, but begin to deintercalate at much lower temperatures than was found for CuCl2 intercalated fibers [1,2]. In comparison with the CuCl2 reaction with pitch fibers, these intercalants react easily, and thesequential intercalations appear to give lower final resistivities.

scholarly journals Стабильность функциональных характеристик прозрачных электродов на основе трехслойной структуры ZnO : Ga/Ag/ZnO : Ga

2022 ◽  
Vol 48 (2) ◽  
pp. 51
Author(s):  
А.Ш. Асваров ◽  
А.К. Ахмедов ◽  
А.Э. Муслимов ◽  
В.М. Каневский
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Room Temperature ◽  
Layer Structure ◽  
Visible Range ◽  
Practical Application ◽  
Transparent Conducting ◽  
Average Transmittance ◽  
The Stability

Since to the stability of the functional properties of a transparent conducting three-layer structure ZnO:Ga/Ag/ZnO:Ga is important for practical application, we studied its long-term durability and thermal stability in air environment. It has been demonstrated that after prolonged interaction with the air environment at room temperature (~ 1000 h) and further heat treatment in air at temperatures up to 450 ° C (up to 10 h), the three-layer structure retains its integrity and is characterized by a low sheet resistance Rs = 2.8 Ω/sq at average transmittance in the visible range Tav of 82.1%.

Electrical properties of plastic composites using Br2-intercalated vapor-grown carbon fibers as a conductive filler

1994 ◽  
Vol 9 (7) ◽  
pp. 1829-1833 ◽  
Author(s):  
M. Katsumata ◽  
M. Endo ◽  
H. Yamanashi ◽  
H. Ushijima
Keyword(s):  
Electrical Properties ◽  
Carbon Fibers ◽  
Room Temperature ◽  
Conductive Filler ◽  
Plastic Composite ◽  
Plastic Composites ◽  
Liquid Bromine ◽  
Degree Of Stability ◽  
High Degree ◽  
Powder Resistivity

Graphite fiber intercalation compounds were prepared by immersing graphitized thin vapor-grown carbon fibers (VGCF's) with diameters less than 0.5 μm into liquid bromine. The composition of Br2-intercalated VGCF was C70Br-C90Br. The powder resistivity of Br2-intercalated VGCF was estimated as 1/3 of pristine VGCF. An electroconductive plastic composite was prepared by mixing phenol resin with that of bromine intercalated VGCF as a conductive filler, and its electrical properties were investigated. The resistivity of a Br2-intercalated VGCF composite was 1.1 × 10−2 Ω · cm at room temperature, which is about 50% of pristine VGCF composite. Br2-intercalated VGCF-based composite had a high degree of stability against exposure at 150 °C in air and at 85 °C with 90% humidity for 500 h. Br2-intercalated VGCF-based plastic composites could be used as highly electroconductive materials.

The preparation and electrical properties of TiO2−xFx

1988 ◽  
Vol 3 (2) ◽  
pp. 392-397 ◽  
Author(s):  
Tadashi Endo ◽  
Naoki Morita ◽  
Tsugio Sato ◽  
Masahiko Shimada
Keyword(s):  
Solid Solution ◽  
Electrical Properties ◽  
Diffraction Data ◽  
Room Temperature ◽  
Single Phase ◽  
Fluorine Content ◽  
Band Model ◽  
Electric Conduction ◽  
Electrical Resistivities ◽  
The Relationship

The substitution of fluorine for oxygen in TiO2 was investigated by the reaction of Ti2O3, TiO2, and TiF3 under conditions of 4–6.5 GPa and 700–1400°C. The single phase of TiO2−x Fx solid solution was obtained in the region of 0≤x≤0.7. According to the x-ray diffraction data, the a and c axes of the rutile-type structure linearly increased with increasing fluorine content. The electrical resistivities of TiO2−x Fx were in the range from 10 Ω cm for x = 0.3 to 850 Ω cm for x = 0.7 at 300 K and the relationship between In ρ and 1000/T was linear. The activation energies were estimated to be from 0.17 eV at x = 0.3 to 0.28 eV at x = 0.7. Also, the thermoelectric powers at room temperature changed from 250μV/K to + 50 μV/K. The mechanism of electric conduction was discussed on the basis of the extended band model of rutile.

Controlled Growth of WO3-Loaded TiO2 Nanotubes for Tandem Solar-Driven Water Splitting Cell

2015 ◽  
Vol 1109 ◽  
pp. 243-247
Author(s):  
Chin Wei Lai ◽  
Kung Shiuh Lau ◽  
Sharifah Bee Abd Hamid
Keyword(s):  
Thermal Stability ◽  
Electrical Properties ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Room Temperature ◽  
Solar Spectrum ◽  
Comparison Results ◽  
Excellent Chemical ◽  
Study Development ◽  
Pec Water Splitting

Nowadays, hydrogen production using solar-driven photoelectrochemical (PEC) water splitting has attracted considerable attention since the introduction of TiO2 photoelectrodes. However, TiO2 is not able to split water on its own because the cleavage requires more than 1.4 V or even up to 1.9 V, including the redox potential of water (1.23 V) and unavoidable over-potentials. Many semiconductors have been studied, but only a very few large band gap materials can generate enough photo-voltage to cleave water for a single photoelectrode PEC water splitting cell especially processing under solar illumination. In the present study, development of WO3-loaded TiO2 nanotubes (WTNT) is a possible solution to generate a voltage that is high enough to split the water while absorbing more light (photons) from a greater part of solar spectrum. Furthermore, WTNT offered several advantages over the pure TiO2 photoelectrode, such as excellent chemical and thermal stability, active at room temperature as well as responsive to UV and visible illumination. The paper concludes by presenting the comparison results between unmodified TiO2 and WTNT photoelectrode in term of morphology, phase, elemental analysis, electrical properties, and electrochemical properties for the tandem solar-driven water splitting cell.

scholarly journals Remarkable Temperature Sensitivity of Partially Carbonized Carbon Fibers with Different Microstructures and Compositions

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7085
Author(s):  
Zijin Liu ◽  
Jun Wang ◽  
Chang Li ◽  
Cheng Zheng ◽  
Bin Zhang
Keyword(s):  
Heat Treatment ◽  
Carbon Fibers ◽  
Temperature Sensitivity ◽  
Negative Temperature ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
X Ray ◽  
Graphitization Degree ◽  
Electrical Resistivities ◽  
Transfer Method

In order to explore effect of structure on the temperature sensitivity of partially carbonized carbon fibers, different heat treatment temperatures (700, 750 and 800 °C) and heat treatment times (3 and 9 min) were used to prepare fibers with different structures. The electrical resistivities were monitored whilst the room temperature was increased from 30 to 100 °C, which was used to characterize the temperature sensitivity. The fibers showed negative temperature coefficients in the temperature range. Infrared spectra, an element analysis, a scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction measurements were used to study the microstructure of the fibers. Through the analysis, the proportions of the graphite-like structure, graphitization degree and size of the graphite-like structure crystallite influenced the temperature sensitivity. The main electron transfer method used for the fibers was variable-range hopping. This indicated that the fibers had a potential application of preparing thermistors in polymer composites.

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