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Journal ArticleDOI: 10.1039/D0TA11040J

Flexible, multifunctional, and thermally conductive nylon/graphene nanoplatelet composite papers with excellent EMI shielding performance, improved hydrophobicity and flame resistance

02 Mar 2021-Journal of Materials Chemistry (Royal Society of Chemistry (RSC))-Vol. 9, Iss: 8, pp 5033-5044
Abstract: Composites with high thermal conductivity and excellent electromagnetic interference (EMI) shielding performance are in urgent demand in the fields of wireless communication technologies and portable intelligent electronic devices. However, it remains a great challenge to simultaneously improve thermal conductivity and EMI shielding effectiveness (SE) for polymer composites. This work reports a feasible and scaled method relating to vacuum-assisted filtration and compression-molding to fabricate nylon/graphene nanoplatelet (GNP) composite papers using commercial nylon gauze and GNPs. The results show that the composite papers exhibit good flexibility and multifunctional performances. At 11.8 wt% GNPs, the three-layered composite nylon/GNP paper, which had a thickness of about 180 μm, showed high thermal and electrical conductivities of 15.8 W m−1 K−1 and 24.3 S cm−1, respectively, and an outstanding EMI SE of 58.1 dB at the X-band (8.2–12.4 GHz). The compromise of thermal conductivity and EMI SE of the composite paper is much greater than that of other multifunctional composites reported in the literature. Specifically, the composite papers also show greatly enhanced hydrophobicity and flame resistance and satisfactory mechanical properties. To sum up, this work paves the way for the real engineering application of nylon-based composite papers in next-generation electronic devices.

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Topics: Composite number (52%)

5 results found

Journal ArticleDOI: 10.1016/J.COCO.2021.100879
Hongtao Guo1, Yang Li2, Yuan Ji1, Yiming Chen1  +6 moreInstitutions (4)
Abstract: Efficient electromagnetic interference (EMI) shielding materials with high flexibility, thin thickness, excellent mechanical property, and superior EMI shielding performance are urgently needed for modern electronic devices in areas of aerospace, military, and wireless communication systems. Herein, highly flexible multi-walled carbon nanotubes (MWCNTs)/aramid fibers (ANFs) composite papers with ordered and layered structures were successfully fabricated via a facile vacuum-assisted filtration. The obtained composite papers exhibited high electrical conductivity , outstanding mechanical property, excellent EMI shielding performance of 41.7 dB at a low density of 0.7–0.8 g cm −3 and an average thickness of 0.3 mm. A parameter of the specific shielding effectiveness/thickness (SSE/t) was as high as 2395.8 dB cm2 g−1, which was benefited from the layer structures and the formation of conductive networks inside composite papers. It is expected to provide a promising strategy to prepare high-performance nanocomposite papers for EMI shielding in the field of artificial intelligence or smart and wearable electronics.

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2 Citations

Open accessJournal ArticleDOI: 10.1016/J.JMRT.2021.11.050
Yanting Wang1, Ting-Ting Li1, Bing-Chiuan Shiu2, Xuefei Zhang1  +3 moreInstitutions (2)
Abstract: With the rapid development of wearable electronic products and smart devices, there is an urgent need to develop efficient electromagnetic interference (EMI)shielding materials to eliminate the resulting radiation pollution. Herein, hydrophobic and multi-responsive conductive composite film with core-shell structure and sandwich structure are constructed via simple in-situ polymerization and dip coating methods. The thin silicone coating can enhance the bonding fastness of the substrate and the conductive functional layer and endow the composite film excellent waterproof performance. The composite film with a thickness of 45μm exhibits outstanding electrical conductivity of 62.15 S/cm and EMI shielding effectiveness (EMI SE) of 37.71dB. Surprisingly, the composite film also exhibits good waterproof performance and excellent electro-optical thermal response, and has good stability in complex environments. This work proves the advantages of constructing multiple conductive interfaces inside the nanofiber film, and provides a new preparation strategy for efficient multifunctional shielding materials, which is expected to be widely used in the next generation of wearable electronic devices and wearable smart clothing.

