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Tn this paper, different contents (0.25%, 0.5%, 0.75% and 1%) of graphene nanoplatelets (GNP) were used to modify epoxy resin adhesive. Through double-sided shear tests of carbon fiber reinforced concrete structures, the change of adhesive properties before and after GNP modification under different time of immersion aging (2, 4, 6, 8 weeks) was studied, and the influence of graphene nanoplatelets modification on the durability of adhesive joint was investigated. The test results show that both the interfacial bonding strength and the maximum slip displacement increase first and then decrease with the increase of GNP content under the nonimmersion and immersion aging tests, and 0.5% GNP has the largest increase rate for interfacial bonding strength under each working condition. After 8 weeks of immersion aging, ().5% GNP increases the bonding strength and maximum slip by 54.1 % and 53.66% respectively. After 8 weeks of aging, the bonding strength of unmodified adhesive decreases by 15.19% compared with the non-aging environment, while 0.5% GNIVEpoxy adhesive only decreases by 10.47%. The GNP reinforced adhesive could not only improve the adhesive joints strength, but also reduce the diffusion of water molecules into adhesive and interface. This paper provides some reference for the application of GNP reinforced adhesive to enhance durability of the carbon fiber bonded concrete structure. [ABSTRACT FROM AUTHOR]

Tn recent years, graphene/polyurethane nanocomposites have attracted much attention due to their superior comprehensive properties. Incorporating graphene or its derivatives into I〉U matrix could significantly improve the physical mechanical, thermal, electromagnetic and other properties, which meets the special requirements of high-performance and multi-functional polymer composites. Tn this paper, the functional modification methods of graphene nanosheets, including covalent modification and non-covalent modification were first introduced. Furthermore, the fabrication processes of graphene/poly urethane nanocomposites, including in-situ polymerization, solution blending, melt blending, aqueous (latex) blending, etc., were briefly introduced. The recent research progress of graphene/poly urethane composites in mechanical, electrical, dielectric, thermal, gas barrier, flame retardant, electromagnetic interference shielding and corrosion resistant properties were all reviewed in detail. The future challenges and development prospects of high-performance graphene/poly urethane nanocomposites were also prospected. [ABSTRACT FROM AUTHOR]

With the development of the power system, the power of its main electrical control equipment circuit breakers continues to increase. As the core component of circuit breakers, the research on electrical contact materials has received increasing attention. In this paper, Cu powder, Cr powder and graphene are used as raw materials. Graphene was added by mechanical mixing and chemical vapor deposition respectively. Graphene reinforced CuCr contacts were made by pressing-sintering-repressing-resintering process. The effects of different processes on the microstructure and properties of CuCr contacts were studied. It is found that the graphene added by chemical vapor deposition is evenly distributed in the matrix. The conductivity is increased to 40.64 MS/s, the average arcing time is 5.37 ms, and the welding force ranges from 13.550 to 13.636 N. The conductivity, welding resistance and ablation resistance have been significantly improved, which is beneficial to further expand its application range in the field of electrical contact materials. [ABSTRACT FROM AUTHOR]

Graphene is a single-layer two-dimensional honeycomb lattice structure with carbon as the basic atom through sp2 hybridization, TIC-TAC conjugation and light stacking, which has excellent physical and chemical proper ties and has become a hot research topic with excellent performance in several fields. Because of the large sheaf ice surface area of graphene, it can be used as a matrix, and the resulting graphene based composites are an important research direction in the field of graphene applications, which can be divided into loaded and reinforced types. This paper mainly reviews the preparation methods and application status of graphene loaded metal (monometallic, bimetallic and)/compound (metal oxide, metal sulfide and metal flounder) composites in recent years. Furthermore, by summarizing the above composites, it so concluded that Issues such as particle size and shape of the metal/compound, degree of dispersion, and stacking of graphene sheet layers affect the performance. It also provides an outlook on the application prospects of graphenetioaded metal/compound composites in the fields of magnetism, mechanics, microwave absorption, and thermal conductivity. [ABSTRACT FROM AUTHOR]

The wettability of graphene that makes graphene as a functionalized material has attracted widespread attention in the domain of surface engineering. This article starts from the fundamental simulation method for the wettability of graphene, and summarizes the effects on the wettability of graphene which contains defect structures, surface topography, aerial contaminations and so on. Based on the research about the analysis of graphene transparent wettability, the paper expounds the reason why the tendency of transparent wettability in graphene could be generated, and generalizes the research about the graphene transparent wettability. With the two different coating materials which is graphene and graphene oxide, this paper discusses the method to form the superhydrophobic graphene surface. Tn term of research and development status of functional surface wettability of graphene, some key scientific issues that are needed to be solved are proposed in this paper. The future study of wettability of graphene is also prospected in the end. [ABSTRACT FROM AUTHOR]

