Journal articles: 'Graphyne networks'

1

Yang, Yu Lin, Zhe Yong Fan, Ning Wei, and Yong Ping Zheng. "Mechanical Properties of Hydrogen Functionalized Graphyne - A Molecular Dynamics Investigation." Advanced Materials Research 472-475 (February 2012): 1813–17. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.1813.

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In this paper the mechanical properties of a series of hydrogen functionalized graphyne are investigated through acting tensile loads on the monolayer networks. Molecular dynamics simulations are performed to calculate the fracture strains and corresponding maximum forces for pristine graphyne along both armchair and zigzag directions. Furthermore, hydrogen functionalized graphynes with different functionalization sites are analyzed to investigate the effect of functionlization on the mechanical performance. Finally, Young's modulus of all the investigated architectures are computed. The obtained results show that monolayer graphyne is mechanically stable with high strength and stiffness, and the mechanical performance can be tuned through structure engineering and functionalization.

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Haley, Michael M. "Synthesis and properties of annulenic subunits of graphyne and graphdiyne nanoarchitectures." Pure and Applied Chemistry 80, no. 3 (January 1, 2008): 519–32. http://dx.doi.org/10.1351/pac200880030519.

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This report describes the synthetic strategies toward and optoelectronic properties of substructures of the non-natural, planar carbon networks graphyne and graphdiyne, which are based on the dehydrobenzo[12]annulene and dehydrobenzo[18]annulene framework, respectively.

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Chandra Shekar, Sarap, and Rotti Srinivasamurthy Swathi. "Molecular switching on graphyne and graphdiyne: Realizing functional carbon networks in synergy with graphene." Carbon 126 (January 2018): 489–99. http://dx.doi.org/10.1016/j.carbon.2017.10.049.

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Degabriele, Edera P., James N. Grima-Cornish, Daphne Attard, Roberto Caruana-Gauci, Ruben Gatt, Kenneth E. Evans, and Joseph N. Grima. "On the Mechanical Properties of Graphyne, Graphdiyne, and Other Poly(Phenylacetylene) Networks." physica status solidi (b) 254, no. 12 (November 27, 2017): 1700380. http://dx.doi.org/10.1002/pssb.201700380.

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Kehoe, Joshua M., James H. Kiley, Jamieson J. English, Charles A. Johnson, Ryan C. Petersen, and Michael M. Haley. "Carbon Networks Based on Dehydrobenzoannulenes. 3. Synthesis of Graphyne Substructures1." Organic Letters 2, no. 7 (April 2000): 969–72. http://dx.doi.org/10.1021/ol005623w.

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Yang, Zechao, Lukas Fromm, Tim Sander, Julian Gebhardt, Tobias A. Schaub, Andreas Görling, Milan Kivala, and Sabine Maier. "On‐Surface Assembly of Hydrogen‐ and Halogen‐Bonded Supramolecular Graphyne‐Like Networks." Angewandte Chemie 132, no. 24 (April 2020): 9636–42. http://dx.doi.org/10.1002/ange.201916708.

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Yang, Zechao, Lukas Fromm, Tim Sander, Julian Gebhardt, Tobias A. Schaub, Andreas Görling, Milan Kivala, and Sabine Maier. "On‐Surface Assembly of Hydrogen‐ and Halogen‐Bonded Supramolecular Graphyne‐Like Networks." Angewandte Chemie International Edition 59, no. 24 (April 2020): 9549–55. http://dx.doi.org/10.1002/anie.201916708.

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8

Kehoe, Joshua M., James H. Kiley, Jamieson J. English, Charles A. Johnson, Ryan C. Petersen, and Michael M. Haley. "ChemInform Abstract: Carbon Networks Based on Dehydrobenzoannulenes. Part 3. Synthesis of Graphyne Substructures." ChemInform 31, no. 27 (June 7, 2010): no. http://dx.doi.org/10.1002/chin.200027097.

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9

Johnson, Charles A., Yunyi Lu, and Michael M. Haley. "Carbon Networks Based on Benzocyclynes. 6. Synthesis of Graphyne Substructures via Directed Alkyne Metathesis§." Organic Letters 9, no. 19 (September 2007): 3725–28. http://dx.doi.org/10.1021/ol7014253.

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10

Yang, Zechao, Tim Sander, Julian Gebhardt, Tobias A. Schaub, Jörg Schönamsgruber, Himadri R. Soni, Andreas Görling, Milan Kivala, and Sabine Maier. "Metalated Graphyne-Based Networks as Two-Dimensional Materials: Crystallization, Topological Defects, Delocalized Electronic States, and Site-Specific Doping." ACS Nano 14, no. 12 (November 25, 2020): 16887–96. http://dx.doi.org/10.1021/acsnano.0c05865.

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Czajka, Michael, Robert A. Shanks, and Ing Kong. "Preparation of graphene and inclusion in composites with poly(styrene-b-butadiene-b-styrene)." Science and Engineering of Composite Materials 22, no. 1 (January 1, 2015): 7–16. http://dx.doi.org/10.1515/secm-2013-0119.

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AbstractThe aim of this work was to prepare and characterize nanocomposites containing graphene from intercalated graphite. The graphene was produced by rapid thermal expansion using expandable graphite oxide or obtained commercially. The polymer used was poly(styrene-b-butadiene-b-styrene) (SBS). The SBS was dissolved in p-xylene and the graphene was ultrasonically suspended in the xylene solution. The morphology, dynamic mechanical, electrical, and thermal properties of composites were characterized. Graphene at 1% (w/w) (hydrogen atmosphere) was found to increase the storage modulus (68%) and loss modulus (147%) of the glassy state of polybutadiene in SBS. The damping factor of SBS was enhanced by 74% corresponding to the polystyrene phase of SBS using Cheap Tubes graphene. The composites were insulators at 1% (w/w). The styrene groups in SBS strongly adsorb onto the graphenes, preventing a percolation network that would enhance electrical permittivity. Graphene enhanced physical crosslinks of the polystyrene phase to increase the modulus at low concentration. Graphene dispersion using ultrasonic shear depended on π-π interactions between the aromatic rings of the solvent, graphene, and polystyrene. This is a simple, fast, cheap, and scalable way of making high-quality graphene and a new way of graphene dispersal in polymers.

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Wang, Ziming, Yiyang Cao, Decai Pan, and Sen Hu. "Vertically Aligned and Interconnected Graphite and Graphene Oxide Networks Leading to Enhanced Thermal Conductivity of Polymer Composites." Polymers 12, no. 5 (May 14, 2020): 1121. http://dx.doi.org/10.3390/polym12051121.

