Graphene Nanoplatelets

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 8976 Experts worldwide ranked by ideXlab platform

Alejandro Ureña - One of the best experts on this subject based on the ideXlab platform.

  • Tribological Properties of Different Types of Graphene Nanoplatelets as Additives for the Epoxy Resin
    Applied Sciences, 2020
    Co-Authors: Mónica Campo, Alberto Jiménez-suárez, Alejandro Ureña
    Abstract:

    The use of Graphene Nanoplatelets for several purposes such as barrier properties and structural health monitoring is widely studied in polymer-based coating technology. Nevertheless, their extremely good effect on wear resistance makes them particularly interesting for coating technology. The effect of Graphene Nanoplatelets addition on the wear behaviour of an epoxy resin was analysed. The effects of Graphene Nanoplatelets content (0–8 wt.%), morphology and functionalization in wear behaviour were analysed by evaluating the main wear parameters of the nanocomposites studied. The morphology of the wear surfaces was analysed by scanning electron microscopy (SEM) and 3D optical profilometry in order to evaluate the mechanism and severity of wear. The results showed that the wear behaviour of the epoxy resin improved considerably with the addition of Graphene, especially for higher contents. Moreover, as the wear mechanism depends on the morphology of Graphene Nanoplatelets, it was concluded that the proper selection of Graphene can be made depending on the chosen application.

  • Influence of Graphene Nanoplatelets on curing kinetics and rheological properties of a benzoxazine resin
    Materials Today Communications, 2020
    Co-Authors: V. García-martínez, M. R.gude, S. Calvo, M.r. Martínez-miranda, Alejandro Ureña
    Abstract:

    Abstract The effect of two types of Graphene Nanoplatelets on the curing kinetics, gelation and vitrification behaviour of a benzoxazine resin was investigated by means of differential scanning calorimetry and rheological experiments. The results showed that the incorporation of Graphene Nanoplatelets did not change the autocatalytic nature of curing reaction. However, when benzoxazine was doped with the nanofiller supplied by XG-Sciences an acceleration effect in curing reaction was observed, especially when a 2 wt.% was added. This catalytic effect was demonstrated by the reduction of peak temperature, apparent activation energy and the shorter gelation and vitrification times. Finally, the curing kinetic equation for benzoxazine and its nanocomposites was obtained by linear model-fitting of non-isothermal experiments and it matched reasonably well with the experimental results from both non-isothermal and isothermal tests.

  • Influence of Thickness and Lateral Size of Graphene Nanoplatelets on Water Uptake in Epoxy/Graphene Nanocomposites
    Applied Sciences, 2018
    Co-Authors: Silvia G. Prolongo, R. Moriche, Alberto Jiménez-suárez, Alejandro Ureña
    Abstract:

    In this study, the hydrothermal resistance of an epoxy resin (aircraft quality) reinforced with Graphene is analyzed. Different geometries and aspect ratios (thickness and lateral dimensions) of Graphene Nanoplatelets were studied. The addition of these Graphene Nanoplatelets induces important advantages, such as an increase of the glass transition temperature and stiffness and an enhancement of barrier properties of the epoxy matrix, in spite of the excellent behavior of pristine resin. The effectiveness of Graphene Nanoplatelets increases with their specific surface area while their dispersion degree is suitable. Thinner Nanoplatelets tend to wrinkle, decreasing their efficiency as nanofillers. Graphene used as reinforcement not only reduces the absorbed moisture content but also decreases its effect on the thermal and mechanical properties related to the matrix.

  • Strain Sensing Based on Multiscale Composite Materials Reinforced with Graphene Nanoplatelets.
    Journal of Visualized Experiments, 2016
    Co-Authors: R. Moriche, M. Campo, Alberto Jiménez-suárez, Silvia G. Prolongo, Maria Sanchez, Alejandro Ureña
    Abstract:

