WO2018099774A1 - Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polytungstate - Google Patents

Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polytungstate Download PDF

Info

Publication number
WO2018099774A1
WO2018099774A1 PCT/EP2017/079989 EP2017079989W WO2018099774A1 WO 2018099774 A1 WO2018099774 A1 WO 2018099774A1 EP 2017079989 W EP2017079989 W EP 2017079989W WO 2018099774 A1 WO2018099774 A1 WO 2018099774A1
Authority
WO
WIPO (PCT)
Prior art keywords
carbon nanotubes
walled carbon
semi
conducting
centrifugation
Prior art date
Application number
PCT/EP2017/079989
Other languages
English (en)
Inventor
Zeljko Tomovic
Wieland REIS
Jules MIKHAEL
Original Assignee
Basf Se
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Basf Se filed Critical Basf Se
Publication of WO2018099774A1 publication Critical patent/WO2018099774A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/168—After-treatment
    • C01B32/172—Sorting
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/311—Purifying organic semiconductor materials
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/20—Carbon compounds, e.g. carbon nanotubes or fullerenes
    • H10K85/221—Carbon nanotubes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/20—Nanotubes characterized by their properties
    • C01B2202/22—Electronic properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/549—Organic PV cells

Definitions

  • the present invention relates to a method for separating semi-conducting and metallic single- walled carbon nanotubes from each other and, if present, from other carbonaceous material, or for separating semi-conducting single-walled carbon nanotubes from other carbonaceous material via a centrifugation step performed at a temperature of > 25°C using a solution of a poly- tungstate; to semi-conducting single-walled carbon nanotubes obtainable by this method; and to the use of these semi-conducting single-walled carbon nanotubes e.g. in electronic devices, optical devices, optoelectronic devices, energy storage devices and the like.
  • Carbon nanotubes are allotropes of carbon with a cylindrical nanostructure and are members of the fullerene structural family. Their name is derived from their long, hollow structure with the walls formed by one-atom-thick sheets of carbon, i.e. by graphene. These sheets are rolled at specific and discrete ("chiral") angles, and the combination of the rolling angle and radius decides the nanotube properties; for example, whether the individual nanotube shell shows a metal or semiconductor behavior.
  • Carbon nanotubes are generally categorized as sin- gle-walled carbon nanotubes (SWCNTs; often just SWNTs) and multi-walled carbon nanotubes (MWCNTs; often just MWNTs).
  • the structure of an SWNT can be conceptualized by wrapping a one-atom-thick layer of graphene into a seamless cylinder.
  • SWNTs are available in a large number of different chiralities due to various combinations of diameter and wrapping angle.
  • the nanotube chirality defines both its electronic and optical properties, and hence is a critical parameter when incorporating nanotubes into device applications. For instance, roughly two thirds of SWNT chiralities are semiconducting, while the rest are of metallic nature.
  • the first- order peaks in optical absorbance for metallic SWNTs can vary widely from about 400 nm to 800 nm as SWNT diameter is increased from 0.7 nm to 1 .8 nm.
  • SWNTs typically consist of a mixture of semiconducting and metallic nanotubes with varying diameters.
  • Methods for the synthesis of CNTs are arc discharge, laser ablation, high-pressure carbon monoxide dis- proportionation (also termed high pressure CO conversion; HiPCO), plasma torch, aerosol synthesis, chemical vapor deposition (CVD) and combinations thereof.
  • the buoyant densities of SWNTs in aqueous solution subtly depend on factors such as the mass and volume of the SWCNT itself, its surface functionalization and charge, coverage with surface-active compounds and electrostatically bound hydration layers. The differences in the buoyant densities result into different positions of the SWNTs within a density gradient medium when they are subjected to high centripetal forces.
  • SWNTs sin-conducting and metallic
  • standard surfactants such as sodium cholate or sodium dodecyl sulfate
  • just one type, mostly the semi-conducting SWNT is functionalized with specific additives.
  • This (partial) functionalization enhances the difference in the densities of the various SWNT types.
  • the (partly) functionalized SWNTs are then subjected to a density gradient ultracentrifugation (DGU). Under high gravitational forces the nanomaterials are driven by density differences to positions where their buoyant density is equal to that of the surrounding fluid (isopycnic point).
  • DGU density gradient ultracentrifugation
  • Density gradient media so far used for SWCNT separation are aqueous solutions of sugar(-like) molecules, such as sucrose, polysucrose, Nycodenz® (5-(N-2,3-dihydroxy- propylacetamido)-2,4,6-tri-iodo-N-N'-bis(2,3-dihydroxypropyl)isophthalamide; iohexol) or iodixa- nol (5- ⁇ N-[3-(N- ⁇ 3,5-bis[(2,3-dihydroxypropyl)carbamoyl]-2,4,6-triiodophenyl ⁇ -acetamido)-2-hy- droxypropyl]acetamido ⁇ -1 -N,3-N-bis(2,3-dihydroxypropyl)-2,4,6-triiodobenzene-1 ,3-dicarbox- amide).