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Natural graphite flakes possess high theoretical thermal conductivity and can notably enhance the thermal conductive property of polymeric composites. Currently, because of weak interaction between graphite flakes, it is hard to construct a three-dimensional graphite network to achieve efficient heat transfer channels. In this study, vertically aligned and interconnected graphite skeletons were prepared with graphene oxide serving as bridge and support via freeze-casting method. Three freezing temperatures were utilized, and the resulting graphite and graphene oxide network was filled in a polymeric matrix. Benefiting from the ultralow freezing temperature of −196 °C, the network and its composite occupied a more uniform and denser structure, which lead to enhanced thermal conductivity (2.15 W m−1 K−1) with high enhancement efficiency and prominent mechanical properties. It can be significantly attributed to the well oriented graphite and graphene oxide bridges between graphite flakes. This simple and effective strategy may bring opportunities to develop high-performance thermal interface materials with great potential.

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Suh, JY, SE Shin, and DH Bae. "Electrical properties of polytetrafluoroethylene/few-layer graphene composites fabricated by solid-state processing." Journal of Composite Materials 51, no. 18 (October 13, 2016): 2565–73. http://dx.doi.org/10.1177/0021998316674349.

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High electrical performances of polytetrafluoroethylene composites containing few-layer graphenes are established by solid-state processing. Polytetrafluoroethylene and FLG powders are mechanically mixed without solvents at room temperature, and hot-pressed. Few-layer graphenes are attached to the polytetrafluoroethylene powder, and gradually wrap the powder surface during milling with a low milling speed. The few-layer graphene-wrapped polytetrafluoroethylene powders readily facilitate the formation of a continuous few-layer graphene network due to the contact between adjacent few-layer graphene-wrapped powders. The final composites using few-layer graphene-wrapped polytetrafluoroethylene powders include a three-dimensional conducting network. Eventually, the wrapping morphology of the polytetrafluoroethylene/few-layer graphene powder results in a remarkable electrical conductivity of 7353 Sm−1 at 30 vol. %. few-layer graphene loading.

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Tarannum, Fatema, Swapneel S. Danayat, Avinash Nayal, Rajmohan Muthaiah, Roshan Sameer Annam, and Jivtesh Garg. "Large Enhancement in Thermal Conductivity of Solvent−Cast Expanded Graphite/Polyetherimide Composites." Nanomaterials 12, no. 11 (May 30, 2022): 1877. http://dx.doi.org/10.3390/nano12111877.

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We demonstrate in this work that expanded graphite (EG) can lead to a very large enhancement in thermal conductivity of polyetherimide−graphene and epoxy−graphene nanocomposites prepared via solvent casting technique. A k value of 6.6 W⋅m−1⋅K−1 is achieved for 10 wt% composition sample, representing an enhancement of ~2770% over pristine polyetherimide (k~0.23 W⋅m−1⋅K−1). This extraordinary enhancement in thermal conductivity is shown to be due to a network of continuous graphene sheets over long−length scales, resulting in low thermal contact resistance at bends/turns due to the graphene sheets being covalently bonded at such junctions. Solvent casting offers the advantage of preserving the porous structure of expanded graphite in the composite, resulting in the above highly thermally conductive interpenetrating network of graphene and polymer. Solvent casting also does not break down the expanded graphite particles due to minimal forces involved, allowing for efficient heat transfer over long−length scales, further enhancing overall composite thermal conductivity. Comparisons with a recently introduced effective medium model show a very high value of predicted particle–particle interfacial conductance, providing evidence for efficient interfacial thermal transport in expanded graphite composites. Field emission environmental scanning electron microscopy (FE−ESEM) is used to provide a detailed understanding of the interpenetrating graphene−polymer structure in the expanded graphite composite. These results open up novel avenues for achieving high thermal conductivity polymer composites.

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15

Polyakova, Polina V., and Julia A. Baimova. "Mechanical Properties of Graphene Networks under Compression: A Molecular Dynamics Simulation." International Journal of Molecular Sciences 24, no. 7 (April 3, 2023): 6691. http://dx.doi.org/10.3390/ijms24076691.

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Molecular dynamics simulation is used to study and compare the mechanical properties obtained from compression and tension numerical tests of multilayered graphene with an increased interlayer distance. The multilayer graphene with an interlayer distance two-times larger than in graphite is studied first under biaxial compression and then under uniaxial tension along three different axes. The mechanical properties, e.g., the tensile strength and ductility as well as the deformation characteristics due to graphene layer stacking, are studied. The results show that the mechanical properties along different directions are significantly distinguished. Two competitive mechanisms are found both for the compression and tension of multilayer graphene—the crumpling of graphene layers increases the stresses, while the sliding of graphene layers through the surface-to-surface connection lowers it. Multilayer graphene after biaxial compression can sustain high tensile stresses combined with high plasticity. The main outcome of the study of such complex architecture is an important step towards the design of advanced carbon nanomaterials with improved mechanical properties.

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El-Refaey, Ahmed, Yoshihiro Ito, and Masuki Kawamoto. "Nanocomposite Hydrogels Containing Few-Layer Graphene Sheets Prepared through Noncovalent Exfoliation Show Improved Mechanical Properties." Nanomaterials 12, no. 18 (September 9, 2022): 3129. http://dx.doi.org/10.3390/nano12183129.

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Hydrogels show great potential as soft materials for biomedical applications and flexible devices. However, conventional hydrogels exhibit poor mechanical strengths owing to the presence of water in their polymer networks. Therefore, improving the mechanical properties of hydrogels by controlling the chemical and physical structures that affect their macroscopic behaviors is a challenging issue. In this study, we developed a nanocomposite (NC) hydrogel that harbors exfoliated few-layer graphene sheets through noncovalent interactions. The bifunctional polymer PImQ, which contains both aromatic and cationic groups, was found to enable the direct exfoliation of graphite to few-layer graphene through π–π interactions in 2.7% yield. The poly(acrylamide)-based NC hydrogel containing the PImQ/graphene composite as a nanofiller shows a 3.4-fold increase in tensile stress compared with the hydrogel without the nanofiller. The introduction of the PImQ/graphene nanocomposite also increases the fracture stress of the NC hydrogel through cation–π and π–π interactions. The improved mechanical properties of the NC hydrogel result from the synergistic effects of the chemical crosslinking of the polymer network and the physical crosslinking of the polymer/graphene nanofiller.

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Levchenko, Igor, Jinghua Fang, Kostya (Ken) Ostrikov, Ludovico Lorello, and Michael Keidar. "Morphological Characterization of Graphene Flake Networks Using Minkowski Functionals." Graphene 05, no. 01 (2016): 25–34. http://dx.doi.org/10.4236/graphene.2016.51003.

