scholarly journals Manufacturing Pitch and Polyethylene Blends-Based Fibres as Potential Carbon Fibre Precursors

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1445
Author(s):  
Salem Mohammed Aldosari ◽  
Muhammad A. Khan ◽  
Sameer Rahatekar
Keyword(s):  
Thermal Stability ◽  
Carbon Fibre ◽  
Phase Region ◽  
Carbon Fibres ◽  
Two Phase ◽  
Excellent Thermal Stability ◽  
Manufacturing Method ◽  
Polyethylene Blends ◽  
Potential Carbon ◽  
Potential Precursor

The advantage of mesophase pitch-based carbon fibres is their high modulus, but pitch-based carbon fibres and precursors are very brittle. This paper reports the development of a unique manufacturing method using a blend of pitch and linear low-density polyethylene (LLDPE) from which it is possible to obtain precursors that are less brittle than neat pitch fibres. This study reports on the structure and properties of pitch and LLDPE blend precursors with LLDPE content ranging from 5 wt% to 20 wt%. Fibre microstructure was determined using scanning electron microscopy (SEM), which showed a two-phase region having distinct pitch fibre and LLDPE regions. Tensile testing of neat pitch fibres showed low strain to failure (brittle), but as the percentage of LLDPE was increased, the strain to failure and tensile strength both increased by a factor of more than 7. DSC characterisation of the melting/crystallization behaviour of LLDPE showed melting occurred around 120 °C to 124 °C, with crystallization between 99 °C and 103 °C. TGA measurements showed that for 5 wt%, 10 wt% LLDPE thermal stability was excellent to 800 °C. Blend pitch/LLDPE carbon fibres showed reduced brittleness combined with excellent thermal stability, and thus are a candidate as a potential precursor for pitch-based carbon fibre manufacturing.

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.

Solution Properties and Phase Behavior of Ammonium Hexylene Octyl Succinate in Water and Water-Oil System

1970 ◽  
Vol 3 (1) ◽  
Author(s):  
Md. Hamidul Kabir ◽  
Ravshan Makhkamov ◽  
Shaila Kabir
Keyword(s):  
Critical Micelle Concentration ◽  
Phase Behavior ◽  
Liquid Crystalline ◽  
Carbon Number ◽  
Phase Region ◽  
Solution Properties ◽  
Middle Phase ◽  
Two Phase ◽  
Lamellar Liquid Crystal ◽  
Drug Ingredient

The solution properties and phase behavior of ammonium hexylene octyl succinate (HOS) was investigated in water and water-oil system. The critical micelle concentration (CMC) of HOS is lower than that of anionic surfactants having same carbon number in the lipophilic part. The phase diagrams of a water/ HOS system and water/ HOS/ C10EO8/ dodecane system were also constructed. Above critical micelle concentration, the surfactant forms a normal micellar solution (Wm) at a low surfactant concentration whereas a lamellar liquid crystalline phase (La) dominates over a wide region through the formation of a two-phase region (La+W) in the binary system. The lamellar phase is arranged in the form of a biocompatible vesicle which is very significant for the drug delivery system. The surfactant tends to be hydrophilic when it is mixed with C10EO8 and a middle-phase microemulsion (D) is appeared in the water-surfactant-dodecane system where both the water and oil soluble drug ingredient can be incorporated in the form of a dispersion. Hence, mixing can tune the hydrophile-lipophile properties of the surfactant. Key words: Ammonium hexylene octyl succinate, mixed surfactant, lamellar liquid crystal, middle-phase microemulsion. Dhaka Univ. J. Pharm. Sci. Vol.3(1-2) 2004 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

scholarly journals Boosted piezoelectricity with excellent thermal stability in tetragonal NaNbO3-based ceramics

2020 ◽  
Author(s):  
Lu Wang ◽  
Shengdong Sun ◽  
Huajie Luo ◽  
Yang Ren ◽  
Hui Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Temperature Stability ◽  
Lead Free ◽  
Excellent Thermal Stability ◽  
Lead Free Ceramics ◽  
Piezoelectric Performance

The realization of high piezoelectric performance and excellent temperature stability simultaneously in lead-free ceramics is the key for replacing Pb-containing perovskites in industry. In this study, large piezoelectric performance (d33...

scholarly journals Revisiting the Bøggild Intergrowth in Iridescent Labradorite Feldspars: Ordering, Kinetics, and Phase Equilibria

