Graphene morphology

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A graphene morphology is any of the structures related to, and formed from, single sheets of graphene. 'Graphene' is typically used to refer to the crystalline monolayer of the naturally occurring material graphite. Due to quantum confinement of electrons within the material at these low dimensions, small differences in graphene morphology can greatly impact the physical and chemical properties of these materials. Commonly studied graphene morphologies include the monolayer sheets, bilayer sheets, graphene nanoribbons and other 3D structures formed from stacking of the monolayer sheets.

Contents

Monolayer sheets

In 2013 researchers developed a production unit that produces continuous monolayer sheets of high-strength monolayer graphene (HSMG). [1] The process is based on graphene growth on a liquid metal matrix. [2]

Bilayer

Bilayer graphene displays the anomalous quantum Hall effect, a tunable band gap [3] and potential for excitonic condensation. [4] Bilayer graphene typically can be found either in twisted configurations where the two layers are rotated relative to each other or graphitic Bernal stacked configurations where half the atoms in one layer lie atop half the atoms in the other. [5] Stacking order and orientation govern its optical and electronic properties.

One synthesis method is chemical vapor deposition, which can produce large bilayer regions that almost exclusively conform to a Bernal stack geometry. [5]

Superlattices

Periodically stacked graphene and its insulating isomorph provide a fascinating structural element in implementing highly functional superlattices at the atomic scale, which offers possibilities in designing nanoelectronic and photonic devices. Various types of superlattices can be obtained by stacking graphene and its related forms. [6] [7] The energy band in layer-stacked superlattices is more sensitive to the barrier width than that in conventional III–V semiconductor superlattices. When adding more than one atomic layer to the barrier in each period, the coupling of electronic wavefunctions in neighboring potential wells can be significantly reduced, which leads to the degeneration of continuous subbands into quantized energy levels. When varying the well width, the energy levels in the potential wells along the L–M direction behave distinctly from those along the K–H direction.

Precisely aligned graphene on h-BN always produces giant superlattice known as Moiré pattern. [8] Moiré patterns are observed and the sensitivity of moiré interferometry proves that the graphene grains can align precisely with the underlying h-BN lattice within an error of less than 0.05°. The occurrence of moiré pattern clearly indicates that the graphene locks into h-BN via van der Waals epitaxy with its interfacial stress greatly released.

The existence of the giant Moiré pattern in graphene nanoribbon (GNR) embedded in hBN indicates that the graphene was highly crystalline and precisely aligned with the h-BN underneath. It was noticed that the Moiré pattern appeared to be stretched along the GNR, while it appeared relaxed laterally. [9] This trend differs from regular hexagons with a periodicity of ~14 nm, which have always been observed with well-aligned graphene domains on h-BN. This observation gives a strong indication of the in-plane epitaxy between the graphene and the h-BN at the edges of the trench, where the graphene is stretched by tensile strain along the ribbon, due to a lattice mismatch between the graphene and h-BN.

Nanoribbons

Graphene nanoribbons ("nanostripes" in the "zig-zag" orientation), at low temperatures, show spin-polarized metallic edge currents, which suggest spintronics applications. (In the "armchair" orientation, the edges behave like semiconductors. [10] )

Fiber

In 2011, researchers reported making fibers using chemical vapor deposition grown graphene films. [11] The method was scalable and controllable, delivering tunable morphology and pore structure by controlling the evaporation of solvents with suitable surface tension. Flexible all-solid-state supercapacitors based on such fibers were demonstrated in 2013. [12]

In 2015 intercalating small graphene fragments into the gaps formed by larger, coiled graphene sheets after annealing provided pathways for conduction, while the fragments helped reinforce the fibers.[ sentence fragment ] The resulting fibers offered better thermal and electrical conductivity and mechanical strength. Thermal conductivity reached 1290 watts per meter per kelvin, while tensile strength reached 1080 megapascals. [13]

In 2016, kilometer-scale continuous graphene fibers with outstanding mechanical properties and excellent electrical conductivity were produced by high-throughput wet-spinning of graphene oxide liquid crystals followed by graphitization through a full-scale synergetic defect-engineering strategy. [14]