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P, Kavya, Soorya V. S, and Binitha N. Narayanan. "Ball-Mill Assisted Green One-Pot Synthesis of ZnO/Graphene Nanocomposite for Selective Electrochemical Sensing of aquatic pollutant 4-nitrophenol." Teknomekanik 4, no. 2 (October 20, 2021): 64–71. http://dx.doi.org/10.24036/teknomekanik.v4i2.10872.

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ZnO, having good transparency, high electron mobility and lower electrical noise, is an excellent material for electrochemical studies. Due to its high surface area and electrical conductivity, graphene is well suitable for the good dispersion of metal oxides for electronic/electrochemical applications. Graphene prevents particle agglomeration, whereas the addition of metal oxide prevents layer restacking in graphene. The bulk preparation of graphene via cost-effective and green methods are preferred. The aromatic conjugated π-network along the whole surface is not attained in large scale graphite oxide assisted production due to the defects and functional groups introduced during the hazardous synthetic procedure. Here, less defective graphene is synthesised via ball milling of graphite using metal oxalate as an exfoliating agent for the first time. Calcination of metal oxalate inserted graphite leads to the enormous evolution of gases thereby sliding the graphitic layers, leading to the formation of graphene sheets decorated with ZnO spherical nanoparticles’ bunches. The layer exfoliation and metal oxide incorporation are achieved here via a one-pot synthesis strategy. The use of ZnO/graphene in the selective sensing of 4-nitrophenol is investigated using cyclic voltammetric measurements in the presence of interfering compounds such as glucose, uric acid, ascorbic acid and H2O2.

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LI, HAI, and CHUNXIANG LU. "PREPARATION OF THREE-DIMENSIONAL GRAPHENE NETWORKS FOR USE AS ANODE OF LITHIUM ION BATTERIES." Functional Materials Letters 06, no. 06 (November 27, 2013): 1350063. http://dx.doi.org/10.1142/s179360471350063x.

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The three-dimensional (3D) graphene networks have been prepared by annealing the mixture of graphene oxide and SiO 2 nanoparticles and then etching SiO 2. The obtained material was characterized by X-ray diffraction, scanning electron microscope and transmission electron microscopy, which revealed that 3D networks consisting of crumpled graphene nanosheets were preserved after the removal of SiO 2. When used as anode material of lithium ion batteries, the graphene networks showed a reversible capacity of 610.9 mAh/g at a current density of 50 mA/g after 50 cycles and excellent rate capability of 291.5 mAh/g at a current density of 5000 mA/g. The good electrochemical performance can be attributed to the network structure, which enables graphene to electrochemically absorb more lithium ions and significantly improve the electrical conductivity of electrode. The graphene networks have the potential applications in ultracapacitor and catalyst supports.

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Edward, Kaamil, Kabir Mamun, Sumesh Narayan, Mansour Assaf, David Rohindra, and Upaka Rathnayake. "State-of-the-Art Graphene Synthesis Methods and Environmental Concerns." Applied and Environmental Soil Science 2023 (February 2, 2023): 1–23. http://dx.doi.org/10.1155/2023/8475504.

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Graphene, a 2D sp2 hybridized carbon sheet consisting of a honeycomb network, is the building block of graphite. Since its discovery in 2004, graphene’s exceptional electronic and mechanical properties have peaked interest in various applications. However, the inability to mass produce high-quality graphene affordably currently limits the practical application of the material. Researchers are continuously working on advancing graphene synthesis methods to alleviate these limitations. Therefore, this review looks at the overview of established graphene synthesis methods and characterization techniques, and then highlights an in-depth review of graphene production through flash joule heating. The environmental concerns related to graphene synthesis are also presented in this review paper.

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Zhuang, Yuan, Yan Kong, Kun Han, Haotian Hao, and Baoyou Shi. "A physically cross-linked self-healable double-network polymer hydrogel as a framework for nanomaterial." New Journal of Chemistry 41, no. 24 (2017): 15127–35. http://dx.doi.org/10.1039/c7nj03392c.

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Yin, Yanchao, Guoliang Zhang, Xianmang Xu, Peiyu Zhao, and Liran Ma. "Intermolecular hydrogen bond ruptured by graphite with different lamellar number." Royal Society Open Science 8, no. 9 (September 2021): 210565. http://dx.doi.org/10.1098/rsos.210565.

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Intermolecular hydrogen bonds are formed through the electrostatic attraction between the hydrogen nucleus on a strong polar bond and high electronegative atom with an unshared pair of electrons and a partial negative charge. It affects the physical and chemical properties of substances. Based on this, we presented a physical method to modulate intermolecular hydrogen bonds for not changing the physical–chemical properties of materials. The graphite and graphene are added into the glycerol, respectively, by being used as a viscosity reducer in this paper. The samples are characterized by Raman and 1H-nuclear magnetic resonance. Results show that intermolecular hydrogen bonds are adjusted by graphite or graphene. The rheology of glycerol is reduced to varying degrees. Transmission electron microscopes and computer simulation show that the spatial limiting action of graphite or graphene is the main cause of breaking the intermolecular hydrogen bond network structure. We hope this work reveals the potential interplay between nanomaterials and hydroxyl liquids, which will contribute to the field of solid–liquid coupling lubrication.

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Pawar, Pranav Bhagwan, Santosh K. Maurya, Ragvendra Pratap Chaudhary, Dhanashree Badhe, Sumit Saxena, and Shobha Shukla. "Water Purification using Graphene Covered Micro-porous, Reusable Carbon Membrane." MRS Advances 1, no. 20 (2016): 1411–16. http://dx.doi.org/10.1557/adv.2016.199.

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ABSTRACTThe discovery of graphene based materials has led to significant advancement in several different areas. The large surface area, nanoporous structure and availability of delocalized electron network provide a unique opportunity for purification of solvents via adsorption, absorption or simple trapping. This makes graphene based materials as potential candidates for purification and desalination of water. Here we report synthesis of 3D porous network of oxidized graphene for purification of sea water. The membranes fabricated using these frameworks are hierarchically linked intrinsically defected oxidised graphene sheets by long micro-channels and capable of filtering small ions such as Na+ and Cl-. These are easy to fabricate, reusable and economically viable especially for point of use application. We finally show a fabricated device using membrane made from these 3D networks of oxidized graphene.

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Liu, Yuanjun, Qianqian Lu, Jing Wang, and Xiaoming Zhao. "A Flexible Sandwich Structure Carbon Fiber Cloth with Resin Coating Composite Improves Electromagnetic Wave Absorption Performance at Low Frequency." Polymers 14, no. 2 (January 7, 2022): 233. http://dx.doi.org/10.3390/polym14020233.

