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1.
Yuqiang Zeng Tian Li Yonggang Yao Tangyuan Li Liangbing Hu Amy Marconnet 《Advanced functional materials》2019,29(27)
Reduced graphene oxide (RGO) films are promising in applications ranging from electronics to flexible sensors. Though high electrical and thermal conductivities have been reported for RGO films, existing thermal conductivity data for RGO films show large variations from 30 to 2600 W m?1 K?1. Further, there is a lack of data at low temperatures (<300 K), which is critical for the understanding of thermal transport mechanisms. In this work, a temperature‐dependent study of thermal (10–300 K) and electrical (10–3000 K) transport in annealed RGO films indicates the potential application of RGO films for sensing temperatures across an extremely wide range. The room‐temperature thermal conductivity increases significantly from 46.1 to 118.7 W m?1 K?1 with increasing annealing temperature from 1000 to 3000 K with a corresponding increase in the electrical conductivity from 5.2 to 1481.0 S cm?1. In addition, films reduced at 3000 K are promising for sensing extreme temperatures as demonstrated through the measured electrical resistivity from 10 to 3000 K. Sensors based on RGO films are advantageous over conventional temperature sensors due to the wide temperature range and flexibility. Thus, this material is useful in many applications including flexible electronics and thermal management systems. 相似文献
2.
Chao Teng Dan Xie Jianfeng Wang Zhi Yang Guangyuan Ren Ying Zhu 《Advanced functional materials》2017,27(20)
Due to low density, extremely high electrical and thermal conductivities, graphene has great potential to construct lightweight thermal conductive paper for high‐power electric devices. However, the remarkable properties of graphene are on a molecular level and difficult to achieve when processed into macroscopic paper. Here, an effective route to construct ultrahigh conductive graphene paper is developed. First, large‐volume, high‐concentration, plane‐defect‐free, few‐layer graphene dispersion is fast produced from graphite at high yield through ball milling. The exfoliated graphene dispersion is further processed into graphene paper through fast filtration, thermal treatment, and mechanical compression. The electrical and thermal conductivities of the resultant graphene paper are as high as 2231 S cm?1 and 1529 W m?1 K?1, superior to previously reported graphene papers. Structural analyses confirm that the ultrahigh conductivities are attributed to high quality of graphene sheets, their compact ordered stacking, and large graphitic crystalline domain size, which improve electron and phonon transport within basal plane of graphene sheet and between graphene sheets. 相似文献
3.
Ji Liu Zhangshuo Liu Hao‐Bin Zhang Wei Chen Zhenfang Zhao Qi‐Wei Wang Zhong‐Zhen Yu 《Advanced Electronic Materials》2020,6(1)
Ultrathin and flexible electromagnetic interference (EMI) shielding materials are urgently required to shield increasingly serious radiation pollution. Newly emerged 2‐dimensional transition‐metal carbides (MXenes) are promising for efficient EMI shielding due to their superb electrical conductivity, versatile surface chemistry, and layered structure. However, the mechanical performance of MXene films is not satisfactory for engineering applications, and the traditional reinforcement approaches usually cause serious reduction in electrical conductivity of the films. An efficient strategy is demonstrated to reinforce MXene films with graphene oxide, leading to enhanced interfacial interactions and more densely packed layered structures. The modified MXene film exhibits a high tensile strength of 209 MPa while maintaining its high electrical conductivity close to that of pristine MXene film. An outstanding shielding effectiveness of 50.2 dB is achieved at a small film thickness of 7 µm. Moreover, a facile technique is used to tune the wetting behavior of the modified MXene films. The water contact angle can be readily regulated from 65.7° to 95.7°. This film, with excellent EMI shielding performance and tunable wetting behavior, is highly promising for various applications in aerospace, flexible supercapacitors, and smart electronics. 相似文献
4.
Ding‐Xiang Yan Huan Pang Bo Li Robert Vajtai Ling Xu Peng‐Gang Ren Jian‐Hua Wang Zhong‐Ming Li 《Advanced functional materials》2015,25(4):559-566
A high‐performance electromagnetic interference shielding composite based on reduced graphene oxide (rGO) and polystyrene (PS) is realized via high‐pressure solid‐phase compression molding. Superior shielding effectiveness of 45.1 dB, the highest value among rGO based polymer composite, is achieved with only 3.47 vol% rGO loading owning to multi‐facet segregated architecture with rGO selectively located on the boundaries among PS multi‐facets. This special architecture not only provides many interfaces to absorb the electromagnetic waves, but also dramatically reduces the loading of rGO by confining the rGO at the interfaces. Moreover, the mechanical strength of the segregated composite is dramatically enhanced using high pressure at 350 MPa, overcoming the major disadvantage of the composite made by conventional‐pressure (5 MPa). The composite prepared by the higher pressure shows 94% and 40% increment in compressive strength and compressive modulus, respectively. These results demonstrate a promising method to fabricate an economical, robust, and highly efficient EMI shielding material. 相似文献
5.
