Scope of Polymer/Graphene Nanocomposite in Defense Relevance

2019 ◽  
pp. 296-315
Author(s):  
Ayesha Kausar
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electromagnetic Interference ◽  
Optical Transmittance ◽  
Electrostatic Charge ◽  
Future Perspective ◽  
Flame Resistance ◽  
Nanocarbon Material ◽  
Ballistic Protection ◽  
Graphene Nanocomposite

This chapter outlines important aspects and progression from graphene to polymer/graphene nanocomposite to a relevant defense application. Graphene is unique nanocarbon material having a large surface area, high Young's modulus, thermal conductivity, electrical conductivity, and optical transmittance. Engineering thermoplastic polymers have been employed as matrices for graphene reinforcement. Various routes have been employed for graphene-filled polymeric nanomaterials. Intrinsic physical properties of nanocomposite depend on graphene modification and dispersion techniques. Polymer/graphene nanocomposite may have multifunctional characteristics due to synergistic effect of polymer/graphene. The article mainly discusses nanocomposite with potential uses in soldierly applications including flame resistance, ballistic protection, electromagnetic interference shielding, electrostatic-charge dissipation, sensors, corrosion protection, fuel cell, batteries, etc. The gestalt of defense applications of polymer/graphene nanocomposite may offer future perspective to develop promising materials.

Scope of Polymer/Graphene Nanocomposite in Defense Relevance

2021 ◽  
pp. 597-616
Author(s):  
Ayesha Kausar
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electromagnetic Interference ◽  
Optical Transmittance ◽  
Electrostatic Charge ◽  
Future Perspective ◽  
Flame Resistance ◽  
Nanocarbon Material ◽  
Ballistic Protection ◽  
Graphene Nanocomposite

This chapter outlines important aspects and progression from graphene to polymer/graphene nanocomposite to a relevant defense application. Graphene is unique nanocarbon material having a large surface area, high Young's modulus, thermal conductivity, electrical conductivity, and optical transmittance. Engineering thermoplastic polymers have been employed as matrices for graphene reinforcement. Various routes have been employed for graphene-filled polymeric nanomaterials. Intrinsic physical properties of nanocomposite depend on graphene modification and dispersion techniques. Polymer/graphene nanocomposite may have multifunctional characteristics due to synergistic effect of polymer/graphene. The article mainly discusses nanocomposite with potential uses in soldierly applications including flame resistance, ballistic protection, electromagnetic interference shielding, electrostatic-charge dissipation, sensors, corrosion protection, fuel cell, batteries, etc. The gestalt of defense applications of polymer/graphene nanocomposite may offer future perspective to develop promising materials.

scholarly journals Electrical and Thermal Conductivity of Cyclic Natural Rubber/Graphene Nanocomposite Prepared by Solution Mixing Technique

2020 ◽  
Vol 20 (4) ◽  
pp. 801
Author(s):  
Vivi Purwandari ◽  
Saharman Gea ◽  
Basuki Wirjosentono ◽  
Agus Haryono ◽  
I Putu Mahendra ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Natural Rubber ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modification Method ◽  
Ft Ir ◽  
Graphene Nanocomposite ◽  
Mk Analysis ◽  
Cetrimonium Bromide

Thermal and electrical conductivity studies of Cyclic Natural Rubber nanocomposite with graphene 1 and 2 phr (G1 and G2) and modified 1 and 2 graphenes (mG1 and mG2) have been carried out. Graphene was activated with cetrimonium bromide (CTAB), was isolated from Sawahlunto coal (Bb) by the Hummer modification method. The nanocomposite was fabricated through the mixing solution method using Xylena as a solvent. The characterizations of nanocomposites which were performed by Fourier Transform Infrared (FT-IR) and X-Ray Diffraction (XRD) reveals an interaction between graphene, CTAB and the CNR matrix. Furthermore, Scanning Electron Magnetic (SEM) and Transmission Electron Microscopy (TEM) indicate the particle size to be smaller and particle distribution is more in accordance with CTAB. Thermal analysis of nanocomposites using Differential Scanning Calorimeter (DSC) showed an increase in thermal conductivity from 3.0084 W/mK to 3.5569 W/mK. Analysis of electrical conductivity using the Two-Point Probe shows 2 phr mG (mG2) capable of increasing electrical conductivity from 0.1170 × 10–4 S/cm to 0.2994 × 10-4 S/cm.