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In order to improve the electromagnetic wave absorbing performance of carbon fiber cloth at low frequency and reduce the secondary pollution caused by the shielding mechanism, a flexible sandwich composite was designed by a physical mixing coating process. This was composed of a graphene layer that absorbed waves, a carbon fiber cloth layer that reflected waves, and a graphite layer that absorbed transmitted waves. The influence of the content of graphene was studied by a control variable method on the electromatic and mechanical properties. The structures of defect polarization relaxation and dipole polarization relaxation of graphene, the interfacial polarization and electron polarization of graphite, the conductive network formed in the carbon fiber cloth, and the interfacial polarization of each part, combined together to improve the impedance matching and wave multiple reflections of the material. The study found that the sample with 40% graphene had the most outstanding absorbing performance. The minimum reflection loss value was −18.62 dB, while the frequency was 2.15 GHz and the minimum reflection loss value compared to the sample with no graphene increased 76%. The composites can be mainly applied in the field of flexible electromagnetic protection, such as the preparation of stealth tent, protective covers of electronic boxes, helmet materials for high-speed train drivers, etc.

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Rahayu, Endah Fitriani, Bunnari Bunnari, and Andri Hardyansyah. "Reduction of Graphene Oxide: Controlled Synthesis by Microwave Irradiation." Molekul 15, no. 1 (March 23, 2020): 56. http://dx.doi.org/10.20884/1.jm.2020.15.1.564.

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Graphene has been attracting enormous attention in the scientific community because of its unique properties and use for various applications. Graphene has been synthesized in various ways, one of which is the graphite oxidation method to form graphene oxide (GO). Reduction of GO to reduced graphene oxide (RGO) is necessary to recover the conjugated network and electrical conductivity, and for this research, this was achieved using microwave irradiation. Microwave synthesis provides an alternative method, saving more time in the reaction process. In this research, graphene was synthesized from graphite by the modified Hummers method and microwave irradiation. This research proves that graphene can be synthesized with a high-quality structure and in a shorter amount of time using microwave irradiation to reduce GO. With longer microwave exposure, less GO is present in the sample, as indicated by the absence of an n–π* electronic transition in the absorbance graph and the absence of oxide groups in the Fourier-Transform Infra-Red spectrum. With increasing microwave power, the reduction process is short-lived, and better quality RGO is produced. This study shows that the new reduction process occurs within 20 minutes with a power of 450 and 630 watts, but at 900 watts, the reduction of GO occurs within 10 minutes, as shown by UV-Vis and FTIR spectra.

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Wang, XiaoDong, JianChao Wang, Swarup Biswas, Hyeok Kim, and IlWoo Nam. "Mechanical, Electrical, and Piezoresistive Sensing Characteristics of Epoxy-Based Composites Incorporating Hybridized Networks of Carbon Nanotubes, Graphene, Carbon Nanofibers, or Graphite Nanoplatelets." Sensors 20, no. 7 (April 8, 2020): 2094. http://dx.doi.org/10.3390/s20072094.

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The present study compared the mechanical, electrical, morphological, and piezoresistive characteristics of epoxy-based sensing nanocomposites fabricated with inclusions of hybridized networks of four different carbon nanomaterials (CNMs), such as carbon nanotube (CNT), graphene, carbon nanofiber (CNF), and graphite nanoplatelet (GNP). Enhancements in elastic modulus and electrical conductivity were achieved by CNT–graphene composites and CNT–CNF composites, and these were explained by the morphological observations carried out in the present study and experimental studies found in the literature. The greatest gauge factor was accomplished by the CNT–GNP composite, followed by the CNT–CNF composite among composites where the CNM networks were sufficiently formed with a content ratio of 3%. The two types of the composites outperformed the composites incorporating solely CNT in terms of gauge factor, and this superiority was explained with the excluded volume theory.

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Phan, Anh D., Cuong V. Nguyen, Pham T. Linh, Tran V. Huynh, Vu D. Lam, Anh-Tuan Le, and Katsunori Wakabayashi. "Deep Learning for the Inverse Design of Mid-Infrared Graphene Plasmons." Crystals 10, no. 2 (February 19, 2020): 125. http://dx.doi.org/10.3390/cryst10020125.

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We theoretically investigate the plasmonic properties of mid-infrared graphene-based metamaterials and apply deep learning of a neural network for the inverse design. These artificial structures have square periodic arrays of graphene plasmonic resonators deposited on dielectric thin films. Optical spectra vary significantly with changes in structural parameters. To validate our theoretical approach, we carry out finite difference time domain simulations and compare computational results with theoretical calculations. Quantitatively good agreements among theoretical predictions, simulations, and previous experiments allow us to employ this proposed theoretical model to generate reliable data for training and testing deep neural networks. By merging the pre-trained neural network with the inverse network, we implement calculations for inverse design of the graphene-based metameterials. We also discuss the limitation of the data-driven approach.

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Iijima, Sumio. "Closed graphene nanostructures." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 194–95. http://dx.doi.org/10.1017/s0424820100137343.

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Graphene is named a single sheet of graphite, or a 2-D carbon hexagons network. The graphene structure has been observed in partially graphitized carbon which is familiar to electron microscopists and its HRTEM image properties were analyzed previously in detail. C60 molecules, which has brought a great excitements in interdisciplinary fields of science and technology, is basically the same graphene structure with a curvature. The individual C60 molecule can be imaged without difficulty by HRTEM. Many of fundamental problems with the molecule however are not solved by the HRTEM technique. On the other hand, carbon nanotubes, a family of the fullerene and discovered serendipitously by the present author5, are an ideal subject for the HRTEM investigation and in fact their structural details can only be analyzed by this technique. The present talk reviews the carbon nanotubes and related structures with an emphasis of usefulness of the HRTEM.Search for the multi-shell graphite particles leads to unexpected discovery of carbon nanotubes which grow on a cathode in a carbon-arc chamber for the C60 production.

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Neri, Giulia, Enza Fazio, Placido Giuseppe Mineo, Angela Scala, and Anna Piperno. "SERS Sensing Properties of New Graphene/Gold Nanocomposite." Nanomaterials 9, no. 9 (August 30, 2019): 1236. http://dx.doi.org/10.3390/nano9091236.