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The all-solid-state lithium battery has the advantages of high safety and reliability, high energy density, long cycle life, wide electrochemical window, and good high temperature adaptability. However, the main bottleneck restricting its practical application lies in the interface between the electrode and the solid electrolyte, such as Li dendrites and volume expansion in the anode interface region, as well as structural changes, space charge layer and side reactions in the cathode interface region. Graphene is widely used in the field of electrochemical energy storage due to its special 2D structure, excellent electrical conductivity, thermal conductivity and mechanical properties. In this paper, the authors review the research progress on the modification of electrode/solid electrolyte interface with graphene, and prospect the application of graphene in solid-state batteries. [ABSTRACT FROM AUTHOR]

In this paper, considering the non-harmonic oscillation of atoms, the theory and method of solid state physics were used. The dependence of free energy and low temperature heat capacity of graphene on temperature was determined, and the influence of atomic anharmonic vibration on them was discussed. The results show that the free energy of characteristic function of graphene was related to the anharmonic coefficient of atomic vibration. The thermal capacity of graphene was much larger than that of ordinary heat storage materials, and the value of graphene increased non-linearly with the increase of temperature. When the temperature was very low ((4.84 ± 0.44) x 10³-(5.30 ± 0.48) x 10³ W/(m · K), the change rule obeyed (4.84 ± 0.44) x 10³ (5.30 ± 0.48) x 10³ W/(m · K). When the temperature was not too high ((4.84 ± 0.44) x 10³-(5.30 ± 0.48) x 10³ W/(m · K), the change was faster. When the temperature was higher ((4.84 ± 0.44) x 10³-(5.30 ± 0.48) x 10³ W/(m · K), the change was slower. The influence of the anharmonic effect on the heat capacity of the graphene was increased with the increase of the temperature. The basic rules for the study of anharmonic effect of solid materials presented in this paper were effective to the study of the variation of the thermodynamic properties of graphene with changing temperature. [ABSTRACT FROM AUTHOR]

The contacts and fingers in the traditional high-voltage circuit breakers are all made of copper-tungsten alloy materials by powder metallurgy process at present, and their conductivity and hardness have reached the bottleneck, which cannot meet the demands of increasingly harsh working requirements. Graphene has good electrical conductivity, mechanical properties and high specific surface area. Doped into the traditional coppertungsten alloy, graphene is expected to greatly and simultaneously improve the electrical conductivity and hardness of copper-tungsten electric contacts. Tt has become the main development direction of current electrical contact materials research. Tn this paper, the research progress in strengthening methods of traditional copper-tungsten electric contact materials by using graphene and other reinforcing agents is systematically reviewed, and the strengthening mechanism of graphene on copper-tungsten electric contact materials is explored, so as to provide technical guidance for the development and application of new high strength and high conductivity graphene-reinforced copper-tungsten electric contact materials with new performance and long service life. [ABSTRACT FROM AUTHOR]

In this paper, graphene from inexpensive sucrose is prepared by in-situ growth directly on the Cu flakes, and Cu matrix materials(Cu-MMs) with various in-situ graphene content is fabricated by hot-press sintering. The effect of sucrose content on the phase composition, microstructure and thermal properties of bulk Cu-MMs is studied by XRD, SEM, thermal conductivity (TC) and coefficient of thermal expansion (CTE). Results obtained indicate that after the heat treatment at 800 ℃ for 15 min under the H2/Ar gas flow, the in-situ growth of graphene on the surface of Cu flakes occurs. The graphene exhibits good attachment to Cu matrix and homogenous dispersion, which is beneficial for thermal properties of Cu-MMs. With 0.73 vol% grapheme, the TC of Cu-MMs reaches 339 W/(m·K), which is higher by 19.3% than that of Cu, and meanwhile CTE is far lower than that of Cu from 50 ℃ to 300 ℃. [ABSTRACT FROM AUTHOR]