Mengxiong Liu Yuyao Yang Ruojuan Liu Kun Wang Shuting Cheng Hao Yuan Kewen Huang Fushun Liang Fan Yang Kangyi Zheng Longfei Liu Ce Tu Jingnan Wang Xuzhao Gai Wang Qiao Xiaobai Wang Yue Qi Zhongfan Liu 《Advanced functional materials》2024,34(49):2409379
Graphene-skinned fiber fabric is prepared by chemical vapor deposition (CVD) of continuous graphene on fabric, which enables conformal graphene coverage on fibers and inherits high electrical and thermal conductivity of graphene. However, in the fabric-shaped configuration, high electrical and thermal contact resistances between fibers, and the lack of conductive and thermal pathways along radial direction of fibers limit the improvement of electrical and thermal conductivity. Herein, carbon nanotubes (CNTs), due to the 1D structure with excellent electrical and thermal conductivity, are introduced to build rich “bridges” to connect the isolated fibers to build new electron and phonon transport channels. Thus, the conceptual design of CNT/graphene-skinned glass fiber fabric (CNT/GGFF) is creatively proposed and realized by a carefully designed CVD. Constructing the 3D electrically and thermally conductive network in CNT/GGFF leads to >90% decrease of sheet resistance, 4.5 times increase of tensile strength, and >70% decrease of thermal resistance compared with GGFF, making it promising for applications in composite materials, heat dissipation, and de-icing. Moreover, the thermal resistance of CNT/GGFF exhibits temperature-independent, extending applications to aviation and space because changes in thermal conductivity of traditional materials with environmental temperatures can adversely affect the thermal stability, reliability, and lifetime of aircrafts. 相似文献
6.
Mohammad Razaul Karim Hideaki Shinoda Mina Nakai Kazuto Hatakeyama Hidenobu Kamihata Takeshi Matsui Takaaki Taniguchi Michio Koinuma Keita Kuroiwa Mohamedally Kurmoo Yasumichi Matsumoto Shinya Hayami 《Advanced functional materials》2013,23(3):323-332
The rare coexistence of ferromagnetism and electrical conductivity is observed in the reduced graphene oxide–metal oxide hybrids, rGO‐Co, rGO‐Ni, and rGO‐Fe, using chemical reduction with hydrazine or ultraviolet photoirradiation of the graphene oxide–metal complexes, GO‐Co, GO‐Ni, and GO‐Fe. The starting and final materials are characterized by X‐ray photoelectron spectroscopy, transmission electron microscopy (TEM), elemental analysis, Mössbauer spectroscopy, and Raman spectroscopy. In contrast to graphene, where the electrical conductivity and magnetic properties are controlled by carrier (electron or hole) doping, those of graphene oxide can be controlled by complexation with Co2+, Ni2+, and Fe3+ cations through the strong electrostatic affinity of negatively charged graphene oxide towards metal cations. The presence of ferromagnetism and electrical conductivity in these hybrids can promote significant applications including magnetic switching and data storage. 相似文献
7.
Atsuko Kosuga Ken Kurosaki Kunio Yubuta Anek Charoenphakdee Shinsuke Yamanaka Ryoji Funahashi 《Journal of Electronic Materials》2009,38(7):1303-1308
We have focused on the recently reported nanostructured bulk ZnMn2−x Ga x O4 to evaluate whether this type of nanostructured oxide can effectively reduce thermal conductivity. Firstly, powdered samples of ZnMn2−x Ga x O4 (x = 0 to 2) were prepared and the effect of heat treatment on the obtained phases was examined. Secondly, we have picked out the composition of ZnMnGaO4, in which two distinct types of rectangular nanorods with different compositions spontaneously interlace to form a cross-sectional checkerboard pattern. To confirm the effect of nanostructure on thermal transport properties, the room-temperature thermal conductivity of this nanostructured oxide was evaluated. 相似文献
8.