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The development of graphene (G) substrates without damage on the sp2 network allows to tune the interactions with plasmonic noble metal surfaces to finally enhance surface enhanced Raman spectroscopy (SERS) effect. Here, we describe a new graphene/gold nanocomposite obtained by loading gold nanoparticles (Au NPs), produced by pulsed laser ablation in liquids (PLAL), on a new nitrogen-doped graphene platform (G-NH2). The graphene platform was synthesized by direct delamination and chemical functionalization of graphite flakes with 4-methyl-2-p-nitrophenyl oxazolone, followed by reduction of p-nitrophenyl groups. Finally, the G-NH2/Au SERS platform was prepared by using the conventional aerography spraying technique. SERS properties of G-NH2/Au were tested using Rhodamine 6G (Rh6G) and Dopamine (DA) as molecular probes. Raman features of Rh6G and DA are still detectable for concentration values down to 1 × 10−5 M and 1 × 10−6 M respectively.

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Kumar, Harish V., Andrew J. Oyer, Kevin Y. S. Huang, and Douglas H. Adamson. "Evolution of Heterogeneity and Chemical Functionality during the Oxidation of Graphite." Colloids and Interfaces 6, no. 3 (August 29, 2022): 44. http://dx.doi.org/10.3390/colloids6030044.

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A kinetic study of graphite oxidation provided several insights into the mechanism of graphite oxide (GO) synthesis. The oxidation was observed to occur in two distinct stages, with the first stage lasting for 20 to 30 min and including a rapid disruption of the graphene sp2 network, the introduction of oxygen functional groups, and an increase in the spacing between the sheets. The second stage saw a marked decrease in the rate of change in spacing, a significant increase in the homogeneity of the GO, little to no further disruption of the sp2 network, and continuing evolution of the oxygen functionality. The study was based on the analysis by Raman spectroscopy, XRD, FTIR, SEM, and TGA of material taken at various times from a modified Hummers oxidation reaction following work up.

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Milashius, Viktoria, Volodymyr Pavlyuk, Karolina Kluziak, Grygoriy Dmytriv, and Helmut Ehrenberg. "LiBC3: a new borocarbide based on graphene and heterographene networks." Acta Crystallographica Section C Structural Chemistry 73, no. 11 (October 24, 2017): 984–89. http://dx.doi.org/10.1107/s2053229617015182.

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Li–B–C alloys have attracted much interest because of their potential use in lithium-ion batteries and superconducting materials. The formation of the new compound LiBC3 [lithium boron tricarbide; own structure type, space group P\overline{6}m2, a = 2.5408 (3) Å and c = 7.5989 (9) Å] has been revealed and belongs to the graphite-like structure family. The crystal structure of LiBC3 presents hexagonal graphene carbon networks, lithium layers and heterographene B/C networks, alternating sequentially along the c axis. According to electronic structure calculations using the tight-binding linear muffin-tin orbital-atomic spheres approximations (TB–LMTO–ASA) method, strong covalent B—C and C—C interactions are established. The coordination polyhedra for the B and C atoms are trigonal prisms and for the Li atoms are hexagonal prisms.

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Wu, Jie, Saima Nazeer, Iftikhar Ahmed, and Farkhanda Yasmin. "Study of Graphene Networks and Line Graph of Graphene Networks via NM-Polynomial and Topological Indices." Journal of Mathematics 2022 (November 12, 2022): 1–42. http://dx.doi.org/10.1155/2022/3809806.

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The topological invariants are related to the molecular graph of the chemical structure and are numerical numbers that help us to understand the topology of the concerned chemical structure. With the help of these numbers, many properties of graphene can be guessed without preforming any experiment. Huge amount of calculations are required to obtain topological invariants for graphene, but by applying basic calculus roles, neighborhood M -polynomial of graphene gives its indices. The aim of this work is to compute neighborhood degree-dependent indices for the graph of graphene and the line graph of subdivision graph of graphene. Firstly, we establish neighborhood M-polynomial of these families of graphs, and then, by applying basic calculus, we obtain several neighborhood degree-dependent indices. Our results play an important role to understand graphene and enhance its abilities.

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De Feyter, Steven. "(Invited, Digital Presentation) Molecular Self-assembly and Reactivity on 2D Layered Materials." ECS Meeting Abstracts MA2022-01, no. 12 (July 7, 2022): 860. http://dx.doi.org/10.1149/ma2022-0112860mtgabs.

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In the first part, we will focus on the principles of self-assembled molecular network formation at the liquid-solid interface on surfaces such as graphite, MoS2, and graphene. Then we will discuss how lateral confinement, induced by covalent functionalization of graphite and graphene, affects self-assembly. Several strategies will be demonstrated to realize two-dimensional lateral confinement, all based on the covalent modification of the surface, making use of bottom-up approaches or a combination of bottom-up and top-down approaches. The impact of these various types of confinement on the formation of self-assembled molecular networks will be discussed, including aspects such as nucleation and growth, directional self-assembly, on-surface chirality, polymorphism, and reactivity. In a second part, we will focus on the formation of porous two-dimensional covalent organic frameworks at the liquid-solid interface, and reveal various interesting aspects at the molecular level such as nucleation and growth mechanisms, and the impact local electric fields may have on (de)polymerization processes. The relevance and importance of scanning probe microscopes to investigate (and control) self-assembly and reactivity on surfaces will be illustrated. C. Rodríguez González, A. Leonhardt, H. Stadler, S. Eyley, W. Thielemans, S. De Gendt, K. S. Mali, S. De Feyter, ACS Nano, 2021, 15, 10618–10627 Verstraete, S. De Feyter, Chem. Soc. Rev., Chemical Society Reviews, 2021, 50, 5884–5897 Bragança, A. Minoia, R. Steeno, J. Seibel, B. E. Hirsch, L. Verstraete, O. Ivasenko, K. Müllen, K. S. Mali, R. Lazzaroni, S. De Feyter, J. Am. Chem. Soc., 2021, 143, 11080–11087 Tahara, Y. Kubo, S. Hashimoto, T. Ishikawa, H. Kaneko, A. Brown, B. E. Hirsch, S. De Feyter, Y. Tobe, J. Am. Chem. Soc., 2020, 142, 7699–7708 Zhan, Z.-F. Cai, M. Martínez-Abadía, A. Mateo-Alonso, S. De Feyter, J. Am. Chem. Soc. 2020, 142, 5964–5968

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ZENG, BIN, YOUXIN LUO, QIYUAN LIU, and WUJUN ZENG. "CARBON NANOTUBES/GRAPHENE THREE-DIMENSIONAL NETWORKS ARCHITECTURE LOADING WITH Ni AND ITS ADSORPTION PROPERTIES." Nano 09, no. 02 (February 2014): 1450019. http://dx.doi.org/10.1142/s1793292014500192.

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The composite of carbon nanotubes/graphene networks loaded- Ni (CNTs/GR- Ni ) were successfully synthesized by spray drying and post-calcinating method for the first time. The synthesized products were systematically studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The result showed the hybrid of CNTs and graphene composed the 3D network structure and Ni nanoparticles were attaching on their surface. Adsorption performance evidenced that the obtained nanocomposite possessed high adsorption efficiency and excellent separation property.