    The electrical response of NH2-functionalized Graphene Nanoplatelets composite materials under strain was studied. Two different manufacturing methods are proposed to create the electrical network in this work: (a) the incorporation of the Nanoplatelets into the epoxy matrix and (b) the coating of the glass fabric with a sizing filled with the same Nanoplatelets. Both types of multiscale composite materials, with an in-plane electrical conductivity of ~10-3 S/m, showed an exponential growth of the electrical resistance as the strain increases due to distancing between adjacent functionalized Graphene Nanoplatelets and contact loss between overlying ones. The sensitivity of the materials analyzed during this research, using the described procedures, has been shown to be higher than commercially available strain gauges. The proposed procedures for self-sensing of the structural composite material would facilitate the structural health monitoring of components in difficult to access emplacements such as offshore wind power farms. Although the sensitivity of the multiscale composite materials was considerably higher than the sensitivity of metallic foils used as strain gauges, the value reached with NH2 functionalized Graphene Nanoplatelets coated fabrics was nearly an order of magnitude superior. This result elucidated their potential to be used as smart fabrics to monitor human movements such as bending of fingers or knees. By using the proposed method, the smart fabric could immediately detect the bending and recover instantly. This fact permits precise monitoring of the time of bending as well as the degree of bending.

  • Graphene Nanoplatelets thickness and lateral size influence on the morphology and behavior of epoxy composites
    European Polymer Journal, 2014
    Co-Authors: Silvia G. Prolongo, R. Moriche, Alberto Jiménez-suárez, Alejandro Ureña
    Abstract:

    Abstract Graphene Nanoplatelets/epoxy nanocomposites were prepared using a high shear toroidal mixer as dispersion technique. Suitable dispersions were obtained. Several Graphene Nanoplatelets, with different thickness and lateral dimensions, were added in order to analyze the influence of these parameters in the final properties. An important nanofiller concentration gradient was found from the top to the bottom in nanocomposites reinforced with large Nanoplatelets due to a natural deposition by gravity. This phenomenon is not appreciable when the Nanoplatelets size decreased. However, the small Nanoplatelets have a greater tendency to agglomerate in packages of several parallel particles. In general, Graphene Nanoplatelets addition caused an increment in glass transition temperature, stiffness and thermal stability compared to the epoxy resin. However, it was also found that Graphene Nanoplatelets dimensions significantly affect to these enhancements. Nanocomposites reinforced with larger and thicker Nanoplatelets presented lower glass transition temperature, higher modulus and higher decomposition temperature.

B T T Chu - One of the best experts on this subject based on the ideXlab platform.

  • mechanical reinforcement and thermal conductivity in expanded Graphene Nanoplatelets reinforced epoxy composites
    Chemical Physics Letters, 2012
    Co-Authors: Sanjukta Chatterjee, J W Wang, W S Kuo, Nyanhwa Tai, Christoph G Salzmann, Rebecca Hollertz, Frank Nuesch, B T T Chu
    Abstract:

    Abstract Influence of reinforcements on mechanical and thermal properties of Graphene Nanoplatelets/epoxy composites is investigated. Amine functionalized expanded Graphene Nanoplatelets (EGNPs) were dispersed within epoxy resins using high-pressure processor followed by three roll milling. Functionality on the EGNPs was confirmed with FTIR and micro-Raman spectroscopy. Bending and nano-mechanical testing was performed on the composites. Incorporation of EGNPs improved the flexural modulus and hardness of the composite and increased fracture toughness by up to 60%. Marked improvement was observed in thermal conductivity of the composites reaching 36% at 2 wt.% loading. Functionalized EGNPs exhibited significant improvements indicating favorable interaction at EGNPs/polymer interface.

  • comparing carbon nanotubes and Graphene Nanoplatelets as reinforcements in polyamide 12 composites
    Nanotechnology, 2011
    Co-Authors: Sanjukta Chatterjee, Frank Nuesch, B T T Chu
    Abstract:

    We investigate the influence of nanofillers including carbon nanotubes (CNTs) and Graphene Nanoplatelets on a thermoplastic engineering polymer, polyamide 12 (PA12). The comparison between these two important nanofillers as to how they influence the structure and properties of the polymer is systematically studied. The polymer–nanofiller composites were prepared using a twin-screw micro-extruder and the composite was thereafter hot pressed into thin films. The structure (using wide angle x-ray diffraction and differential scanning calorimetry) and properties (through tensile testing and conductivity measurement) of the thin films have been investigated. The composites incorporating surfactant showed the best CNT distribution and dispersion, causing an improvement of up to 80% in the toughness modulus over pure PA12. Electrical percolation could also be achieved at nanofiller concentrations of 1 to 2 wt%. In this study we observed that CNT fillers bring about more pronounced improvements in PA12 compared to Graphene Nanoplatelets, as far as mechanical and electrical properties are concerned.

Savi Patrizia - One of the best experts on this subject based on the ideXlab platform.