3D

Three dimensional bilayer graphene was reported in 2012 [15] and 2014. [16]

In 2013, a three-dimensional honeycomb of hexagonally arranged carbon was termed 3D graphene. Self-supporting 3D graphene was produced that year. [17] Researchers at Stony Brook University have reported a novel radical-initiated crosslinking method to fabricate porous 3D free-standing architectures of graphene and carbon nanotubes using nanomaterials as building blocks without any polymer matrix as support. [18] 3D structures can be fabricated by using either CVD or solution-based methods. A 2016 review summarized the techniques for fabrication of 3D graphene and other related two-dimensional materials. [19] These 3D graphene (all-carbon) scaffolds/foams have potential applications in fields such as energy storage, filtration, thermal management and biomedical devices and implants. [19] [20]

In 2016, a box-shaped graphene (BSG) nanostructure resulted from mechanical cleavage of pyrolytic graphite has been reported. [21] The discovered nanostructure is a multilayer system of parallel hollow nanochannels located along the surface that displayed quadrangular cross-section. The thickness of the channel walls is approximately equal to 1 nm, the typical width of channel facets makes about 25 nm. Potential applications include: ultra-sensitive detectors, high-performance catalytic cells, nanochannels for DNA sequencing and manipulation, high-performance heat sinking surfaces, rechargeable batteries of enhanced performance, nanomechanical resonators, electron multiplication channels in emission nanoelectronic devices, high-capacity sorbents for safe hydrogen storage.

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Gyroid

In 2017 researchers simulated a graphene gyroid that has five percent of the density of steel, yet is ten times as strong with an enormous surface area to volume ratio. They compressed heated graphene flakes. They then constructed high resolution 3D-printed models of plastic of various configurations – similar to the gyroids that graphene form naturally, though thousands of times larger. These shapes were then tested for tensile strength and compression, and compared to the computer simulations. When the graphene was swapped out for polymers or metals, similar gains in strength were seen. [22] [23]

A film of graphene soaked in solvent to make it swell and become malleable was overlaid on an underlying substrate "former". The solvent evaporated, leaving behind a layer of graphene that had taken on the shape of the underlying structure. In this way the team[ who? ] was able to produce a range of relatively intricate micro-structured shapes. [24] Features vary from 3.5 to 50 μm. Pure graphene and gold-decorated graphene were each successfully integrated with the substrate. [25]

An aerogel made of graphene layers separated by carbon nanotubes was measured at 0.16 milligrams per cubic centimeter. A solution of graphene and carbon nanotubes in a mold is freeze dried to dehydrate the solution, leaving the aerogel. The material has superior elasticity and absorption. It can recover completely after more than 90% compression, and absorb up to 900 times its weight in oil, at a rate of 68.8 grams per second. [26]

At the end of 2017, fabrication of freestanding graphene gyroids with 35nm and 60nm unit cells was reported. [27] The gyroids were made via controlled direct chemical vapor deposition and are self-supporting and can be transferred onto a variety of substrates. Furthermore, they represent the smallest free standing periodic graphene 3D structures yet produced with a pore size of tens of nm. Due to their high mechanical strength, good conductivity (sheet resistance  : 240 Ω/sq) and huge ratio of surface area per volume, the graphene gyroids might find their way to various applications, ranging from batteries and supercapacitors to filtration and optoelectronics.

Pillared

Pillared graphene is a hybrid carbon structure consisting of an oriented array of carbon nanotubes connected at each end to a graphene sheet. It was first described theoretically in 2008. Pillared graphene has not been synthesized in the laboratory.

Reinforced

Graphene sheets reinforced with embedded carbon nanotubes ("rebar") are easier to manipulate, while improving the electrical and mechanical qualities of both materials. [28] [29]

Functionalized single- or multiwalled carbon nanotubes are spin-coated on copper foils and then heated and cooled, using the nanotubes as the carbon source. Under heating, the functional carbon groups decompose into graphene, while the nanotubes partially split and form in-plane covalent bonds with the graphene, adding strength. π–π stacking domains add more strength. The nanotubes can overlap, making the material a better conductor than standard CVD-grown graphene. The nanotubes effectively bridge the grain boundaries found in conventional graphene. The technique eliminates the traces of substrate on which later-separated sheets were deposited using epitaxy. [28]