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Ma, Yanfeng, and Yongsheng Chen. "Three-dimensional graphene networks: synthesis, properties and applications." National Science Review 2, no. 1 (December 17, 2014): 40–53. http://dx.doi.org/10.1093/nsr/nwu072.

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Abstract Recently, three-dimensional graphene/graphene oxide (GO) networks (3DGNs) in the form of foams, sponges and aerogels have attracted much attention. 3D structures provide graphene materials with high specific surface areas, large pore volumes, strong mechanical strengths and fast mass and electron transport, owing to the combination of the 3D porous structures and the excellent intrinsic properties of graphene. This review focuses on the latest advances in the preparation, properties and potential applications of 3D micro-/nano-architectures made of graphene/GO-based networks, with emphasis on graphene foams and sponges.

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Wang, Jilong, Junhua Wei, Siheng Su, and Jingjing Qiu. "Tough and Fatigue-Resistant Hydrogels with Triple Interpenetrating Networks." Journal of Nanomaterials 2019 (February 25, 2019): 1–15. http://dx.doi.org/10.1155/2019/6923701.

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Biomimetic hydrogels with triple networks have been developed via in situ polymerization and addition of graphene oxide (GO) nanosheets, which achieve improved toughness and superior fatigue resistance, simultaneously. Compared with pristine calcium alginate/polyacrylamide double network (DN) hydrogels, the integration of a calcium-induced graphene oxide network enhances the crosslinking degree of triple network (TN) hydrogels with improved compressive strength by 172% and toughness by 174%. In addition, cyclic compressive loading-unloading curves depict excellent fatigue resistance because of reversible calcium alginate and calcium-induced GO networks, whereas high strength and toughness of traditional DN gels derive from the first sacrificial network, which leads to inferior fatigue resistance. Toughness of these TN gels was still kept at 110 kJ m−3 at the fifth cycle which is equal to that of articular cartilages. The swelling property of these DN and TN hdyrogels is also systematically explored, which exhibits that GO can reduce the swelling to maintain the mechanical properties of TN gels. The internal fracture mechanisms of these TN hydrogels are studied via swelling tests of precompressed and as-prepared gels. These synergistic effects of the reversible ions crosslinking polymer network and nanofillers open a new platform to design supertough and fatigue-resistant hydrogels. In addition, these TN hydrogels are talented replacements for load-bearing parts, like cartilage due to its high toughness and superior fatigue resistance.

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Marquez, Bicky A., Hugh Morison, Zhimu Guo, Matthew Filipovich, Paul R. Prucnal, and Bhavin J. Shastri. "Graphene-based photonic synapse for multi wavelength neural networks." MRS Advances 5, no. 37-38 (2020): 1909–17. http://dx.doi.org/10.1557/adv.2020.327.

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AbstractA synapse is a junction between two biological neurons, and the strength, or weight of the synapse, determines the communication strength between the neurons. Building a neuromorphic (i.e. neuron isomorphic) computing architecture, inspired by a biological network or brain, requires many engineered synapses. Furthermore, recent investigation in neuromorphic photonics, i.e. neuromorphic architectures on photonics platforms, have garnered much interest to enable high-bandwidth, low-latency, low-energy applications of neural networks in machine learning and neuromorphic computing. We propose a graphene-based synapse model as a core element to enable large-scale photonic neural networks based on on-chip multiwavelength techniques. This device consists of an electro-absorption modulator embedded in a microring resonator. We also introduce an encoding protocol that allows for the representation of synaptic weights on our photonic device with 15.7 bits of resolution using current control hardware. Recent work has suggested that graphene-based modulators could operate in excess of 100 GHz. Combined with our work, such a graphene-based synapse could enable applications for ultrafast and online learning.

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Guo, Rui, Zechun Ren, Hongjie Bi, Min Xu, and Liping Cai. "Electrical and Thermal Conductivity of Polylactic Acid (PLA)-Based Biocomposites by Incorporation of Nano-Graphite Fabricated with Fused Deposition Modeling." Polymers 11, no. 3 (March 22, 2019): 549. http://dx.doi.org/10.3390/polym11030549.

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The aim of the study was to improve the electrical and thermal conductivity of the polylactic acid/wood flour/thermoplastic polyurethane composites by Fused Deposition Modeling (FDM). The results showed that, when the addition amount of nano-graphite reached 25 pbw, the volume resistivity of the composites decreased to 108 Ω·m, which was a significant reduction, indicating that the conductive network was already formed. It also had good thermal conductivity, mechanical properties, and thermal stability. The adding of the redox graphene (rGO) combined with graphite into the composites, compared to the tannic acid-functionalized graphite or the multi-walled carbon nanotubes, can be an effective method to improve the performance of the biocomposites, because the resistivity reduced by one order magnitude and the thermal conductivity increased by 25.71%. Models printed by FDM illustrated that the composite filaments have a certain flexibility and can be printed onto paper or flexible baseplates.

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Ziatdinov, Albert M., and Peter G. Skrylnik. "Films of Reduced Graphene Oxide with Percolation Networks of Nanographenes." Defect and Diffusion Forum 386 (September 2018): 388–93. http://dx.doi.org/10.4028/www.scientific.net/ddf.386.388.

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Percolation networks of electrically connected nanographenes are the promising structures for solving the problem of the transfer of their peculiar quantum properties to the macroscopic level. In this work we report the results of investigations, conducted with using a set of complementary physical methods, on the origin, structural motifs and properties of such networks revealed in thermally reduced graphene oxide films. The presence of zero modes, which may be π-electronic states stabilized at the zigzag edges of network elements, has been established.

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Shekar, S. Chandra, and R. S. Swathi. "Cation−π Interactions and Rattling Motion through Two-Dimensional Carbon Networks: Graphene vs Graphynes." Journal of Physical Chemistry C 119, no. 16 (April 8, 2015): 8912–23. http://dx.doi.org/10.1021/jp512593r.

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Barbera, Vincenzina, Giulio Torrisi, and Maurizio Galimberti. "Bionanocomposites based on a covalent network of chitosan and edge functionalized graphene layers." Journal of Applied Biomaterials & Functional Materials 19 (January 2021): 228080002110174. http://dx.doi.org/10.1177/22808000211017431.