  • Microstrip Tunable Antenna Based on Commercial Graphene Nanoplatelets
    IEEE, 2020
    Co-Authors: Yasir M., Savi Patrizia
    Abstract:

    This paper presents a tunable antenna with frequency reconfigurability caused by an external bias voltage. The antenna is composed of a patch with two stubs and commercial Graphene Nanoplatelets deposited in designated gaps between the antenna and the stubs. As the Graphene Nanoplatelets are biased with a dc voltage, their sheet resistance is varied causing a change in the reactance at the radiating edge of the patch antenna resulting in a variation of the resonant frequency. Even though commercial Graphene Nanoplatelets bearing higher sheet resistance are deployed yet the prototype is designed to provide comparable frequency shift to tunable antennas based on lab grown Graphene flakes. Simulated values of return loss are compared to measured values. The resulting shift in the frequency is 370MHz at a frequency of 5GHz

  • Dynamically tunable phase shifter with commercial Graphene Nanoplatelets
    'MDPI AG', 2020
    Co-Authors: Yasir M., Savi Patrizia
    Abstract:

    In the microwave frequency band the conductivity of Graphene can be varied to design a number of tunable components. A tunable phase shifter based on commercial Graphene Nanoplatelets is introduced. The proposed configuration consists of a microstrip line with two stubs connected with a taper. On each side of the stubs there is a gap, short circuited through a via, where the commercial Graphene Nanoplatelets are drop casted. By applying a DC bias voltage that alters the Graphene resistance the phase of the transmitted signal through the microstrip line can be varied. In order to maximize the phase shift of the transmitted signal and minimize the insertion loss, the length of the taper and the stubs are optimized by the help of circuit model and full-wave simulations. A prototype working at 4GHz is fabricated and measured. A phase variation of 33 degrees is acquired with an amplitude variation of less than 0.4dB

Sanjukta Chatterjee - One of the best experts on this subject based on the ideXlab platform.

  • mechanical reinforcement and thermal conductivity in expanded Graphene Nanoplatelets reinforced epoxy composites
    Chemical Physics Letters, 2012
    Co-Authors: Sanjukta Chatterjee, J W Wang, W S Kuo, Nyanhwa Tai, Christoph G Salzmann, Rebecca Hollertz, Frank Nuesch, B T T Chu
    Abstract:

    Abstract Influence of reinforcements on mechanical and thermal properties of Graphene Nanoplatelets/epoxy composites is investigated. Amine functionalized expanded Graphene Nanoplatelets (EGNPs) were dispersed within epoxy resins using high-pressure processor followed by three roll milling. Functionality on the EGNPs was confirmed with FTIR and micro-Raman spectroscopy. Bending and nano-mechanical testing was performed on the composites. Incorporation of EGNPs improved the flexural modulus and hardness of the composite and increased fracture toughness by up to 60%. Marked improvement was observed in thermal conductivity of the composites reaching 36% at 2 wt.% loading. Functionalized EGNPs exhibited significant improvements indicating favorable interaction at EGNPs/polymer interface.

  • comparing carbon nanotubes and Graphene Nanoplatelets as reinforcements in polyamide 12 composites
    Nanotechnology, 2011
    Co-Authors: Sanjukta Chatterjee, Frank Nuesch, B T T Chu
    Abstract:

    We investigate the influence of nanofillers including carbon nanotubes (CNTs) and Graphene Nanoplatelets on a thermoplastic engineering polymer, polyamide 12 (PA12). The comparison between these two important nanofillers as to how they influence the structure and properties of the polymer is systematically studied. The polymer–nanofiller composites were prepared using a twin-screw micro-extruder and the composite was thereafter hot pressed into thin films. The structure (using wide angle x-ray diffraction and differential scanning calorimetry) and properties (through tensile testing and conductivity measurement) of the thin films have been investigated. The composites incorporating surfactant showed the best CNT distribution and dispersion, causing an improvement of up to 80% in the toughness modulus over pure PA12. Electrical percolation could also be achieved at nanofiller concentrations of 1 to 2 wt%. In this study we observed that CNT fillers bring about more pronounced improvements in PA12 compared to Graphene Nanoplatelets, as far as mechanical and electrical properties are concerned.

Hamed Safarpour - One of the best experts on this subject based on the ideXlab platform.

Related terms

Graphene Nanoplatelets - 15 days free trial to Access Experts & Abstracts