scholarly journals Mechanochemically Carboxylated Multilayer Graphene for Carbon/ABS Composites with Improved Thermal Conductivity

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1088 ◽  
Author(s):  
Laura Burk ◽  
Matthias Gliem ◽  
Fabian Lais ◽  
Fabian Nutz ◽  
Markus Retsch ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Single Step ◽  
Melt Processing ◽  
Multilayer Graphene ◽  
Carbon Filler ◽  
Layer Graphene ◽  
Few Layer Graphene

Dry ball milling of graphite under carbon dioxide pressure affords multilayer-functionalized graphene (MFG) with carboxylic groups as nanofiller for composites of carbon and acrylonitrile–butadiene–styrene copolymers (ABSs). Produced in a single-step process without requiring purification, MFG nanoplatelets are uniformly dispersed in ABS even in the absence of compatibilizers. As compared to few-layer graphene oxide, much larger amounts of MFG are tolerated in ABS melt processing. Unparalleled by other carbon nanofillers and non-functionalized micronized graphite, the addition of 15 wt % MFG simultaneously results in a Young’s modulus of 2550 MPa (+68%), a thermal conductivity of 0.321 W∙m−1∙K−1 (+200%), and a heat distortion temperature of 99 °C (+9%) with respect to neat ABS, without encountering massive embrittlement and melt-viscosity build-up typical of few-layer graphene oxide. With carbon filler at 5 wt %, the Young’s modulus increases with increasing aspect ratio of the carbon filler and is superior to spherical hydroxyl-functionalized MFG, which forms large agglomerates. Both MFG and micronized graphite hold promise for designing carbon/ABS compounds with improved thermal management in lightweight engineering applications.

scholarly journals Experimental Characterization and Modeling Multifunctional Properties of Epoxy/Graphene Oxide Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2831
Author(s):  
Naresh Kakur ◽  
Kamran A. Khan ◽  
Rehan Umer
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Image Correlation ◽  
Poisson's Ratio ◽  
Mechanical And Thermal Properties ◽  
Temperature Dependent ◽  
Frequency Temperature

Thermomechanical modeling of epoxy/graphene oxide under quasi-static and dynamic loading requires thermo-mechanical properties such as Young’s modulus, Poisson’s ratio, thermal conductivity, and frequency-temperature dependent viscoelastic properties. In this study, the effects of different graphene oxide (GO) concentrations (0.05, 0.1, and 0.2 wt%) within an epoxy matrix on several mechanical and thermal properties were investigated. The distribution of GO fillers in the epoxy was investigated using transmission electron microscopy (TEM). The digital image correlation (DIC) technique was employed during the tensile testing to determine Young’s modulus and Poisson’s ratio. Analytical models were used to predict Young’s modulus and thermal conductivity, with an error of less than 13% and 9%, respectively. Frequency–temperature dependent phenomenological models were proposed to predict the storage moduli and loss tangent, with a reasonable agreement with experimental data. A relatively high storage modulus, heat-resistance index (THRI), and thermal conductivity were observed in 0.2 wt% nanocomposite samples compared with pure epoxy and other lower concentration GO nanocomposites. A high THRI and derivative of thermogravimetric analysis peak temperatures (Tm1 and Tm2) were exhibited by adding nano-fillers in the epoxy, which confirms higher thermal stability of nanocomposites than that of pristine epoxy.

Mechanical and thermal properties of graphene–carbon nanotube-reinforced metal matrix composites: A molecular dynamics study

2016 ◽  
Vol 51 (23) ◽  
pp. 3299-3313 ◽  
Author(s):  
Sumit Sharma ◽  
Pramod Kumar ◽  
Rakesh Chandra
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Single Layer ◽  
Dynamics Simulation ◽  
Single Layer Graphene ◽  
Graphene Sheets ◽  
Layer Graphene

Single layer graphene sheets and carbon nanotubes have resulted in the development of new materials for a variety of applications. Though there are a large number of experimental and numerical studies related to these nanofillers, still there is a lack of understanding of the effect of geometrical characteristics of these nanofillers on their mechanical properties. In this study, molecular dynamics simulation has been used to assess this issue. Two different computational models, single layer graphene sheets–copper and carbon nanotube–copper composites have been examined to study the effect of nanofiller geometry on Young’s modulus and thermal conductivity of these nanocomposites. Effect of increase in temperature on Young’s modulus has also been predicted using molecular dynamics. The effect of nanofiller volume fraction ( Vf) on Young’s modulus and thermal conductivity has also been studied. Results of thermal conductivity obtained using molecular dynamics have been compared with theoretical models. Results show that with increase in Vf the Young’s modulus as well as thermal conductivity of single layer graphene sheets–Cu composites increases at a faster rate than that for carbon nanotube–Cu composite. For the same Vf, the Young’s modulus of single layer graphene sheets–Cu composite is higher than carbon nanotube–Cu composite.