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In this study, carbon papers and aerogels were prepared from chitosan and graphene layers with aldehydic edge functional groups (G-CHO) able to form chemical bonds with chitosan and thus to form a crosslinked network. A high surface area graphite was edge functionalized with hydroxyl groups (G-OH) through the reaction with KOH. G-CHO, with 4.5 mmol/g of functional group, was prepared from G-OH by means of the Reimer-Tieman reaction. Characterization of the graphitic materials was performed with elemental analysis, titration, X-ray analysis, Raman spectroscopy and by estimating their Hansen solubility parameters. CS and G-CHO were mixed with mortar and pestle and carbon papers and aerogels were obtained from a stable acidic water suspension through casting and liophilization, respectively. Free standing and foldable carbon papers and monolithic aerogels based on a continuous covalent network between G-CHO and CS were prepared. G-CHO, which had about 22 stacked layers, was extensively exfoliated in the carbon paper, as confirmed by the absence of the 002 reflection of the graphitic crystallites in the XRD pattern. Carbon paper was found to be resistant to solvents and to be stable for pH ⩾ 7. Composites revealed electrical conductivity. The covalent network between the graphene layers and CS, suggested by the IR findings, accounts for these results. This work demonstrates the effectiveness of a continuous covalent network between chitosan and graphene layers edge functionalized with tailor made functional groups for the preparation of carbon papers and aerogels and paves the way for the scale up of such a type of composites.

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Planillo, Jordan, and Fabio Alves. "Fabrication and Characterization of Micrometer Scale Graphene Structures for Large-Scale Ultra-Thin Electronics." Electronics 11, no. 5 (March 1, 2022): 752. http://dx.doi.org/10.3390/electronics11050752.

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Graphene offers many useful properties that can revolutionize modern electronic devices. Specifically, it provides high charge carrier mobility in a mechanically robust, atomically thin form factor. Many of these properties are observed in graphene which is prepared from exfoliated graphite and processed with electron beam lithography. These processes are both time intensive and cost- prohibitive for the large-scale production necessary for use in consumer electronics. This work details the processing and characterization of commercially available graphene from chemical vapor deposition (CVD) on SiO2/Si and on hBN-layered SiO2/Si wafers using conventional photolithography on the 4″ wafer standard. The findings indicate that the CVD graphene films are resilient after processing even for lengths up to 1 mm. Electrical characterization via resistance measurements and the Hall Effect at room temperature clearly indicates the influence of the substrate material on the graphene’s electrical properties. At these length scales, graphene on SiO2 resembles that of a lightly doped semiconductor in terms of its carrier density (7.8 × 1015 cm−2), yet its carrier mobility (2.6 cm2/Vs) resembles that of a metal. Graphene on hBN/SiO2 has a carrier density of 8.2 × 1012 cm−2 and carrier mobility of 2.68 × 103 cm2/Vs—comparable to existing high-mobility semiconducting materials. CVD graphene and conventional photolithography does provide a cost-effective means for producing large form-factor graphene devices for low to moderate mobility applications and eventually for large-scale monolithic graphene electronics.

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Ghosal, Supriya, and Debnarayan Jana. "Beyond T-graphene: Two-dimensional tetragonal allotropes and their potential applications." Applied Physics Reviews 9, no. 2 (June 2022): 021314. http://dx.doi.org/10.1063/5.0088275.

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Breakthrough of graphene dictates that decreasing dimensionality of the semiconducting materials can generate unusual electronic structures, excellent mechanical, and thermal characteristics with remarkable stability. Silicene, germanene, and stanene are the next 2D stable counterparts of other elements belonging to the same group. Since these monolayers possess hexagonal symmetry, scientists had already explored the possibility in the post graphene era of whether hexagonal symmetry was the main and utmost criterion for achieving Dirac cone. This motivation gave birth to T-graphene, a tetragonal network comprised of carbon atoms. However, T-graphene is not the only candidate for exhibiting Dirac fermion. In recent days, tetragonal monolayers of Si and Ge, i.e., T-Si and T-Ge, have been predicted to be stable. These 2D tetragonal allotropes remarkably possess double Dirac cones in their electronic band structure. As these monolayers possess buckling similar to silicene and germanene, the electronic bandgap can be easily introduced in the presence of an external electric field. Another technique to open bandgap is to apply strain in hydrogenated tetragonal networks. Tunable electronic properties in these tetragonal systems make them efficient for optoelectronics as well as thermoelectric applications. Moreover, due to delocalized π electrons, quantum dot systems comprised of tetragonal Si and Ge network show remarkable characteristics in the field of nonlinear optics. Recently, based on theoretical calculations, a bilayer T-graphene system is predicted with excellent mechanical strength relative to its monolayer variant. Not only group-IVA, group-VA elements also exhibit stable monolayer structures. Rather than T-graphene, T-Si, and T-Ge, these monolayers, however, possess intrinsic semiconducting properties, which enable them as a potential candidate for optoelectronic applications. Furthermore, several possible routes have been introduced to realize these systems experimentally. In this topical Review, we would critically explore the recent advancements of 2D tetragonal networks containing group-IVA and VA elements and their possible application perspectives in the field of thermoelectrics and nano-photonics.

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Kim, Sunnam, Sho Moriya, Sakura Maruki, Tuyoshi Fukaminato, Tomonari Ogata, and Seiji Kurihara. "Adsorption and release on three-dimensional graphene oxide network structures." Royal Society Open Science 8, no. 5 (May 2021): 201585. http://dx.doi.org/10.1098/rsos.201585.

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In this study, three-dimensional network architectures are constructed using nano-sized graphene oxide (nGO) as the building block. The cross-linking reaction of nGO is conducted in sub-micrometre water droplets in an emulsion system to control the size of the networks by restricting the reaction space. Two types of three-dimensional GO networks with different cross-linking lengths were constructed, and their methyl orange adsorption and release behaviours were investigated under external stimuli, such as thermal treatment, ultrasonic wave treatment and near-infrared light irradiation.

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KardanMoghaddam, Hossein, Mohamadreza Maraki, and Amir Rajaei. "Graphene-reinforced polymeric nanocomposites in computer and electronics industries." Facta universitatis - series: Electronics and Energetics 33, no. 3 (2020): 351–78. http://dx.doi.org/10.2298/fuee2003351m.

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Graphene is the newest member of the multidimensional graphite carbon family. Graphene is a two-dimensional atomic crystal formed by the arrangement of carbon atoms in the hexagonal network. It is the most rigid and thinnest material ever discovered and has a wide range of uses regarding its unique characteristics. It is expected that this material will create a revolution in the electronics industry. Graphene is a very powerful superconductor as the movability of charged particles is high on it, and additionally, because of the high surface energy and ? electrons being free, graphene can be used in manufacturing many electronics devices. In this paper, the applications of graphene nanoparticles reinforced polymer nanocomposites in the computer and electronics industry are investigated. These nanoparticles have received much attention from researchers and craftsmen, because graphene has unique thermal, electrical and mechanical properties. Its use as a filler in very small quantities substantially enhances the properties of nanocomposites. There are various methods for producing graphene-reinforced polymer nanocomposites. These methods affect the amount of graphene dispersion within the polymer substrate and the final properties of the composite. The application and the properties of graphene-reinforced polymer nanocomposites are discussed along with examples of results published in the papers. To better understand such materials, the applications of these nanocomposites have been investigated in a variety of fields, including batteries, capacitors, sensors, solar cells, etc., and the barriers to the growth and development of these materials application as suggested by the researchers are discussed. As the use of these nanocomposites is developing and many researchers are interested in working on it, the need to study and deal with these substances is increasingly felt.