With the rapid development of the information age, a variety of electronic products have been widely used in our daily and working life. The electromagnetic pollution has become an increasingly serious problem. Absorbing materials with "thin, light, wide, strong" have been widely concerned. Tn this paper, BaF. 0押： graphene and Si()< are mixed by mechanical mixing method to prepare multi--absorbent composite powders. Using waterborne polyurethane as binder, polyamide fabric with multi-absorbent composite coating is prepared by tape casting. The structure, morphology, mechanical and wave absorption properties of the flexible composites are analyzed. The results show that when the absorber component is ().4(BaFei2 O1f)-Graphene)-().6Si()2 and the thickness of the absorbing coatings is 1.2 mm, the sample shows the best micro wave absorption performance with the minimum reflection loss of -14.58 dB, and the bandwidth with reflection loss below -1 0 dB of 0.94 GHz (1 2.91-1 3.58 GHz). Tt has the excellent performance of thin coating, high absorption intensity, wide absorption band and light weight. [ABSTRACT FROM AUTHOR]

Graphene (G)/graphene oxide (GO) has shown promising applications in improving the mechanics and functionality of cement materials with its excellent mechanical, electrical, and thermal conductivity properties. However, these nanomate rials are difficult to disperse in cement-based materials, which limits their practical application in cement-based composites. Tn recent years, researchers have begun to mix fibers with these nanomaterials into cement-based materials, and its dispersion performance has been greatly improved. Tn this paper, the influence of graphene, GO and other fiber mixture on cement-based composite materials is systematically described from five aspects of material dispersion in cement, cement hydration process, mechanical properties, functionality and durability, which has a guiding role in improving the performance of cement-based composite materials in the future. [ABSTRACT FROM AUTHOR]

Tn this paper, natural plant polyphenol-tannic acid (TA) is used as the reducing agent of graphene oxide (GO), and the green reduction and functionalization of GO are realized through the "one--step method0. Subsequently, the TA reduced graphene oxide (RGO) and single-walled carbon nanotubes (SWCNT) are combined to jointly construct a RGO/SWCNT conductive film with a three-dimensional structure. The transparent conductive film (TCF) has good electrical conductivity (when the light transmittance is 75.1 %, the surface resistance is 36.1 f2/sq), low roughness (the roughness of the film is only 5.45 nm), excellent flexibility (after 1 000 cycles of bending, the sheet resistance of the film remains unchanged) and good interfacial adhesion (the adhesion factor of the film is all 二》0.9). The composite film has good performance and can be applied in the field of flexible wearable devices. [ABSTRACT FROM AUTHOR]

Graphene is a nanomaterial composed of two-dimensional mono-crystalline structure with a single atomic layer. It has excellent properties in optics and mechanics, however its hydrophobicity and biological incompatibility limit its applications. In order to solve this problem, the functionalization of graphene has become a research hotspot in recent years. Functionalized graphene, including graphene oxide, graphene polymer composites, angular graphene, graphene, aerogels and super tough graphene, is modified by physicochemical treatment and structure improvement to make the graphene functional. Functionalized graphene has excellent photo- electric properties, including high sensitivity, high responsiveness and high detection degree, etc. It can be used for industrial detection and monitoring, three-dimensional morphology measurement, biomedicine and other neighborhood. In this paper, the properties and preparation methods of functionalized graphene are discussed, the latest progress of functionalized graphene is introduced, and its applications in different devices and its excellent properties are described. Meanwhile, the challenges faced by functional graphene are summarized and prospected. [ABSTRACT FROM AUTHOR]

With the rapid development of communication technology and electronic equipment, electromagnetic pollution has affected the normal operation of electronic equipment and the safety of human life. Therefore, the development of electromagnetic shielding materials is of great scientific significance. In recent years, polymer based carbon nanocomposites have developed rapidly in the field of electromagnetic shielding, showing many excellent properties, which have attracted wide attention in academic cireles. Based on our group's understanding and research in the field of electromagnetic shielding, this paper briefly introduces the principle of electromagnetic shielding and the preparation methods of polymer-based carbon nano composites, with emphasis on the research progress of polymer-based carbon nanocomposites prepared by backfilling method. finally, the future development trend and application of electromagnetic shielding materials are prospected. [ABSTRACT FROM AUTHOR]

Due to its unique two-dimensional lamella structure, graphene exhibits excellent electrical and mechanical properties, which has made it become a new hotspot in material research, bringing people a rich imagination. In this paper, based on the principle and technical characteristics as well as microstructure, various preparation techniques of graphene were compared. The microstructure characterization techniques and main properties of graphene were summarized. In view of the current bottleneck problem in graphene application, the modification methods of non-covalent and covalent bonds of graphene were described. The applications of graphene in batteries, energy storage, coating, medicine, sensors and additives, etc. were also reviewed. Finally, the future development direction of graphene was boldly predicted. [ABSTRACT FROM AUTHOR]