Stacks of a few layers have been proposed as a cost-effective and physically flexible replacement for indium tin oxide (ITO) used in displays and photovoltaic cells. [28]

Nanocoil

In 2015 a coiled form of graphene was discovered in graphitic carbon (coal). The spiraling effect is produced by defects in the material's hexagonal grid that causes it to spiral along its edge, mimicking a Riemann surface, with the graphene surface approximately perpendicular to the axis. When voltage is applied to such a coil, current flows around the spiral, producing a magnetic field. The phenomenon applies to spirals with either zigzag or armchair orientations, although with different current distributions. Computer simulations indicated that a conventional spiral inductor of 205 microns in diameter could be matched by a nanocoil just 70 nanometers wide, with a field strength reaching as much as 1 tesla, about the same as the coils found in typical loudspeakers, about the same field strength as some MRI machines. They found the magnetic field would be strongest in the hollow, nanometer-wide cavity at the spiral's center. [30]

A solenoid made with such a coil behaves as a quantum conductor whose current distribution between the core and exterior varies with applied voltage, resulting in nonlinear inductance. [31]

Related Research Articles

<span class="mw-page-title-main">Boron nitride</span> Refractory compound of boron and nitrogen with formula BN

Boron nitride is a thermally and chemically resistant refractory compound of boron and nitrogen with the chemical formula BN. It exists in various crystalline forms that are isoelectronic to a similarly structured carbon lattice. The hexagonal form corresponding to graphite is the most stable and soft among BN polymorphs, and is therefore used as a lubricant and an additive to cosmetic products. The cubic variety analogous to diamond is called c-BN; it is softer than diamond, but its thermal and chemical stability is superior. The rare wurtzite BN modification is similar to lonsdaleite but slightly softer than the cubic form.

<span class="mw-page-title-main">Carbon nanotube</span> Allotropes of carbon with a cylindrical nanostructure

A carbon nanotube (CNT) is a tube made of carbon with a diameter in the nanometre range (nanoscale). They are one of the allotropes of carbon.

<span class="mw-page-title-main">Allotropes of carbon</span> Materials made only out of carbon

Carbon is capable of forming many allotropes due to its valency. Well-known forms of carbon include diamond and graphite. In recent decades, many more allotropes have been discovered and researched, including ball shapes such as buckminsterfullerene and sheets such as graphene. Larger-scale structures of carbon include nanotubes, nanobuds and nanoribbons. Other unusual forms of carbon exist at very high temperatures or extreme pressures. Around 500 hypothetical 3‑periodic allotropes of carbon are known at the present time, according to the Samara Carbon Allotrope Database (SACADA).

<span class="mw-page-title-main">Graphene</span> Hexagonal lattice made of carbon atoms

Graphene is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds.

<span class="mw-page-title-main">Carbon nanofiber</span>

Carbon nanofibers (CNFs), vapor grown carbon fibers (VGCFs), or vapor grown carbon nanofibers (VGCNFs) are cylindrical nanostructures with graphene layers arranged as stacked cones, cups or plates. Carbon nanofibers with graphene layers wrapped into perfect cylinders are called carbon nanotubes.

<span class="mw-page-title-main">Graphite oxide</span> Compound of carbon, oxygen, and hydrogen

Graphite oxide (GO), formerly called graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers and acids for resolving of extra metals. The maximally oxidized bulk product is a yellow solid with C:O ratio between 2.1 and 2.9, that retains the layer structure of graphite but with a much larger and irregular spacing.

<span class="mw-page-title-main">Rodney S. Ruoff</span> American chemist

Rodney S. "Rod" Ruoff is an American physical chemist and nanoscience researcher. He is one of the world experts on carbon materials including carbon nanostructures such as fullerenes, nanotubes, graphene, diamond, and has had pioneering discoveries on such materials and others. Ruoff received his B.S. in chemistry from the University of Texas at Austin (1981) and his Ph.D. in chemical physics at the University of Illinois-Urbana (1988). After a Fulbright Fellowship at the MPI fuer Stroemungsforschung in Goettingen, Germany (1989) and postdoctoral work at the IBM T. J. Watson Research Center (1990–91), Ruoff became a staff scientist in the Molecular Physics Laboratory at SRI International (1991–1996). He is currently UNIST Distinguished Professor at the Ulsan National Institute of Science and Technology (UNIST), and the director of the Center for Multidimensional Carbon Materials, an Institute for Basic Science Center located at UNIST.

