Strength of carbon nanotubes depends on their chemical structures

Takakura, Akira; Beppu, Ko; Nishihara, Taishi; Fukui, Akihito; Kozeki, Takahiro; Namazu, Takahiro; Miyauchi, Yuhei; Itami, Kenichiro

doi:10.1038/s41467-019-10959-7

Cited by 181 publications

(97 citation statements)

References 37 publications

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“…The history of nanotubes [1,2] and fullerenes [3] spans several decades; the most important stages in understanding of their nature and properties are well represented in recent reviews and books [4][5][6][7][8][9][10]. The main directions of practical application of such nanoobjects are connected with creation of new materials [4,[7][8][9][10][11][12][13][14], applications in pharmacy and medicine [15][16][17][18][19][20][21][22][23][24] and wastewater treatment [25]. These possibilities resulted mainly from the formation of endohedral complexes of fullerenes and nanotubes; the first example, synthesis of lanthanum complexes of C 60 , was described in [26].…”

Section: Introductionmentioning

confidence: 99%

Stereochemistry of Simple Molecules inside Nanotubes and Fullerenes: Unusual Behavior of Usual Systems

Кузнецов

2020

Molecules

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Over the past three decades, carbon nanotubes and fullerenes have become remarkable objects for starting the implementation of new models and technologies in different branches of science. To a great extent, this is defined by the unique electronic and spatial properties of nanocavities due to the ramified π-electron systems. This provides an opportunity for the formation of endohedral complexes containing non-covalently bonded atoms or molecules inside fullerenes and nanotubes. The guest species are exposed to the force field of the nanocavity, which can be described as a combination of electronic and steric requirements. Its action significantly changes conformational properties of even relatively simple molecules, including ethane and its analogs, as well as compounds with C−O, C−S, B−B, B−O, B−N, N−N, Al−Al, Si−Si and Ge−Ge bonds. Besides that, the cavity of the host molecule dramatically alters the stereochemical characteristics of cyclic and heterocyclic systems, affects the energy of pyramidal nitrogen inversion in amines, changes the relative stability of cis and trans isomers and, in the case of chiral nanotubes, strongly influences the properties of R- and S-enantiomers. The present review aims at primary compilation of such unusual stereochemical effects and initial evaluation of the nature of the force field inside nanotubes and fullerenes.

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Section: Introductionmentioning

confidence: 99%

Stereochemistry of Simple Molecules inside Nanotubes and Fullerenes: Unusual Behavior of Usual Systems

Кузнецов

2020

Molecules

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“…Studies concerning carbon nanotubes (CNT) have surged since the groundbreaking work reported by Iijima 19 . The tensile strength of individual CNT can reach as high as 66 GPa 20 which is two orders of magnitude higher than that of steel. In addition, the electrical conductivity of CNTs ranges from 8 × 10 −6 to 20 × 10 −6 Ω m as per Dai et al 21 and the thermal conductivity of CNT falls in a range of 2000 ~ 6000 W/mK as per Han and Fina 22 .…”

Section: Introductionmentioning

confidence: 99%

Microinjection molding of polyoxymethylene/multiwalled carbon nanotubes composites with different matrix viscosities

Zhou

Xue

Mei

et al. 2020

J of Applied Polymer Sci

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This study features the effect of matrix viscosity on the properties of carbon nanotubes reinforced polyoxymethylene (POM/CNT) microparts, which were obtained via melt blending and subsequent microinjection molding (μIM) processes, under a defined set of processing conditions. Results of compression molding and μIM were compared to assess the influence of processing methods (i.e., thermomechanical history) on the electrical and thermal conductivities, melting and crystallization behavior as well as the thermal degradation resistance of POM/CNT composites. Filler orientation in POM/CNT microparts was evaluated using Raman spectral analysis. The electrical conductivity measurements revealed that matrix viscosity plays a significant role in determining the distribution of CNT. Also, the extreme shearing conditions that prevail in μIM are unfavorable for the construction of random conductive pathways within the micromoldings, as corroborated by transmission electron microscopy. Although the thermal degradation resistance of both POM/CNT composites and corresponding microparts deteriorated with increasing filler concentration, samples prepared with higher matrix viscosity showed higher thermal stability when compared with lower matrix viscosity counterparts. This study provides valuable insights into fabricating multifunctional microparts for potential industrial applications in replacement of metallic components for precision electronic instruments.

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“…As a consequence, SPCs can exhibit exotic adsorption properties with application in the area of gas storage, separation and sensing. [17][18][19][20][21][22][23][24][25][26] Despite extensive knowledge about the mechanical properties of polymers and metals typically used in the construction of macroscopic metamaterials and the advancing understanding of the mechanical properties of nanoscopic materials such as poly(ethylene glycol), 27 DNA, 28 or carbon nanotubes, 29 little is known regarding the mechanical behaviour of individual small molecules and their influence on the elastic and inelastic response of molecular crystalline frameworks. 30,31 In 2016, we discovered the counterintuitive adsorption phenomenon termed negative gas adsorption (NGA) in the flexible MOF named DUT-49 (Dresden University of Technology Nr.…”

Section: Introductionmentioning

confidence: 99%

Engineering Micromechanics of Soft Porous Crystals for Negative Gas Adsorption

Krause

Evans²,

Bon³

et al. 2020

Preprint

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Framework materials at the molecular level, such as metal-organic frameworks (MOF), were recently found to exhibit exotic and counterintuitive micromechanical properties. Stimulated by host-guest interactions, these so-called soft porous crystals can display counterintuitive adsorption phenomena such as negative gas adsorption (NGA). NGA materials are bistable frameworks where the occurrence of a metastable overloaded state leads to pressure amplification upon a sudden framework contraction. How can we control activation barriers and energetics via functionalization of the molecular building blocks that dictate the frameworks’ 30 mechanical response? In this work we tune the elastic and inelastic properties of building blocks at the 31 molecular level and analyze the mechanical response of the resulting frameworks. From a set of 11 frameworks, we demonstrate that widening of the backbone increases elasticity, while elongation of the building blocks results in a decrease in critical yield stress of buckling. We further functionalize the backbone by incorporation of sp3 hybridized carbon atoms to soften the molecular building blocks, or stiffen them with sp2 and sp carbons. Computational modeling shows how these modifications of the building blocks tune the 36 activation barriers within the energy landscape of the guest-free bistable frameworks. Only frameworks with free energy barriers in the range of 800 to 1100 kJ mol–1 37 per unit cell, and moderate yield stress of 0.6 to 38 1.2 nN for single ligand buckling, exhibit adsorption-induced contraction and negative gas adsorption. Advanced experimental in situ methodologies give detailed insights into the structural transitions and the adsorption behavior. The new framework DUT-160 shows the highest magnitude of NGA ever observed for nitrogen adsorption at 77 K. Our computational and experimental analysis of the energetics and mechanical response functions of porous frameworks is an important step towards tuning activation barriers in dynamic framework materials and provides critical design principles for molecular building blocks leading to pressure amplifying materials<br>

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Strength of carbon nanotubes depends on their chemical structures

Cited by 181 publications

References 37 publications

Stereochemistry of Simple Molecules inside Nanotubes and Fullerenes: Unusual Behavior of Usual Systems

Stereochemistry of Simple Molecules inside Nanotubes and Fullerenes: Unusual Behavior of Usual Systems

Microinjection molding of polyoxymethylene/multiwalled carbon nanotubes composites with different matrix viscosities

Engineering Micromechanics of Soft Porous Crystals for Negative Gas Adsorption

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