scholarly journals Еffect of graphene filler oxidation on the thermal destruction of epoxy-graphene composites

Surface ◽  
2021 ◽  
Vol 13(28) ◽  
pp. 166-174
Author(s):  
N. V. Sigareva ◽  
◽  
B. M. Gorelov ◽  
S. V. Shulga ◽  
◽  
...  
Keyword(s):  
Heat Resistance ◽  
Epoxy Resin ◽  
Thermal Destruction ◽  
Filler Content ◽  
Atomic Layer ◽  
Electronic Subsystem ◽  
X Ray Diffraction ◽  
Electron Subsystem ◽  
Graphene Electron ◽  
Graphene Nanoparticles

The participation of the electronic subsystem of graphene nanoparticles in heat transfer on the interfaphase surface with epoxy polymer, its participation in the thermodestruction processes of epoxy matrix and the concentration interval of the subsystem's influence on the thermal destruction of the polymer matrix are investigated. For such purpose, epoxy resin composites with oxidized and non-oxidized graphene nanoparticles have been used.The particles were obtained by electrochemical method and those are characterized by the same dispersion and analogical of defect spectra. The particles have the same crystal structure, however in composites with oxidized graphene, the participation of the electronic subsystem in thermophysical processes on the interfacial surface is blocked by the atomic layer of adsorbed oxygen. Сomposites of epoxy resin filled with the same particles of nonoxidized and oxidized nanoparticles in the filler content 0.0, 1.0, 2.0, and 5.0 wt%. The multilayered graphene particles were studied by X-ray diffraction analysis (XRD) and Raman spectroscopy (RS) methods. It was shown that the graphene particles are the 2D dimensional structures with about of 100 layers. Desorption curves of epoxy and its composites have been obtained using a programmable thermal desorption mass-spectroscopic (TDMS) technique for fragments with 15≤ m/z ≤108 and temperature interval 35 - 800 оС. The activation energy of desorption was determined from the Wigner-Polanyi equation as 35 - 150 kJ/mol, temperature and mass dependences of the quantity of desorbed atomic fragments have been calculated. It were established the graphene electron subsystem takes part in polymer structure thermodestruction for epoxy composites with nonoxidized graphene enhancing their heat resistance at graphene content С ≤ 1 wt%. With increasing filler content, the thermodestruction behavior in pristine epoxy and its composites with nonoxidized and oxidized graphene is analogical. The thermodestruction characterizes by the stepwise variations in the desorption intensity of atomic fragments. The electron subsystem of graphene particles does not participate in the heat resistance variations.

Depositing High-Performance Conductive Thin Films by Using Atomic Layer Deposition

2015 ◽  
Vol 764-765 ◽  
pp. 138-142 ◽  
Author(s):  
Fa Ta Tsai ◽  
Hsi Ting Hou ◽  
Ching Kong Chao ◽  
Rwei Ching Chang
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
High Performance ◽  
Atomic Layer ◽  
Electric Properties ◽  
X Ray Diffraction ◽  
Layer Deposition ◽  
Azo Thin Film ◽  
Aluminum Doped Zinc Oxide ◽  
Conductive Thin Films

This work characterizes the mechanical and opto-electric properties of Aluminum-doped zinc oxide (AZO) thin films deposited by atomic layer deposition (ALD), where various depositing temperature, 100, 125, 150, 175, and 200 °C are considered. The transmittance, microstructure, electric resistivity, adhesion, hardness, and Young’s modulus of the deposited thin films are tested by using spectrophotometer, X-ray diffraction, Hall effect analyzer, micro scratch, and nanoindentation, respectively. The results show that the AZO thin film deposited at 200 °C behaves the best electric properties, where its resistance, Carrier Concentration and mobility reach 4.3×10-4 Ωcm, 2.4×1020 cm-3, and 60.4 cm2V-1s-1, respectively. Furthermore, microstructure of the AZO films deposited by ALD is much better than those deposited by sputtering.