Bilayer graphene is a material consisting of two layers of graphene. One of the first reports of bilayer graphene was in the seminal 2004 Science paper by Geim and colleagues, in which they described devices "which contained just one, two, or three atomic layers"

<span class="mw-page-title-main">Borophene</span> Allotrope of boron

Borophene is a crystalline atomic monolayer of boron, i.e., it is a two-dimensional allotrope of boron and also known as boron sheet. First predicted by theory in the mid-1990s, different borophene structures were experimentally confirmed in 2015.

In materials science, the term single-layer materials or 2D materials refers to crystalline solids consisting of a single layer of atoms. These materials are promising for some applications but remain the focus of research. Single-layer materials derived from single elements generally carry the -ene suffix in their names, e.g. graphene. Single-layer materials that are compounds of two or more elements have -ane or -ide suffixes. 2D materials can generally be categorized as either 2D allotropes of various elements or as compounds.

A two-dimensional semiconductor is a type of natural semiconductor with thicknesses on the atomic scale. Geim and Novoselov et al. initiated the field in 2004 when they reported a new semiconducting material graphene, a flat monolayer of carbon atoms arranged in a 2D honeycomb lattice. A 2D monolayer semiconductor is significant because it exhibits stronger piezoelectric coupling than traditionally employed bulk forms. This coupling could enable applications. One research focus is on designing nanoelectronic components by the use of graphene as electrical conductor, hexagonal boron nitride as electrical insulator, and a transition metal dichalcogenide as semiconductor.

A rapidly increasing list of graphene production techniques have been developed to enable graphene's use in commercial applications.

Graphene-Boron Nitride nanohybrid materials are a class of compounds created from graphene and boron nitride nanosheets. Graphene and boron nitride both contain intrinsic thermally conductive and electrically insulative properties. The combination of these two compounds may be useful to advance the development and understanding of electronics.

<span class="mw-page-title-main">Graphenated carbon nanotube</span>

Graphenated carbon nanotubes are a relatively new hybrid that combines graphitic foliates grown along the sidewalls of multiwalled or bamboo style carbon nanotubes (CNTs). Yu et al. reported on "chemically bonded graphene leaves" growing along the sidewalls of CNTs. Stoner et al. described these structures as "graphenated CNTs" and reported in their use for enhanced supercapacitor performance. Hsu et al. further reported on similar structures formed on carbon fiber paper, also for use in supercapacitor applications. Pham et al. also reported a similar structure, namely "graphene-carbon nanotube hybrids", grown directly onto carbon fiber paper to form an integrated, binder free, high surface area conductive catalyst support for Proton Exchange Membrane Fuel Cells electrode applications with enhanced performance and durability. The foliate density can vary as a function of deposition conditions with their structure ranging from few layers of graphene to thicker, more graphite-like.

<span class="mw-page-title-main">Boron nitride nanosheet</span>

Boron nitride nanosheet is a crystalline form of the hexagonal boron nitride (h-BN), which has a thickness of one atom. Similar in geometry as well as physical and thermal properties to its carbon analog graphene, but has very different chemical and electronic properties – contrary to the black and highly conducting graphene, BN nanosheets are electrical insulators with a band gap of ~5.9 eV, and therefore appear white in color.

AA'-graphite is an allotrope of carbon similar to graphite, but where the layers are positioned differently to each other as compared to the order in graphite.

A graphene helix, similar to the carbon nanotube, is a structure consisting of a two-dimensional sheet of graphene wrapped into a helix. These graphene sheets can have multiple layers, called multi-walled carbon structures, that add to these helices thus increasing their tensile strength but increasing the difficulty of manufacturing. Using van der Waals interactions it can make structures within one another.

Two dimensional hexagonal boron nitride is a material of comparable structure to graphene with potential applications in e.g. photonics., fuel cells and as a substrate for two-dimensional heterostructures. 2D h-BN is isostructural to graphene, but where graphene is conductive, 2D h-BN is a wide-gap insulator.

