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Tulić S, Waitz T, Čaplovičová M, Habler G, Varga M, Kotlár M, Vretenár V, Romanyuk O, Kromka A, Rezek B, Skákalová V. Covalent Diamond-Graphite Bonding: Mechanism of Catalytic Transformation. ACS NANO 2019; 13:4621-4630. [PMID: 30883098 PMCID: PMC6482437 DOI: 10.1021/acsnano.9b00692] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Aberration-corrected transmission electron microscopy of the atomic structure of diamond-graphite interface after Ni-induced catalytic transformation reveals graphitic planes bound covalently to the diamond in the upright orientation. The covalent attachment, together with a significant volume expansion of graphite transformed from diamond, gives rise to uniaxial stress that is released through plastic deformation. We propose a comprehensive model explaining the Ni-mediated transformation of diamond to graphite and covalent bonding at the interface as well as the mechanism of relaxation of uniaxial stress. We also explain the mechanism of electrical transport through the graphitized surface of diamond. The result may thus provide a foundation for the catalytically driven formation of graphene-diamond nanodevices.
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Affiliation(s)
- Semir Tulić
- Physics
of Nanostructured Materials, Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Thomas Waitz
- Physics
of Nanostructured Materials, Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Mária Čaplovičová
- Slovak
University of Technology, Centre for Nanodiagnostics, Vazovova 5, 812 43 Bratislava, Slovakia
| | - Gerlinde Habler
- Department
of Lithospheric Research, University of
Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Marián Varga
- Institute
of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, Czech Republic
| | - Mário Kotlár
- Slovak
University of Technology, Centre for Nanodiagnostics, Vazovova 5, 812 43 Bratislava, Slovakia
| | - Viliam Vretenár
- Slovak
University of Technology, Centre for Nanodiagnostics, Vazovova 5, 812 43 Bratislava, Slovakia
| | - Oleksandr Romanyuk
- Institute
of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, Czech Republic
| | - Alexander Kromka
- Institute
of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, Czech Republic
| | - Bohuslav Rezek
- Institute
of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, Czech Republic
- Faculty
of Electrical Engineering, Czech Technical
University, Technická
2, Prague 6, Czech Republic
| | - Viera Skákalová
- Physics
of Nanostructured Materials, Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
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Yu Z, Wang X, Bian H, Jiao L, Wu W, Dai H. Enhancement of the heat conduction performance of boron nitride/cellulosic fibre insulating composites. PLoS One 2018; 13:e0200842. [PMID: 30024928 PMCID: PMC6053182 DOI: 10.1371/journal.pone.0200842] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/02/2018] [Indexed: 11/24/2022] Open
Abstract
The continuous development of high electrical equipment towards high power output requires better heat dissipation performance of internal insulation structure. It challenges the traditional paper-based insulating materials, with poor thermal conductivity. Introducing thermally conductive and electrically insulating filler into cellulose-based insulating material can enhance heat conduction performance. This work provided a method to prepare thermally conductive and electrically insulating BN/cellulosic fibre composites. And the thermal conductivity of the composites was remarkably increased via grafting APTES and adding dual-sized fillers. The thermal conductivity of the composite reached 0.682 W/(m•k) that increased by 387% with h-BN loading of 41.08 wt%. Simultaneously, BN fillers improved the insulating properties of the resultant composites. The dielectric constant, breaking strength of and volume resistivity of the composites reached 4.75, 9.2 kV/mm-1 and 4.72×1014 Ω•m, respectively. The resultant insulating material which has better heat conduction property may have a vast potential for future development in electrical equipment.
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Affiliation(s)
- Zhihuai Yu
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China
| | - Xiu Wang
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China
| | - Huiyang Bian
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China
| | - Liang Jiao
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China
| | - Weibing Wu
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China
| | - Hongqi Dai
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China
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Jaworski Z, Zakrzewska B, Pianko-Oprych P. On thermodynamic equilibrium of carbon deposition from gaseous C-H-O mixtures: updating for nanotubes. REV CHEM ENG 2017. [DOI: 10.1515/revce-2016-0022] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractExtensive literature information on experimental thermodynamic data and theoretical analysis for depositing carbon in various crystallographic forms is examined, and a new three-phase diagram for carbon is proposed. The published methods of quantitative description of gas-solid carbon equilibrium conditions are critically evaluated for filamentous carbon. The standard chemical potential values are accepted only for purified single-walled and multi-walled carbon nanotubes (CNT). Series of C-H-O ternary diagrams are constructed with plots of boundary lines for carbon deposition either as graphite or nanotubes. The lines are computed for nine temperature levels from 200°C to 1000°C and for the total pressure of 1 bar and 10 bar. The diagram for graphite and 1 bar fully conforms to that in (Sasaki K, Teraoka Y. Equilibria in fuel cell gases II. The C-H-O ternary diagrams. J Electrochem Soc 2003b, 150: A885–A888). Allowing for CNTs in carbon deposition leads to significant lowering of the critical carbon content in the reformates in temperatures from 500°C upward with maximum shifting up the deposition boundary O/C values by about 17% and 28%, respectively, at 1 and 10 bar.
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