Liu Zulan Li Zhi Cheng Lan Chen Sihao Wu Dayang Dai Fangyin 《Advanced Electronic Materials》2019,5(4)
The desire for this lightweight and flexible electronics has grown increasingly, and the flexible and wearable electronic textiles can be realized by coating traditional textiles with conductive materials. Here, the conductive silk fabrics are prepared by coating graphene oxide (GO) onto silk fabrics and followed by thermal reduction. The scanning electron microscope results show that the GO coated onto silk fabrics successfully forms a continuous thin film. The oxygen functional groups are removed by thermal reduction. The main structure (β‐sheet structure) of silk fabrics is not destroyed through a series of treatment, guaranteeing good mechanical properties. The resistivity and conductivity of silk fabrics using regenerated silk fibroin as a glue can reach 3.28 KΩ cm−1, 3.06 × 10−4 S cm−1 respectively, which can meet the electron conductive requirement of wearable electronics. Thus, it can be used for sensors, portable devices, and wearable electronic textiles. 相似文献
9.
S. Stefanoski L. N. Reshetova A. V. Shevelkov G. S. Nolas 《Journal of Electronic Materials》2009,38(7):985-989
We report on temperature-dependent thermal conductivity, resistivity, and Seebeck coefficient of two polycrystalline Br-containing
Sn-clathrate compounds with the type I crystal structure. Interstitial Br atoms reside inside the polyhedral cavities formed
by the framework, resulting in hole conduction. The framework bonding directly influences the transport properties of these
two compositions. The transport properties of these two clathrates are compared with those of other Sn-clathrates. We also
discuss our results in terms of the potential for thermoelectric applications. 相似文献
10.
G.S. Nolas X. Lin J. Martin M. Beekman H. Wang 《Journal of Electronic Materials》2009,38(7):1052-1055
There are a large number of inorganic compounds with open-framework structures that entrap atoms or molecules within the lattice. Of these, the skutterudites and type I clathrates have gained the greatest attention from the perspective of thermoelectric applications. The crystal structure of these materials can be considered as being open in the sense that they possess voids whereby interstitially placed atoms are bounded loosely, thereby creating localized disorder in an otherwise well-ordered, covalently bonded lattice. The optimum situation occurs if the intrinsic mobility is relatively high due to the well-ordered, periodic structure of the crystal framework while the phonons are scattered by localized disorder. Substantial experimental and theoretical research has been devoted to these two material systems over the past decade. This effort has shown that the physical properties are directly related to their unique crystal structures, as well as the different compositions that can be synthesized in order to modify these physical properties. 相似文献
11.
Izzuddin Zaman Hsu‐Chiang Kuan Qingshi Meng Andrew Michelmore Nobuyuki Kawashima Terry Pitt Liqun Zhang Sherif Gouda Lee Luong Jun Ma 《Advanced functional materials》2012,22(13):2735-2743
A scalable approach for the mass production of chemically modified graphene has yet to be developed, which holds the key to the large‐scale production of stable graphene colloids for optical electronics, energy conversion, and storage materials, catalysis, sensors, composites, etc. Here, a facile approach to fabricating covalently modified graphene and its polymer nanocomposites is presented. The method involves: i) employing a common furnace, rather than a furnace installed with a quartz tube and operated in inert gas as required in previous studies, to treat a commercial graphite intercalation compound with thermal shocking and ultrasonication and fabricate graphene platelets (GnPs) with a thickness of 2.51 ± 0.39 nm that contain only 7 at% oxygen; ii) grafting these GnPs with a commercial, long‐chain surfactant, which is able to create molecular entanglement with polymer matrixes by taking advantage of the reactions between the epoxide groups of the platelets and the end amine groups of the surfactant, to produce chemically modified graphene platelets (m‐ GnPs); and iii) solution‐mixing m‐GnPs with a commonly used polymer to fabricate nanocomposites. These m‐GnPs are well dispersed in a polymer with highly improved mechanical properties and a low percolation threshold of electrical conductivity at 0.25 vol%. This novel approach could lead to the future scalable production of graphene and its nanocomposites. 相似文献
12.