<span class="mw-page-title-main">Twistronics</span> Study of how the angle between layers of 2-D materials changes their electrical properties

Twistronics is the study of how the angle between layers of two-dimensional materials can change their electrical properties. Materials such as bilayer graphene have been shown to have vastly different electronic behavior, ranging from non-conductive to superconductive, that depends sensitively on the angle between the layers. The term was first introduced by the research group of Efthimios Kaxiras at Harvard University in their theoretical treatment of graphene superlattices.

References

  1. ↑ Kula, Piotr; Pietrasik, Robert; Dybowski, Konrad; Atraszkiewicz, Radomir; Szymanski, Witold; Kolodziejczyk, Lukasz; Niedzielski, Piotr; Nowak, Dorota (2014). "Single and Multilayer Growth of Graphene from the Liquid Phase". Applied Mechanics and Materials. 510: 8–12. doi:10.4028/www.scientific.net/AMM.510.8. S2CID   93345920.
  2. ↑ "Polish scientists find way to make super-strong graphene sheets | Graphene-Info". www.graphene-info.com. Retrieved 2015-07-01.
  3. ↑ Min, Hongki; Sahu, Bhagawan; Banerjee, Sanjay; MacDonald, A. (2007). "Ab initio theory of gate induced gaps in graphene bilayers". Physical Review B. 75 (15): 155115. arXiv: cond-mat/0612236 . Bibcode:2007PhRvB..75o5115M. doi:10.1103/PhysRevB.75.155115. S2CID   119443126.
  4. ↑ Barlas, Yafis; Côté, R.; Lambert, J.; MacDonald, A. H. (2010). "Anomalous Exciton Condensation in Graphene Bilayers". Physical Review Letters. 104 (9): 96802. arXiv: 0909.1502 . Bibcode:2010PhRvL.104i6802B. doi:10.1103/PhysRevLett.104.096802. PMID   20367001. S2CID   33249360.
  5. 1 2 Min, Lola; Hovden, Robert; Huang, Pinshane; Wojcik, Michal; Muller, David A.; Park, Jiwoong (2012). "Twinning and Twisting of Tri- and Bilayer Graphene". Nano Letters. 12 (3): 1609–1615. Bibcode:2012NanoL..12.1609B. doi:10.1021/nl204547v. PMID   22329410.
  6. ↑ Nandwana, Dinkar; Ertekin, Elif (11 March 2015). "Ripples, Strain, and Misfit Dislocations: Structure of Graphene–Boron Nitride Superlattice Interfaces". Nano Letters. 15 (3): 1468–1475. Bibcode:2015NanoL..15.1468N. doi:10.1021/nl505005t. PMID   25647719.
  7. ↑ Xu, Yang; Liu, Yunlong; Chen, Huabin; Lin, Xiao; Lin, Shisheng; Yu, Bin; Luo, Jikui (2012). "Ab initio study of energy-band modulation ingraphene-based two-dimensional layered superlattices". Journal of Materials Chemistry. 22 (45): 23821. doi:10.1039/C2JM35652J.
  8. ↑ Tang, Shujie; Wang, Haomin; Zhang, Yu; Li, Ang; Xie, Hong; Liu, Xiaoyu; Liu, Lianqing; Li, Tianxin; Huang, Fuqiang; Xie, Xiaoming; Jiang, Mianheng (16 September 2013). "Precisely aligned graphene grown on hexagonal boron nitride by catalyst free chemical vapor deposition". Scientific Reports. 3 (1): 2666. arXiv: 1309.0172 . Bibcode:2013NatSR...3E2666T. doi:10.1038/srep02666. PMC   3773621 . PMID   24036628.
  9. ↑ Chen, Lingxiu; He, Li; Wang, Huishan (2017). "Oriented graphene nanoribbons embedded in hexagonal boron nitride trenches". Nature Communications. 8: 14703. arXiv: 1703.03145 . Bibcode:2017NatCo...814703C. doi:10.1038/ncomms14703. PMC   5347129 . PMID   28276532.