Graphene is considered to be an ideal reinforcement because of its excellent properties. It is also prone to agglomeration, which reduces the properties of materials. In this paper, K2FeO4 was transformed to Fe3O4 by graphite and anchored on the graphite sheet by high energy ball milling in order to increase the shear force of grinding ball on graphite and then strip graphene from graphite. Dispersed Fe-based/graphene nanocomposites were obtained by controlling milling time. The composite powders were characterized by SEM, XRD and infrared spectroscopy. The results show that the Fe-based/graphene nanocomposites achieved by ball milling for 2 hours exhibited the best dispersibility and the number of graphene lamellae was low. [ABSTRACT FROM AUTHOR]

Graphene has excellent material properties and a wide range of applications. The preparation technology of graphene-based materials has been highly valued. The key preparation techniques of graphene-based materials, such as surface functionalization, gamma ray irradiation, self-assembly, template synthesis, 3 D printing and powder metallurgy, were introduced in this paper. The technical principles of each process, preparation techniques and advantages and disadvantages of the resulting product were described. In order to better realize the application value of graphene-based materials, the next research was prospected. [ABSTRACT FROM AUTHOR]

Low thermal conductivity is a major disadvantage that limits the practical application of energy storage materials. Graphene with highly thermal conductivity can be used as a thermal conductive filler to effectively improve the thermal conductivity of energy storage materials. In this paper, the thermal conductivity and internal interaction of graphene/pentaerythritol (GE/PE) solid-solid phase change composites were simulated by reverse non-equilibrium molecular dynamics method and Materials Studio software with graphene (GE) mass fraction of 0.5%, 1 %, 1.5%, 2 %, 2.5% and 3%.The results show that the addition of graphene could effectively improve the thermal conductivity of pentaerythritol. With the increase of GE mass fraction, the thermal conductivity, interfacial thermal conductivity and interaction energy of GE/PE composite phase change material were gradually increased, and the trend amplitude was consistent. The overall increase in thermal conductivity was attributed t o the change of graphene structure. It could provide guidance for experimental research on graphene to improve thermal conductivity of pentaerythritol. [ABSTRACT FROM AUTHOR]

In this paper, a porous silicon powder material and a porous silicon/graphene composite material were prepared by using Al-20Si alloy as a raw material, and used as a negative electrode material for lithium ion batteries. A porous silicon powder material was prepared by etching an alloy with hydrochloric acid. Porous silicon/graphene composites were prepared by ultrasonically adding different amounts of graphene (0, 5%, 10%, 15%, 20%, 25%) to a silicon-based material, respectively. The experimental results show that the addition of 10% graphene to the porous silicon-based material had the best electrochemical performance. The first charge and discharge capacity was 2 552 mAh/g, and the charge and discharge capacity was finally stabilized at 540 mAh/g. The first charge and discharge efficiency was 78.5%. After the five cycles, the efficiency during subsequent charging and discharging was maintained at about 98%. When the amount of added graphene exceeded 10%, the performance gradually decreased as the amount of addition increased. The addition of graphene reduced the charge-discharge specific capacity but increased the cycling stability of the silicon. [ABSTRACT FROM AUTHOR]

In this paper, copper oxide nanorods (CuO-NRs) prepared by uniform precipitation method were combined with graphene (GNs) slurry, and CuO-NRs/GNs composite counter electrodes were prepared on FTO conductive glass substrated by electrohydrodynamics (EHD). The XRD phase analysis and SEM, TEM structure characterization indicated that the CuO-NRs/GNs composite film had a porous network structure. It proved that the CuO-NRs/GNs composite counter electrode had high electrocatalytic activity and faster electron transport rate through a series of electrochemical performance tests, and achieved photoelectric conversion efficiency of DSSC assembled by CuO-NRs/GNs composite counter electrodes (2.57%) reached the same level as that of Pt counter electrodes (3.46%). [ABSTRACT FROM AUTHOR]