COPPER ALLOY No. 815

Alloy Digest ◽  
1977 ◽  
Vol 26 (5) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Chromium Alloy ◽  
High Electrical Conductivity ◽  
Medium Hardness ◽  
Hardened Condition

Abstract Copper Alloy No. 815 is an age-hardenable cast copper-chromium alloy. It is characterized by high electrical and thermal conductivities combined with medium hardness and strength in the age-hardened condition. It is used for components requiring high electrical conductivity or high thermal conductivity. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Cu-332. Producer or source: Copper alloy foundries.

A Novel Poly(Ionic Liquid) as the Thermal Insulating Material

2020 ◽  
Vol 13 (3) ◽  
pp. 241-247
Author(s):  
Wenxin Wei ◽  
Guifeng Ma ◽  
Hongtao Wang ◽  
Jun Li
Keyword(s):  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flame Resistance ◽  
Insulating Material ◽  
Low Thermal Conductivity ◽  
Thermal Insulating ◽  
Poly Ionic Liquid

Objective: A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange reaction, and free radical polymerization. Then a series of the PIL were synthesized at different conditions. Methods: The specific heat capacity, glass-transition temperature and melting temperature of the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities of the PILs were measured by the laser flash analysis method. Results: Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of 421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1 K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane thermal insulating material although the latter had a much lower density. Conclusion: In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously increase the Oxygen Index, revealing its efficient flame resistance. Therefore, P[VBTPP][PF6] is a potential thermal insulating material.

Synergetic integration of thermal conductivity and flame resistance in nacre‐like nanocellulose composites

2021 ◽  
Vol 264 ◽  
pp. 118058
Author(s):  
Dechao Hu ◽  
Huaqing Liu ◽  
Yong Ding ◽  
Wenshi Ma
Keyword(s):  
Thermal Conductivity ◽  
Flame Resistance

scholarly journals Sigmoidal Dependence of Electrical Conductivity of Thin PEDOT:PSS Films on Concentration of Linear Glycols as a Processing Additive

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1975
Author(s):  
Hyeok Jo Jeong ◽  
Hong Jang ◽  
Taemin Kim ◽  
Taeshik Earmme ◽  
Felix Sunjoo Kim
Keyword(s):  
Electrical Conductivity ◽  
Ethylene Glycol ◽  
Triethylene Glycol ◽  
Optical Transmittance ◽  
Monomethyl Ether ◽  
Additive Concentration ◽  
Transparent Electrodes ◽  
Ethylene Glycol Monomethyl Ether ◽  
Conductivity Enhancement ◽  
Poly Styrene Sulfonate

We investigate the sigmoidal concentration dependence of electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) processed with linear glycol-based additives such as ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), hexaethylene glycol (HEG), and ethylene glycol monomethyl ether (EGME). We observe that a sharp transition of conductivity occurs at the additive concentration of ~0.6 wt.%. EG, DEG, and TEG are effective in conductivity enhancement, showing the saturation conductivities of 271.8, 325.4, and 326.2 S/cm, respectively. Optical transmittance and photoelectron spectroscopic features are rather invariant when the glycols are used as an additive. Two different figures of merit, calculated from both sheet resistance and optical transmittance to describe the performance of the transparent electrodes, indicate that both DEG and TEG are two most effective additives among the series in fabrication of transparent electrodes based on PEDOT:PSS films with a thickness of ~50–60 nm.

Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substitution Effect ◽  
Dimensionless Figure Of Merit ◽  
The Matrix ◽  
Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites

2021 ◽  
pp. 108128652110214
Author(s):  
Xiaodong Xia ◽  
George J. Weng
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Nanocomposites ◽  
Electromagnetic Interference ◽  
Effective Medium Theory ◽  
Scale Model ◽  
Shielding Effectiveness ◽  
Emi Shielding

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.

Thermal stable honokiol-derived epoxy resin with reinforced thermal conductivity, dielectric properties and flame resistance

2021 ◽  
Vol 412 ◽  
pp. 128647
Author(s):  
Jingjing Meng ◽  
Pengfei Chen ◽  
Rui Yang ◽  
Linli Dai ◽  
Cheng Yao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Properties ◽  
Epoxy Resin ◽  
Flame Resistance ◽  
Thermal Stable

scholarly journals Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Caroline O’Keeffe ◽  
Laura Rhian Pickard ◽  
Juan Cao ◽  
Giuliano Allegri ◽  
Ivana K. Partridge ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Fibre ◽  
Electromagnetic Interference ◽  
Design Tool ◽  
Electrically Conductive ◽  
Current Collection ◽  
Wide Range ◽  
Predictive Design ◽  
The Right ◽  
Metal Wires

AbstractConventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.

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