  10. ↑ Neto, A Castro; Peres, N. M. R.; Novoselov, K. S.; Geim, A. K.; Geim, A. K. (2009). "The electronic properties of graphene" (PDF). Rev Mod Phys. 81 (1): 109–162. arXiv: 0709.1163 . Bibcode:2009RvMP...81..109C. doi:10.1103/RevModPhys.81.109. hdl:10261/18097. S2CID   5650871. Archived from the original (PDF) on 2010-11-15.
  11. ↑ Li, Xinming; Zhao, Tianshuo; Wang, Kunlin; Yang, Ying; Wei, Jinquan; Kang, Feiyu; Wu, Dehai; Zhu, Hongwei (29 August 2011). "Directly Drawing Self-Assembled, Porous, and Monolithic Graphene Fiber from Chemical Vapor Deposition Grown Graphene Film and Its Electrochemical Properties". Langmuir. 27 (19): 12164–71. doi:10.1021/la202380g. PMID   21875131.
  12. ↑ Li, Xinming; Zhao, Tianshuo; Chen, Qiao; Li, Peixu; Wang, Kunlin; Zhong, Minlin; Wei, Jinquan; Wu, Dehai; Wei, Bingqing; Zhu, Hongwei (3 September 2013). "Flexible all solid-state supercapacitors based on chemical vapor deposition derived graphene fibers". Physical Chemistry Chemical Physics. 15 (41): 17752–7. Bibcode:2013PCCP...1517752L. doi:10.1039/C3CP52908H. PMID   24045695.
  13. ↑ Xin, Guoqing; Yao, Tiankai; Sun, Hongtao; Scott, Spencer Michael; Shao, Dali; Wang, Gongkai; Lian, Jie (4 September 2015). "Highly thermally conductive and mechanically strong graphene fibers". Science. 349 (6252): 1083–1087. Bibcode:2015Sci...349.1083X. doi: 10.1126/science.aaa6502 . PMID   26339027.
  14. ↑ Xu, Zhen; Liu, Yingjun; Zhao, Xiaoli; Li, Peng; Sun, Haiyan; Xu, Yang; Ren, Xibiao; Jin, Chuanhong; Xu, Peng; Wang, Miao; Gao, Chao (2016). "Ultrastiff and Strong Graphene Fibers via Full-Scale Synergetic Defect Engineering". Advanced Materials. 28 (30): 6449–6456. Bibcode:2016AdM....28.6449X. doi:10.1002/adma.201506426. PMID   27184960. S2CID   31988847.
  15. ↑ Harris PJF (2012). "Hollow structures with bilayer graphene walls". Carbon. 50 (9): 3195–3199. doi:10.1016/j.carbon.2011.10.050.
  16. ↑ Harris PJ, Slater TJ, Haigh SJ, Hage FS, Kepaptsoglou DM, Ramasse QM, Brydson R (2014). "Bilayer graphene formed by passage of current through graphite: evidence for a three dimensional structure" (PDF). Nanotechnology. 25 (46): 465601. Bibcode:2014Nanot..25.5601H. doi:10.1088/0957-4484/25/46/465601. PMID   25354780. S2CID   12995375.
  17. ↑ Wang, H.; Sun, K.; Tao, F.; Stacchiola, D. J.; Hu, Y. H. (2013). "3D Honeycomb-Like Structured Graphene and Its High Efficiency as a Counter-Electrode Catalyst for Dye-Sensitized Solar Cells". Angewandte Chemie. 125 (35): 9380–9384. doi:10.1002/ange.201303497. hdl: 2027.42/99684 .
    Wang, Hui; Sun, Kai; Tao, Franklin; Stacchiola, Dario J.; Hu, Yun Hang (2013). "3D graphene could replace expensive platinum in solar cells". Angewandte Chemie. 125 (35): 9380–9384. doi:10.1002/ange.201303497. hdl: 2027.42/99684 . Retrieved 24 August 2013.
  18. ↑ Lalwani, Gaurav; Trinward Kwaczala, Andrea; Kanakia, Shruti; Patel, Sunny C.; Judex, Stefan; Sitharaman, Balaji (2013). "Fabrication and characterization of three-dimensional macroscopic all-carbon scaffolds". Carbon. 53: 90–100. doi:10.1016/j.carbon.2012.10.035. PMC   3578711 . PMID   23436939.