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 727
Author(s):  
Shiyun Jin ◽  
Huifang Xu ◽  
Seungyeol Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atom Probe ◽  
Phase Region ◽  
Two Phase ◽  
Subsolidus Phase ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

The enigmatic Bøggild intergrowth in iridescent labradorite crystals was revisited in light of recent work on the incommensurately modulated structures in the intermediated plagioclase. Five igneous samples and one metamorphic labradorite sample with various compositions and lamellar thicknesses were studied in this paper. The lamellar textures were characterized with conventional transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The compositions of individual lamellae were analyzed with high-resolution energy-dispersive X-ray spectroscopy (EDS) mapping and atom probe tomography (APT). The average structure states of the studied samples were also compared with single-crystal X-ray diffraction data (SC-XRD). The Na-rich lamellae have a composition of An44–48, and the Ca-rich lamellae range from An56 to An63. Significant differences between the lamellar compositions of different samples were observed. The compositions of the Bøggild intergrowth do not only depend on the bulk compositions, but also on the thermal history of the host rock. The implications on the subsolidus phase relationships of the plagioclase feldspar solid solution are discussed. The results cannot be explained by a regular symmetrical solvus such as the Bøggild gap, but they support an inclined two-phase region that closes at low temperature.

scholarly journals The influence of an ultra-high resistivity Ta underlayer on perpendicular magnetic anisotropy in Ta/Pt/Co/Pt heterostructures

RSC Advances ◽  
2020 ◽  
Vol 10 (19) ◽  
pp. 11219-11224
Author(s):  
Wei Zhang ◽  
Xiaoxiong Jia ◽  
Rui Wang ◽  
Huihui Liu ◽  
Zhengyu Xiao ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Magnetic Anisotropy ◽  
High Stability ◽  
Essential Role ◽  
Perpendicular Magnetic Anisotropy ◽  
Low Energy ◽  
High Resistivity ◽  
Excellent Thermal Stability ◽  
Low Energy Consumption

Thin films with perpendicular magnetic anisotropy (PMA) play an essential role in the development of technologies due to their excellent thermal stability and potential application in devices with high density, high stability, and low energy consumption.

Preparation of polyetheretherketone composites with nanohydroxyapatite rods and carbon nanofibers having high strength, good biocompatibility and excellent thermal stability

RSC Advances ◽  
2016 ◽  
Vol 6 (23) ◽  
pp. 19417-19429 ◽  
Author(s):  
Kai Wang Chan ◽  
Cheng Zhu Liao ◽  
Hoi Man Wong ◽  
Kelvin Wai Kwok Yeung ◽  
Sie Chin Tjong
Keyword(s):  
Thermal Stability ◽  
Carbon Nanofibers ◽  
Hybrid Composite ◽  
High Strength ◽  
Excellent Thermal Stability ◽  
Good Biocompatibility

The WST-1 assay shows that the PEEK/15 vol% nHA–1.9 vol% CNF hybrid composite has excellent biocompatibility.

Tensometry of carbon fibres and elastomers at the diffractometer at BL20B of the Photon Factory

1998 ◽  
Vol 5 (3) ◽  
pp. 958-961
Author(s):  
D. C. Creagh ◽  
P. M. O'Neill ◽  
R. J. Mills ◽  
S. A. Holt
Keyword(s):  
Carbon Fibre ◽  
Duty Cycle ◽  
Simultaneous Recording ◽  
The Other ◽  
Imaging Plate ◽  
Relaxation Processes ◽  
Carbon Fibres ◽  
Fixed Rate ◽  
Photon Factory ◽  
System Use

Two systems have been developed for the simultaneous recording of the SAXS and the WAXS patterns from carbon fibre and elastomer samples which are placed under stress. The systems have been designed to fit inside the versatile vacuum diffractometer (BIGDIFF) at the Photon Factory. In one system, use is made of the ability to move the imaging-plate cassette. In the other, use has been made of an imaging-plate changer which can deliver up to 13 plates into position with a duty cycle of about 60 s. In this case each imaging plate can record SAXS/WAXS patterns in the range 0.5–20° due to the passage of the beam through the specimen which is mounted in a specially designed tensometer. Because BIGDIFF is a vacuum diffractometer and parasitic scattering is small, exposure times as short as 2 s can give acceptable SAXS/WAXS patterns. The systems have been used for the study of both the change of structure with strain, and the relaxation processes which occur as a result of the sample being strained at a fixed rate by a predetermined amount.

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