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Open accessJournal ArticleDOI: 10.1039/D1TA08147K
Kexia Jin1, Jianxiong Xing2, Xinge Liu, Jiang Zehui  +3 moreInstitutions (2)
Abstract: To achieve high mechanical strength electromagnetic interference (EMI) shielding materials for practical application, cellulose nanocrystals (CNC), as a reinforcing and dispersing agent, are intercalated into reduced graphene oxide (RGO) layers, forming an ultrathin, robust, flexible, and hydrophobic CNC/RGO film with a highly ordered nacre-like layered structure via a self-assembly process. The layered structure significantly shortens the reduction time and improves the mechanical strength and shielding effectiveness (SE) of the resultant CNC/RGO composite film. The controlled preparation of CNC with different aspect ratios is realized by using separated bamboo fiber and parenchyma. The CNC of the fiber with a higher aspect ratio and lower diameter results in a lower porosity, denser structure, and more uniform distribution in the composites, and therefore a higher electrical conductivity and SE. The highest SE (39.1 dB) and specific SE (11 367 dB cm2 g−1) with a high tensile strength (179 MPa) and water contact angle (106°) of the CNC/RGO film are obtained at 10 wt% CNC loading with a film thickness of 12 μm. The maximum tensile strength of the composite film reaches 227 MPa with 30–50% CNC. The ultrathin high-performance CNC/RGO film shows significant potential as an EMI shielding material in the aerospace and flexible electronics fields.

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Journal ArticleDOI: 10.1016/J.COCO.2021.100977
Wen-yan Wang1, Xiao Ma1, Jing-hui Yang1, Xiao-dong Qi1  +2 moreInstitutions (1)
Abstract: Fabricating the thermally conductive composites through incorporating fillers into polymer matrix is usually at the sacrifice of the fracture toughness. To resolve such contradiction, this work proposed a feasible but highly efficient method of constructing the thermally conductive path in the epoxy composite at extremely low filler content. The polyvinylpyrrolidone (PVP) modified carbon nanofibers (P-CNFs) were coated on the three-dimensional (3D) framework surface of the melamine foam (MF), then the epoxy resin was impregnated into the MF@P–CNF. The results showed that the assembled structure of MF@P-CNFs could be well reserved in the epoxy composite. Consequently, at extremely low P–CNF content (0.8 wt%), the MF@P–CNF/EP sample shows the largely enhanced thermal conductivity (0.4 W/m·K) and glass transition temperature (167 °C) compared with the pure epoxy sample (0.2 W/m·K and 162 °C). Specifically, the composite sample also shows the apparently enhanced fracture toughness. Therefore, it is believed that coating CNFs on the 3D interconnected framework of MF is a promising way to prepare the epoxy composites with good comprehensive properties.

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Topics: Epoxy (58%), Melamine foam (55%), Carbon nanofiber (53%) ... show more

Journal ArticleDOI: 10.1039/D1TA07057F
Wen-yan Wang1, Chen-yu Li1, Xiao-dong Qi1, Jing-hui Yang1  +1 moreInstitutions (1)
Abstract: The mechanical properties of thermally conductive composites are the key to realize their applications. Strength of materials is of significance, furthermore the toughness of materials also should attract more concern. Actually, few researchers have reported the simultaneous improvement of strength and toughness of anisotropic thermally and electrically conductive composites. Therefore, this study aims to obviously improve the in-plane thermal and electrical conductivities of nylon composites, which display superior tensile strength and toughness, compared to other thermally conductive composites. The nylon composite papers, prepared through a facile method involving vacuum-assisted filtration and compression molding processes, present a laminate structure and compact graphene nanoplatelet (GNP) stacks inside composites. On account of the special structure, the nylon composite papers show a super-high in-plane thermal conductivity of 16.0 W m−1 K−1 and electrical conductivity of 18.0 S cm−1 at a filler loading of 14.6 wt%. Surprisingly, the composite papers still exhibit a high strength of 48.3 MPa, which is comparable to that of a pure nylon film. In addition, the elongation at break of the composite paper with 14.6 wt% GNPs is as high as 34.2%, ultimately endowing the composite papers with a good toughness of 13.15 MJ m−3. The nylon composite papers successfully achieve the integration of excellent thermal and electrical conductivities, and superior strength and toughness, showing huge application values in the field of intelligent electronic device.