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Zhang, Xiao, Jian Zheng, Yong Qiang Du, and Chun Ming Zhang. "Three-Dimensional Graphite Filled Poly(Vinylidene Fluoride) Composites with Enhanced Strength and Thermal Conductivity." Key Engineering Materials 842 (May 2020): 63–68. http://dx.doi.org/10.4028/www.scientific.net/kem.842.63.

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Three-dimensional (3D) network structure has been recognized as an efficient approach to enhance the mechanical and thermal conductive properties of polymeric composites. However, it has not been applied in energetic materials. In this work, a fluoropolymer based composite with vertically oriented and interconnected 3D graphite network was fabricated for polymer bonded explosives (PBXs). Here, the graphite and graphene oxide platelets were mixed, and self-assembled via rapid freezing and using crystallized ice as the template. The 3D structure was finally obtained by freezing-dry, and infiltrating with polymer. With the increasing of filler fraction and cooling rate, the thermal conductivity of the polymer composite was significantly improved to 2.15 W m-1 K-1 by 919% than that of pure polymer. Moreover, the mechanical properties, such as tensile strength and elastic modulus, were enhanced by 117% and 563%, respectively, when the highly ordered structure was embedded in the polymer. We attribute the increased thermal and mechanical properties to this 3D network, which is beneficial to the effective heat conduction and force transfer. This study supports a desirable way to fabricate the strong and thermal conductive fluoropolymer composites used for the high-performance polymer bonded explosives (PBXs).

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Obrzut, Jan, Denis Pristinski, and Mitra Yoonessi. "Optical and Electrical Properties of Graphene Percolated Networks from Liquid Exfoliation of Graphite." ECS Transactions 28, no. 5 (December 17, 2019): 99–106. http://dx.doi.org/10.1149/1.3367941.

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Wu, Qiupeng, Zhiheng Yu, Fengli Huang, and Jinmei Gu. "Electrospun PA66/Graphene Fiber Films and Application on Flexible Triboelectric Nanogenerators." Materials 15, no. 15 (July 26, 2022): 5191. http://dx.doi.org/10.3390/ma15155191.

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Triboelectric nanogenerators (TENGs) are considered to be the most promising energy supply equipment for wearable devices, due to their excellent portability and good mechanical properties. Nevertheless, low power generation efficiency, high fabrication difficulty, and poor wearability hinder their application in the wearable field. In this work, PA66/graphene fiber films with 0, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt% graphene and PVDF films were prepared by electrospinning. Meanwhile, TENGs were prepared with PA66/graphene fiber films, PVDF films and plain weave conductive cloth, which were used as the positive friction layer, negative friction layer and the flexible substrate, respectively. The results demonstrated that TENGs prepared by PA66/graphene fiber films with 2 wt% grapheme showed the best performance, and that the maximum open circuit voltage and short circuit current of TENGs could reach 180 V and 7.8 μA, respectively, and that the power density was 2.67 W/m2 when the external load was 113 MΩ. This is why the PA66/graphene film produced a more subtle secondary network with the addition of graphene, used as a charge capture site to increase its surface charge. Additionally, all the layered structures of TENGs were composed of breathable electrospun films and plain conductive cloth, with water vapor transmittance (WVT) of 9.6 Kgm−2d−1, reflecting excellent wearing comfort. The study showed that TENGs, based on all electrospinning, have great potential in the field of wearable energy supply devices.

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Kandasamy, Senthil Kumar, Chandrasekaran Arumugam, A. S. Sajitha, Saggurthi Prabhakara Rao, Sangavi Selvaraj, Ragavi Vetrivel, Roobak Selvarajan, et al. "Paradisiaca/Solanum Tuberosum Biowaste Composited with Graphene Oxide for Flexible Supercapacitor." Journal of New Materials for Electrochemical Systems 24, no. 1 (March 31, 2021): 21–28. http://dx.doi.org/10.14447/jnmes.v24i1.a04.

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This work focuses on the development of a novel type of chemically activated carbon networks composited with the graphene oxide. Here, the carbon networks were derived from green biomass wastes such as orange peels, banana peels and potato starch. All the obtained carbon materials were being activated using different activating agents based on the higher specific capacitance such as phosphoric acid activated orange peel derived carbon, sulphuric acid activated banana peel derived carbon and hydrochloric acid activated potato starch. Further they were individually composited with graphene oxide for enhanced performance. Different chemical activation is employed for the sake of obtaining higher specific capacitance, energy and power density. Phosphoric acid activation on orange peel derived carbon network was selected due to the improvement in the micropores and further increased the surface area with the controlling capability of structures of activated carbon. To improve the conductivity of the samples, graphene oxide was added. The electrochemical performance of orange peel, banana peel and potato starch derived nano porous activated carbon materials composited with graphene oxide for supercapacitor applications is evaluated using aqueous H2SO4 electrolytes at a scan rate of 10 mV s-1. The samples that are prepared are structurally characterized using fourier transform infrared spectroscopy, x-ray diffraction and electrochemically characterized using cyclic voltammetry, galvanostatic charge and discharge measurements, and electrochemical impedance spectroscopy. From the electrochemical measurements, suitability of material as electrode for supercapacitors can be understood. The superior electrochemical performance is attributed in orange peel derived nano porous carbon/ graphene oxide due to porous structure.

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Kim, Jaegyeong, Changil Oh, Changju Chae, Dae-Hoon Yeom, Jaeho Choi, Nahyeon Kim, Eun-Suok Oh, and Jung Kyoo Lee. "3D Si/C particulate nanocomposites internally wired with graphene networks for high energy and stable batteries." Journal of Materials Chemistry A 3, no. 36 (2015): 18684–95. http://dx.doi.org/10.1039/c5ta04681e.

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Novel 3D particulate Si/C-IWGNs (Si/C composites internally wired with graphene networks), in which graphene networks not only provide electrical networks but generate void spaces, showed stable cycling behavior at high capacity with a small increase in electrode thickness.

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Journal articles on the topic 'Graphyne networks'

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