With the development of electronics？ spaceflight and aviation, the integrated circuit develops rapidly, but it is often accompanied by the problem of heat dissipation ？ which affects the efficiency and the life of instruments. Considering the weight, corrosion resistance？ processing technology and cost？ polymer composites are the most promising materials for thermal conductivity. However, the inherent thermal conductivity of polymers is very low, so improving the thermal conductivity of polymers is very important for their applications in these fields ？ which has become a very important research topic in the past two decades. Tn this review paper, the following two aspects were mainly introduced. The micro thermal conductivity mechanism of polymers was analyzed and summarized from three aspects of molecular chain morphology ？ chain structure and inter-chain coupling. The main research progress in the thermal conductivity of graphene-filled polymer nanocomposites in recent years and the research challenges in the future were highlighted. [ABSTRACT FROM AUTHOR]

Tr ithis paper, the growth of graphene on sapphire substrate was studied by the experimental preparation and simulation using chemical vapor deposition (CVD) method 􀀀 which focused on the effect of substrate surface morphology and growth temperature. The microstructure of graphene was investigated by atomic force microscope (AFM),X-ray diffraction (XRD) ？ field emission scanning electron microscope (FESEM) ？ Raman spectroscopy (Raman),and high resolution transmission electron microscope (HRTEM) respectively. The simulation results indicated that hydrogen had an important influence on the surface morphology of the substrate. Under the action of H atom ? the Al-() bond was elongated by 51.42% ? which was almost fractured ？ and it affected the surface roughness of the sapphire substrate. Tt was found that H had an etching effect on the surface of sapphire substrate？ and the surface roughness Ra of the etched sapphire substrate became larger, which made it difficult to grow graphene. When the growth temperature increased 􀀀 the quality of the graphene also became better. [ABSTRACT FROM AUTHOR]

In this paper, graphene was synthesized on sapphire substrate by chemical vapor deposition (CVD) method, and the effect of growth time on hydrophobic properties and microstructure of graphene was investigated. Contact-angle meter, Fourier transform infrared spectrometer, Raman spectrometer and field emission scanning electron microscopy were applied to study hydrophobic and microscopic structure of graphene, respectively. It shows that after growing 30 min, maximum contact angle of graphene is 129.96°, it presents hydrophobic properties. Meantime, infrared test shows only carbon-carbon double bonds. Raman analysis also indicates three characteristic peaks of graphene after growing 10-30 min. larger contact angle makes graphene as a potential hydrophobic material, and it can even be a promising superhydrophobic material by its hydrophobic modification. [ABSTRACT FROM AUTHOR]

Graphene and carbon nanotubes are new carbon nano-materials, which have the characteristics of great specific surface area, good electrical conductivity and excellent mechanical properties. In this paper graphene/carbon nanotubes composite materials were prepared by using microwave puffing method. Carbon nanotubes not only played a role in connecting the graphene layer structure, but also acted as a synergistic co graphene absorbing effect. Meanwhile the catalyst of carbon nanotubes under microwave condition was decomposed into nano magnetic particles, improving the absorbing properties of the composite material. The morphology and chemical composition of the carbon nanocomposites were examined by SEM, EDX and TEM, respectively. The complex relative permittivity and permeability of the absorber were measured by using a microwave network analyzer in the frequency range of 2-18 GHz. The reflection loss curves of the carbon nanocomposites were calculated using computer simulation technique. The results showed that the electromagnetic loss mechanism consists of dielectric loss and magnetic loss. It was found that in the frequency range of 2-18 GHz, with the increase of the matching thickness, the maximum absorbing peaks of the carbon nanocomposites shifted to lower frequency region. When the matching thickness was 2.5 mm, the maximum absorption peak of the carbon nanocomposites was -28 dB at 14.4 GHz and the maximum reflection loss of 10 dB was achieved within the range of 12.417.7 GHz. [ABSTRACT FROM AUTHOR]

Supercapacitors are novel energy storage elements between traditional capacitors and chemical batteries. In general, supercapacitors possess high power density, fast charge-discharge speed, long working life and low environmental pollution. As a significant component, electrode materials make an important effect on the electrochemical performance and commercial applications on the supercapacitors. In recent years, the novel carbon materials, such as carbon aerogel, carbon nanotubes, carbon fibers and graphene, have been a research hotspot, which can be promising candidate for the new generation electrode materials. In this paper, the recent advancement and development of the novel carbon materials were reviewed. Moreover, the urgent requirement and the challenges of the carbon materials were proposed as well as the perspective in future, which offered theoretical basis and technique support for the construction of energy internet. [ABSTRACT FROM AUTHOR]