Mu Cao Ding‐Bang Xiong Li Yang Shuaishuai Li Yiqun Xie Qiang Guo Zhiqiang Li Horst Adams Jiajun Gu Tongxiang Fan Xiaohui Zhang Di Zhang 《Advanced functional materials》2019,29(17)
Highly efficient conductors are strongly desired because they can lead to higher working performance and less energy consumption in their wide range applications. However, the improvements on the electrical conductivities of conventional conductors are limited, such as purification and growing single crystal of metals. Here, by embedding graphene in metals (Cu, Al, and Ag), the trade‐off between carrier mobility and carrier density is surmount in graphene, and realize high electron mobility and high electron density simultaneously through elaborate interface design and morphology control. As a result, a maximum electrical conductivity three orders of magnitude higher than the highest on record (more than 3,000 times higher than that of Cu) is obtained in such embedded graphene. As a result, using the graphene as reinforcement, an electrical conductivity as high as ≈117% of the International Annealed Copper Standard and significantly higher than that of Ag is achieved in bulk graphene/Cu composites with an extremely low graphene volume fraction of only 0.008%. The results are of significance when enhancing efficiency and saving energy in electrical and electronic applications of metals, and also of interest for fundamental researches on electron behaviors in graphene. 相似文献
13.
An ex situ strategy for fabrication of graphene oxide (GO)/metal oxide hybrids without assistance of surfactant is introduced. Guided by this strategy, GO/Al2O3 hybrids are fabricated by two kinds of titration methods in which GO and Al2O3 colloids are utilized as titrant for hybrids of low and high GO content respectively. After sintered by spark plasma sintering, few‐layer graphene (FG)/Al2O3 nanocomposites are obtained and GO is well reduced to FG simultaneously. A percolation threshold as low as 0.38 vol.% is achieved and the electrical conductivity surpasses 103 Sm?1 when FG content is only 2.35 vol.% in FG/Al2O3 composite, revealing the homogeneous dispersion and high quality of as‐prepared FG. Furthermore, it is found that the charge carrier type changes from p‐ to n‐type as graphene content becomes higher. It is deduced that this conversion is related to the doping effect induced by Al2O3 matrix and is thickness‐dependent with respect to FG. 相似文献
14.
Fariborz Kargar Zahra Barani Michael Balinskiy Andres Sanchez Magana Jacob S. Lewis Alexander A. Balandin 《Advanced Electronic Materials》2019,5(1)
The synthesis and characterization of epoxy‐based composites with few‐layer graphene fillers, which are capable of dual‐functional applications, are reported. It is found that composites with certain types of few‐layer graphene fillers reveal an efficient total electromagnetic interference shielding, SEtot ≈ 45 dB, in the important X‐band frequency range, f = 8.2 −12.4 GHz, while simultaneously providing high thermal conductivity, K ≈ 8 W m−1 K−1, which is a factor of ×35 larger than that of the base matrix material. The efficiency of the dual‐functional application depends on the filler characteristics: thickness, lateral dimensions, aspect ratio, and concentration. Graphene loading fractions above the electrical and thermal “percolation thresholds” allow for strong enhancement of both the electromagnetic interference shielding and heat conduction properties. Interestingly, graphene composites can block the electromagnetic energy even below the electrical percolation threshold, remaining electrically insulating, which is an important feature for some types of thermal interface materials. The dual functionality of the graphene composites can substantially improve the electromagnetic shielding and thermal management of airborne systems while simultaneously reducing their weight and cost. 相似文献
15.
16.
David Tilve-Martinez Wilfrid Neri Dylan Horaud Nicolas Vukadinovic Benoit Berton Arnaud Desmedt Jinkai Yuan Philippe Poulin 《Advanced functional materials》2023,33(21):2214954
Digital Light Processing (DLP) allows the fast realization of 3D objects with high spatial resolution. However, DLP is limited to transparent resins, and therefore not well suited for printing electrically conductive materials. Manufacturing conductive materials will significantly broaden the spectrum of applications of the DLP technology. But conductive metals or carbon-based fillers absorb and scatter light; inhibiting thereby photopolymerization, and lowering resolution. In this study, UV transparent liquid crystal graphene oxide (GO) is used as precursor for generating in situ conductive particles. The GO materials are added to a photopolymerizable resin via an original solvent exchange process. By contrast to earlier contributions, the absence of drying during the all process allows the GO material to be transferred as monolayers to limit UV scattering. The absence of UV scattering and absorption allows for fast and high-resolution 3D printing. The chosen resin sustain high temperature to enable an in situ efficient thermal reduction of GO into reduced graphene oxide (rGO) that is electrically conductive. The rGO particles form percolated networks with conductivities up to 1.2 × 10−2 S m−1. The present method appears therefore as a way to reconcile the DLP technology with the manufacturing of 3D electrically conductive objects. 相似文献
17.