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Topics: Toughness (57%), Ultimate tensile strength (56%), Composite number (54%) ... show more

84 results found

Journal ArticleDOI: 10.1021/NN1006368
22 Jul 2010-ACS Nano
Abstract: An improved method for the preparation of graphene oxide (GO) is described. Currently, Hummers’ method (KMnO4, NaNO3, H2SO4) is the most common method used for preparing graphene oxide. We have found that excluding the NaNO3, increasing the amount of KMnO4, and performing the reaction in a 9:1 mixture of H2SO4/H3PO4 improves the efficiency of the oxidation process. This improved method provides a greater amount of hydrophilic oxidized graphene material as compared to Hummers’ method or Hummers’ method with additional KMnO4. Moreover, even though the GO produced by our method is more oxidized than that prepared by Hummers’ method, when both are reduced in the same chamber with hydrazine, chemically converted graphene (CCG) produced from this new method is equivalent in its electrical conductivity. In contrast to Hummers’ method, the new method does not generate toxic gas and the temperature is easily controlled. This improved synthesis of GO may be important for large-scale production of GO as well as the ...

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Topics: Graphene oxide paper (60%), Graphene (52%)

8,351 Citations

Journal ArticleDOI: 10.1038/NATURE11458
11 Oct 2012-Nature
Abstract: Recent years have witnessed many breakthroughs in research on graphene (the first two-dimensional atomic crystal) as well as a significant advance in the mass production of this material. This one-atom-thick fabric of carbon uniquely combines extreme mechanical strength, exceptionally high electronic and thermal conductivities, impermeability to gases, as well as many other supreme properties, all of which make it highly attractive for numerous applications. Here we review recent progress in graphene research and in the development of production methods, and critically analyse the feasibility of various graphene applications.

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Topics: Graphene nanoribbons (58%), Bilayer graphene (55%), Graphene (52%)

6,902 Citations

Open accessJournal ArticleDOI: 10.1038/NMAT3064
Alexander A. Balandin1Institutions (1)
01 Aug 2011-Nature Materials
Abstract: Recent years have seen a rapid growth of interest by the scientific and engineering communities in the thermal properties of materials. Heat removal has become a crucial issue for continuing progress in the electronic industry, and thermal conduction in low-dimensional structures has revealed truly intriguing features. Carbon allotropes and their derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range--of over five orders of magnitude--from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. Here, I review the thermal properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. Special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe the prospects of applications of graphene and carbon materials for thermal management of electronics.

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Topics: Carbon nanotube (67%), Graphene (61%), Carbon (58%) ... show more

4,485 Citations

Open accessJournal ArticleDOI: 10.1038/NMAT3064
Alexander A. Balandin1Institutions (1)
Abstract: Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range – of over five orders of magnitude – from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.

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Topics: Carbon nanotube (70%), Graphene (63%), Carbon (62%) ... show more

3,609 Citations

Journal ArticleDOI: 10.1016/J.PROGPOLYMSCI.2010.07.005
Tapas Kuilla1, Sambhu Bhadra2, Dahu Yao1, Nam Hoon Kim1  +2 moreInstitutions (2)
Abstract: This paper reviews recent advances in the modification of graphene and the fabrication of graphene-based polymer nanocomposites. Recently, graphene has attracted both academic and industrial interest because it can produce a dramatic improvement in properties at very low filler content. The modification of graphene/graphene oxide and the utilization of these materials in the fabrication of nanocomposites with different polymer matrixes have been explored. Different organic polymers have been used to fabricate graphene filled polymer nanocomposites by a range of methods. In the case of modified graphene-based polymer nanocomposites, the percolation threshold can be achieved at a very lower filler loading. Herein, the structure, preparation and properties of polymer/graphene nanocomposites are discussed in general along with detailed examples drawn from the scientific literature.

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Topics: Graphene (59%), Polymer nanocomposite (57%)

2,749 Citations