Out-of-plane shear and out-of plane Young’s modulus of double-layer graphene

2013 ◽  
Vol 564 ◽  
pp. 37-40 ◽  
Author(s):  
Balázs Hajgató ◽  
Songül Güryel ◽  
Yves Dauphin ◽  
Jean-Marie Blairon ◽  
Hans E. Miltner ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Double Layer ◽  
Young's Modulus ◽  
Plane Shear ◽  
Layer Graphene ◽  
Out Of Plane

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

scholarly journals Regulation Mechanism of Graphene Oxide on the Structure and Mechanical Properties of Bio-Based Gel-Spun Lignin/Poly (Vinyl Alcohol) Fibers

2021 ◽  
Author(s):  
Yanhong Jin ◽  
Yuanyuan Jing ◽  
Wenxin Hu ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Young’S Modulus ◽  
Vinyl Alcohol ◽  
Young's Modulus ◽  
Lignin Content ◽  
Poly Vinyl Alcohol ◽  
Regulation Mechanism ◽  
Composite Fibers

Abstract Lignin has been used as a sustainable and eco-friendly filler in composite fibers. However, lignin aggregation occurred at high lignin content, which significantly hindered the further enhancement of fiber performance. The incorporation of graphene oxide (GO) enhanced the mechanical properties of the lignin/poly(vinyl alcohol) (PVA) fibers and affected their structure. With the GO content increasing from 0 to 0.2%, the tensile strength of 5% lignin/PVA fibers increased from 491 MPa to 631 MPa, and Young's modulus increased from 5.91 GPa to 6.61 GPa. GO reinforced 30% lignin/PVA fibers also showed the same trend. The tensile strength increased from 455 MPa to 553 MPa, and Young's modulus increased from 5.39 GPa to 7 GPa. The best mechanical performance was observed in PVA fibers containing 5% lignin and 0.2% GO, which had an average tensile strength of 631 MPa and a Young’s modulus of 6.61 GPa. The toughness values of these fibers are between 9.9-15.6 J/g, and the fibrillar and ductile fracture microstructure were observed. Structure analysis of fibers showed that GO reinforced 5% lignin/PVA fibers had higher crystallinity, and evidence of hydrogen bonding among GO, lignin, and PVA in the gel fibers was revealed. Further, water resistance and swelling behavior of composite PVA fibers were studied to further evidence the structure change of composite fibers.

Facile Synthesis of Few-Layer Graphene Oxide from Cinnamomum camphora

2021 ◽  
Vol 16 (2) ◽  
pp. 183-187
Author(s):  
Athiyanam Venkatesan Ramya ◽  
Neethu Joseph ◽  
Manoj Balachandran
Keyword(s):  
Graphene Oxide ◽  
Cinnamomum Camphora ◽  
Facile Synthesis ◽  
Layer Graphene ◽  
Few Layer Graphene

Graphene oxide and zinc oxide decorated chitosan nanocomposite biofilms for packaging applications

2020 ◽  
Vol 40 (2) ◽  
pp. 152-157 ◽  
Author(s):  
Pınar Terzioglu ◽  
Yasin Altin ◽  
Ayse Kalemtas ◽  
Ayse Celik Bedeloglu
Keyword(s):  
Tensile Strength ◽  
Zinc Oxide ◽  
Graphene Oxide ◽  
Composite Film ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Chitosan Film ◽  
Oxide Composite ◽  
Wide Range

AbstractRecently, due to sustainable development and environmental protection policies, there is increasing interest in the development of new biodegradable polymer-based multifunctional composites. Chitosan is one of the most remarkable and preferred biopolymers, which is environmentally friendly as well as renewable, biocompatible, and inexpensive. Though it has a wide range of potential applications, the major limitation of chitosan – the problem of poor mechanical performance – needs to be solved. In this work, graphene oxide was first produced and then used to manufacture a chitosan/graphene oxide/zinc oxide composite film through a casting method. The properties of the chitosan film and the chitosan/graphene oxide/zinc oxide composite film were investigated using Fourier transform infrared spectroscopy, mechanical, thermal gravimetric, and ultraviolet (UV)-visible spectroscopy analyses. The results showed that the incorporation of graphene oxide and zinc oxide into the chitosan matrix resulted in enhanced mechanical properties and thermal stability of chitosan biocomposite films. The graphene oxide- and zinc oxide-reinforced chitosan film showed 2527 MPa and 55.72 MPa of Young’s modulus and tensile strength, respectively, while neat chitosan showed only 1549 MPa and 37.91 MPa of Young’s modulus and tensile strength, respectively. Conversely, the addition of graphene oxide decreased the transmittance, notably in the UV region.

scholarly journals Neutron Multiple Number as a Factor Ruling Both the Abundance and Some Material Properties of Elements

2017 ◽  
Vol 6 (3) ◽  
pp. 37
Author(s):  
Yoshiharu Mae
Keyword(s):  
Thermal Conductivity ◽  
Young’S Modulus ◽  
Melting Temperature ◽  
Material Properties ◽  
Young's Modulus ◽  
Materials Properties ◽  
Unique Pattern ◽  
The Universe

The abundance of elements in the universe was plotted on the TC-YM diagram. The most abundant elements show the unique pattern drawing a quadrant. Next, the neutron multiple number, the number of neutron per proton in the nucleus, was introduced. The neutron multiple numbers of elements show the same pattern as the abundance of elements on the diagram. As a result, the abundance of elements shows a good correlation with neutron multiple numbers of elements. With increasing neutron multiple number, the abundance decreases. Besides, the neutron multiple number relates to the materials properties such as the Young’s modulus, thermal conductivity and melting temperature of elements.

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