Ramesh Chandra Mallik Christian Stiewe Gabriele Karpinski Ralf Hassdorf Eckhard Müller 《Journal of Electronic Materials》2009,38(7):1337-1343
The properties of Co4Sb12 with various In additions were studied. X-ray diffraction revealed the presence of the pure δ-phase of In0.16Co4Sb12, whereas impurity phases (γ-CoSb2 and InSb) appeared for x = 0.25, 0.40, 0.80, and 1.20. The homogeneity and morphology of the samples were observed by Seebeck microprobe and scanning
electron microscopy, respectively. All the quenched ingots from which the studied samples were cut were inhomogeneous in the
axial direction. The temperature dependence of the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ) was measured from room temperature up to 673 K. The Seebeck coefficient of all In-added Co4Sb12 materials was negative. When the filler concentration increases, the Seebeck coefficient decreases. The samples with In additions
above the filling limit (x = 0.22) show an even lower Seebeck coefficient due to the formation of secondary phases: InSb and CoSb2. The temperature variation of the electrical conductivity is semiconductor-like. The thermal conductivity of all the samples
decreases with temperature. The central region of the In0.4Co4Sb12 ingot shows the lowest thermal conductivity, probably due to the combined effect of (a) rattling due to maximum filling and
(b) the presence of a small amount of fine-dispersed secondary phases at the grain boundaries. Thus, regardless of the non-single-phase
morphology, a promising ZT (S
2
σT/κ) value of 0.96 at 673 K has been obtained with an In addition above the filling limit. 相似文献
18.
19.
Sahar Naghibi Fariborz Kargar Dylan Wright Chun Yu Tammy Huang Amirmahdi Mohammadzadeh Zahra Barani Ruben Salgado Alexander A. Balandin 《Advanced Electronic Materials》2020,6(4)
Development of next‐generation thermal interface materials (TIMs) with high thermal conductivity is important for thermal management and packaging of electronic devices. The synthesis and thermal conductivity measurements of noncuring thermal paste, i.e., grease, based on mineral oil with a mixture of graphene and few‐layer graphene flakes as the fillers, is reported. The graphene thermal paste exhibits a distinctive thermal percolation threshold with the thermal conductivity revealing a sublinear dependence on the filler loading. This behavior contrasts with the thermal conductivity of curing graphene TIMs, based on epoxy, where superlinear dependence on the filler loading is observed. The performance of the thermal paste is benchmarked against top‐of‐the‐line commercial thermal pastes. The obtained results show that noncuring graphene TIMs outperforms the best commercial pastes in terms of thermal conductivity, at substantially lower filler concentration of φ = 27 vol%. The obtained results shed light on thermal percolation mechanism in noncuring polymeric matrices laden with quasi‐two‐dimensional fillers. Considering recent progress in graphene production via liquid phase exfoliation and oxide reduction, the results open a pathway for large‐scale industrial application of graphene in thermal management of electronics. 相似文献
20.
Fei Zhang Yiyu Feng Mengmeng Qin Long Gao Zeyu Li Fulai Zhao Zhixing Zhang Feng Lv Wei Feng 《Advanced functional materials》2019,29(25)
Stress controllability in thermal and electrical conductivity is important for flexible piezoresistive devices. Due to the strength‐elasticity trade‐off, comprehensive investigation of stress‐controllable conduction in elastic high‐modulus polymers is challenging. Here presented is a 3D elastic graphene‐crosslinked carbon nanotube sponge/polyimide (Gw‐CNT/PI) nanocomposite. Graphene welding at the junction enables both phonon and electron transfer as well as avoids interfacial slippage during cyclic compression. The uniform Gw‐CNT/PI comprising a high‐modulus PI deposited on a porous templated network combines stress‐controllable thermal/electrical conductivity and cyclic elastic deformation. The uniform composites show different variation trends controlled by the porosity due to different phonon and electron conduction mechanisms. A relatively high k (3.24 W m?1 K?1, 1620% higher than PI) and suitable compressibility (16.5% under 1 MPa compression) enables the application of the composite in flexible elastic thermal interface conductors, which is further analyzed by finite element simulations. The interconnected network favors a high stress‐sensitive electrical conductivity (sensitivity, 973% at 9.6% strain). Thus, the Gw‐CNT/PI composite can be an important candidate material for piezoresistive sensors upon porosity optimization based on stress‐controllable thermal or electrical conductivity. The results provide insights toward controlling the stress‐induced thermal/electrical conductivities of 3D interconnected templated composite networks for piezoresistive conductors or sensors. 相似文献