Investigation of the Effect of the Length and Content of Carbon Fibers on the Properties of Polyphenylene Sulfide

2020 ◽  
Vol 869 ◽  
pp. 474-480
Author(s):  
Azamat L. Slonov ◽  
Ismel V. Musov ◽  
Elena V. Rzhevskaya ◽  
Azamat Zhansitov ◽  
Svetlana Yu. Khashirova
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Heat Resistance ◽  
Carbon Fibers ◽  
Filler Content ◽  
Sharp Decrease ◽  
Polyphenylene Sulfide ◽  
Average Particle ◽  
Melt Flow Rate ◽  
Particle Length

The article presents the results of a study of the effect of milled and chopped carbon fibers, with an average particle length of 0.2 and , respectively, on the mechanical properties of polyphenylene sulfide and its heat resistance. It was found that the introduction of carbon fibers leads to a significant decrease in the melt flow rate. It was shown that after a sharp decrease in impact strength at 10 % content of carbon fibers, its inverse improvement occurs with an increase in the filler content. Composites containing carbon fibers with length demonstrate higher impact strength. The introduction of a filler leads to a significant increase in the elastic modulus and strength of polyphenylene sulfide and its heat resistance.

Ex-situ X-ray diffraction analysis of electrode strain at TiO2 atomic layer deposition/α-MoO3 interface in a novel aqueous potassium ion battery

2016 ◽  
Vol 316 ◽  
pp. 160-169 ◽  
Author(s):  
Nicholas David Schuppert ◽  
Santanu Mukherjee ◽  
Alex M. Bates ◽  
Eun-Jin Son ◽  
Moon Jong Choi ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Diffraction Analysis ◽  
Atomic Layer ◽  
Potassium Ion ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layer Deposition

An algorithm for calculating diffraction profiles of 2θ scans for multiple diffraction from crystals and thin films

2014 ◽  
Vol 70 (6) ◽  
pp. 572-582
Author(s):  
Hsin-Yi Chen ◽  
Mau-Sen Chiu ◽  
Chia-Hung Chu ◽  
Shih-Lin Chang
Keyword(s):  
Initial Phase ◽  
Atomic Layer ◽  
Dynamical Theory ◽  
Far Field ◽  
X Rays ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
X Ray ◽  
Beam Surface ◽  
Surface Diffraction

An algorithm is developed based on the dynamical theory of X-ray diffraction for calculating the profiles of the diffracted beam,i.e.the diagrams of the intensity distributionversus2θ when a crystal is fixed at an angle of its maximum diffracted intensity. Similar to Fraunhofer (far-field) diffraction for a single-slit case, in the proposed algorithm the diffracted beam from one atomic layer excited by X-rays is described by the composition of (N+ 1) coherent point oscillators in the crystal. The amplitude and the initial phase of the electric field for each oscillator can be calculated based on the dynamical theory with given boundary conditions. This algorithm not only gives diffraction profiles but also provides the contribution of the excitation of modes when extremely asymmetric diffraction is involved in the diffraction process. Examples such as extremely asymmetric two-beam surface diffraction and three-beam surface diffraction are presented and discussed in detail.

scholarly journals Direct Epitaxial Nanometer-Thin InN of High Structural Quality on 4H-SiC by Atomic Layer Deposition

2020 ◽  
Author(s):  
Chih-Wei Hsu ◽  
Petro Deminskyi ◽  
Ivan Martinovic ◽  
Ivan G. Ivanov ◽  
Justinas Palisaitis ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Indium Nitride ◽  
Atomic Layer ◽  
Structural Quality ◽  
High Electron ◽  
X Ray Diffraction ◽  
High Quality ◽  
Subsequent Formation ◽  
Transmission Electron ◽  
Layer Deposition

<div>Indium nitride (InN) is a highly promising material for high frequency electronics given its</div><div>low band gap and high electron mobility. The development of InN-based devices is hampered</div><div>by the limitations in depositing very thin InN films of high quality. We demonstrate growth of</div><div>high-structural-quality nanometer thin InN films on 4H-SiC by atomic layer deposition (ALD).</div><div>High resolution X-ray diffraction and transmission electron microscopy show epitaxial growth</div><div>and an atomically sharp interface between InN and 4H-SiC. The InN film is fully relaxed already after a few atomic layers and shows a very smooth morphology where the low surface</div><div>roughness (0.14 nm) is found to reproduced sub-nanometer surface features of the substrate. Raman measurements show an asymmetric broadening caused by grains in the InN film. Our results show the potential of ALD to prepare high quality nanometer-thin InN films for subsequent formation of heterojunctions.</div>

scholarly journals The effect of additives metal on the D.C conductivity of epoxy resin

2011 ◽  
Vol 8 (1) ◽  
pp. 168-174
Author(s):  
Baghdad Science Journal
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Epoxy Resin ◽  
Filler Content ◽  
Experimental Results ◽  
Filler Concentration ◽  
Effect Of Additives