  19. 1 2 Shehzad, Khurram; Xu, Yang; Gao, Chao; Xianfeng, Duan (2016). "Three-dimensional macro-structures of two-dimensional nanomaterials". Chemical Society Reviews. 45 (20): 5541–5588. doi:10.1039/C6CS00218H. PMID   27459895.
  20. ↑ Lalwani, Gaurav; Gopalan, Anu Gopalan; D'Agati, Michael; Srinivas Sankaran, Jeyantt; Judex, Stefan; Qin, Yi-Xian; Sitharaman, Balaji (2015). "Porous three-dimensional carbon nanotube scaffolds for tissue engineering". Journal of Biomedical Materials Research Part A. 103 (10): 3212–3225. doi:10.1002/jbm.a.35449. PMC   4552611 . PMID   25788440.
  21. ↑ R. V. Lapshin (2016). "STM observation of a box-shaped graphene nanostructure appeared after mechanical cleavage of pyrolytic graphite" (PDF). Applied Surface Science. 360: 451–460. arXiv: 1611.04379 . Bibcode:2016ApSS..360..451L. doi:10.1016/j.apsusc.2015.09.222. ISSN   0169-4332. S2CID   119369379. (Russian translation is available).
  22. ↑ Szondy, David (January 9, 2017). "New 3D graphene is ten times as strong as steel". newatlas.com. Retrieved 2017-02-17.
  23. ↑ Zhao, Qin; Gang, Seob Jung; Min, Jeong Kang; Buehler, Markus J. (2017-01-06). "The mechanics and design of a lightweight three-dimensional graphene assembly". Science Advances. 3 (1): e1601536. Bibcode:2017SciA....3E1536Q. doi:10.1126/sciadv.1601536. PMC   5218516 . PMID   28070559.
  24. ↑ Jeffrey, Colin (28 June 2015). "Graphene takes on a new dimension". www.gizmag.com. Retrieved 2015-10-05.
  25. ↑ "How to form 3-D shapes from flat sheets of graphene". www.kurzweilai.net. 30 June 2015. Retrieved 2015-10-05.
  26. ↑ Anthony, Sebastian (10 April 2013). "Graphene aerogel is seven times lighter than air, can balance on a blade of grass - Slideshow | ExtremeTech". ExtremeTech. Retrieved 2015-10-11.
  27. ↑ Cebo, T.; Aria, A. I.; Dolan, J.A.; Weatherup, R. S.; Nakanishi, K.; Kidambi, P. R.; Divitini, G.; Ducati, C.; Steiner, U.; Hofmann, S. (2017). "Chemical vapour deposition of freestanding sub-60 nm graphene gyroids". Applied Physics Letters. 111 (25): 253103. Bibcode:2017ApPhL.111y3103C. doi:10.1063/1.4997774. hdl:1826/13396.
  28. 1 2 3 "Carbon nanotubes as reinforcing bars to strengthen graphene and increase conductivity". KurzweilAI. 9 April 2014. Retrieved 23 April 2014.
  29. ↑ Yan, Z.; Peng, Z.; Casillas, G.; Lin, J.; Xiang, C.; Zhou, H.; Yang, Y.; Ruan, G.; Raji, A. R. O.; Samuel, E. L. G.; Hauge, R. H.; Yacaman, M. J.; Tour, J. M. (2014). "Rebar Graphene". ACS Nano. 8 (5): 5061–8. doi:10.1021/nn501132n. PMC   4046778 . PMID   24694285.
  30. ↑ "Graphene nano-coils discovered to be powerful natural electromagnets | KurzweilAI". www.kurzweilai.net. 16 October 2015. Retrieved 2015-10-18.
  31. ↑ Xu, Fangbo; Yu, Henry; Sadrzadeh, Arta; Yakobson, Boris I. (2015-10-14). "Riemann Surfaces of Carbon as Graphene Nanosolenoids". Nano Letters. 16 (1): 34–9. Bibcode:2016NanoL..16...34X. doi:10.1021/acs.nanolett.5b02430. PMID   26452145.
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