The present studies are focused on the modification of the properties of epoxy resin with different additives namely aluminum, copper by preparing of composites systems with percentage (20%, 40% and 50%) of the above additives. The experimental results show that the D.C of conductivity on wt% filler content at ( 293-413 ) K electrical conductivity of all above composites increased with temperature for composites with filler contact and find the excellent electrical conductivity of copper and lie between (2.6*10-10 - 2.1*10-10)?.cm . The activation energy of the electrical conductivity is determined and found to decrease with increasing the filler concentration.

scholarly journals Influence of filler content on trap and space charge properties of epoxy resin nanocomposites

2017 ◽  
Vol 66 (9) ◽  
pp. 097701
Author(s):  
Yuan Duan-Lei ◽  
Min Dao-Min ◽  
Huang Yin ◽  
Xie Dong-Ri ◽  
Wang Hai-Yan ◽  
...  
Keyword(s):  
Space Charge ◽  
Epoxy Resin ◽  
Filler Content ◽  
Epoxy Resin Nanocomposites

Wear Behavior of TiB2/GNPs and B4C/GNPs Reinforced AA6061 Matrix Composites

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Safa Polat ◽  
Yavuz Sun ◽  
Engin C¸evik
Keyword(s):  
Wear Behavior ◽  
Sem Analysis ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Pressure Infiltration ◽  
X Ray ◽  
Wear Rates ◽  
Graphene Nanoparticles ◽  
Infiltration Method ◽  
Scanning Electron

Abstract In this study, it was aimed to investigate the effects of reinforcements used for improving the thermal properties of AA6061 alloy on wear resistance. For this purpose, AA6061 matrix composites were produced by pressure infiltration method using ceramic microparticles (TiB2 and B4C) and graphene nanoparticles (GNPs). The produced composites were first characterized by porosity measurement, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. Then, the wear behavior was examined under three different loads (20–40–60 N) with the reciprocating ball on the flat method in a dry environment. Specific wear-rates were calculated according to the Archard principle by measuring the depth and width of the traces after tests with a profilometer. Wearing mechanisms were determined with the help of optical and microstructure images. According to the obtained results, it was found that B4C + GNPs reinforced samples were more resistant to abrasion at low loads, but TiB2 + GNPs reinforced samples were higher at higher loads.

Curing Process and Heat-Resistance of Polyethersulfone Toughened Epoxy Resins

2017 ◽  
Vol 898 ◽  
pp. 2302-2308
Author(s):  
Jin Li Zhou ◽  
Shu Zhu ◽  
Wen Pin Jia ◽  
Chao Cheng ◽  
Elwathig A.M. Hassan ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Epoxy Resin ◽  
Thermo Gravimetric Analysis ◽  
Exothermic Peak ◽  
Curing Temperature ◽  
Gravimetric Analysis ◽  
Curing Process ◽  
Thermo Gravimetric ◽  
Rich Phase ◽  
Curing Reaction

In order to improve the toughness of epoxy resin, hydroxyl-terminated polyethersulfone (PES) with various amounts (0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%) were added to bisphenol A epoxy resin (DER331)/ curing agent DETDA (E100) systems, and the influence of PES contents on curing process and heat-resistance was studied. Non-isothermal DSC was used to determine the curing process of uncured DER331/E100/PES systems at heating rate of 2°C/min, 5°C/min, 7°C/min, 10°C/min and 15°C/min separately, and the apparent activation energy was calculated based on Kissinger method. The morphology of the etched cured DER331/E100/PES systems with different PES contents was observed by SEM. The heat-resistance of these systems was investigated by DSC and TGA. The results showed that with the increasing of PES content the curing exothermic peak, the heat of curing reaction, the initial and final curing temperature all decreased at the first and then increased, indicating that when the PES content was low (5 wt.%, 10 wt.%), PES can facilitate the curing process, while, when PES content up to 15 wt.%, PES can prevent or weaken the curing reaction. SEM results indicated that the phase structure changed drastically depending on the PES content. The systems with 5 wt.% and 10 wt.% PES were epoxy-rich phase, with 15 wt.% PES was co-continuity phase, and with 20 wt.% PES showed complete phase inversion (PES rich phase). The glass transition temperature and thermo gravimetric analysis demonstrated that the addition of PES can increase the heat resistance of cured DER331/E100/PES systems.

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