  • Another density gradient medium used for SWCNT separation is Percoll® (
  • the density medium is an aqueous solution of iodixanol further containing the surfactant sodium cholate. This surfactant is also used for dispersing/functionalizing the nanotubes.
  • A.A. Green and M.C. Hersam, Advanced Materials 201 1 , 23, 2185-2190 produce nearly single- chirality single-walled CNTs via orthogonal iterative DGU using sodium dodecyl sulfate in combination with sodium cholate as surfactants and iodixanol as density medium.
  • WO 2016/024196 describes the separation of CNTs via density gradient centrifugation by using a semiconducting polymer as surfactants. It is disclosed that the centrifugation is preferably performed in the temperature range of 10 to 20°C.
  • the disadvantage of the separation methods of the prior art is the laborious, time-consuming preparation of the density gradients.
  • semiconducting polymer when used as surfactant expensive catalysts are needed for the synthesis of such polymers, and toxic aromatic or heteroaromatic solvents are used.
  • the separation step can be done only at very low concentration of CNTs such as 0.01 wt.-%.
  • satisfactory separations are only obtained after protracted centrifugation times and require high rotational speeds (e.g. 55,000 rpm or 300,000 x g).
  • the resulting bands containing the enriched SWNT forms are often small and diffuse and thus very difficult to separate. This impedes separation on a higher scale.
  • the viscosity sharply increases with increasing concentration of the density gradient medium.
  • WO 2016/046153 discloses a successful separation of CNTs using room-temperature centrifugation with moderate rotational speeds of 10,000 x g.
  • the term "room-temperature” is generally accepted to refer to an actual temperature between 18 and 25 °C. It is disclosed that the separation could be done by using polyarylether as surface-active compound in a solution of poly- tungstate. Therefore, WO 2016/046153 discloses a process suitable for large-scale technologi- cal processes. Since electronic applications require predictable and uniform performance, strategies are sought for effective post synthesis separation of SWCNTs.
  • SWCNTs have to be in the highest possible semiconducting purity to compete with existing semiconductor technology and thus, getting highest possible semiconducting purity is an ongo- ing task in this technical field.
  • the object of the present invention was to provide a method for separating semi-conducting single-walled carbon nanotubes from other carbonaceous material, in particular from metallic single-walled carbon nanotubes, which is simpler, less tedious and less energy- and/or time-con- suming than the prior art methods, especially the prior art using high rotational speeds or DGU.
  • the process should be suitable for large-scale technological processes.
  • the process should yield the highest purity semi-conducting single-walled carbon nanotubes.
  • the performance of the centrifugation step whereas the centrifugation is performed at a temperature of > 25°C and using a solution of polytungstates, especially SPT, as a separation medium, proved to be a useful separation method which results in high purity semi-conducting single-walled carbon nanotubes.
  • the time period of centrifugation could be reduced in comparison to room-temperature centrifugation.
  • the invention thus relates to a method for separating semi-conducting single-walled carbon nanotubes from metallic single-walled carbon nanotubes and, if present, from other carbonaceous material, or for separating semi-conducting single-walled carbon nanotubes from other carbonaceous material, whereas method comprises bringing a composition containing semiconducting and metallic single-walled carbon nanotubes and optionally other carbonaceous material, or a composition containing semi-conducting carbon nanotubes and other carbonaceous material, into contact with at least one surface-active compound and with a solution of a poly- tungstate, and subjecting the obtained composition to a centrifugation step, whereas the centrifugation is performed at a temperature of > 25°C.
  • the obtained nanotubes are also separated from metal oxide impurities and catalyst particles (e.g. Fe, Co, Ni, etc.) used for synthesis of CNTs, which remain after production of the CNTs.
  • the invention thus relates in one aspect to a method for separating semi-conducting and metal- lie single-walled carbon nanotubes from each other and, optionally and if present, from other carbonaceous material, metal oxide impurities and/or catalyst particles, or for separating semi- conducting single-walled carbon nanotubes from other carbonaceous material, metal oxide impurities and/or catalyst particles, whereas method comprises bringing a composition containing semi-conducting and metallic single-walled carbon nanotubes and optionally other carbonaceous material, metal oxide impurities and/or catalyst particles, or a composition containing semi-conducting carbon nanotubes and other carbonaceous material, metal oxide impurities and/or catalyst particles, into contact with at least one surface-active compound and with a solution of a polytungstate, and subjecting the obtained composition to a centrifugation step, whereas the centrifugation is performed at a temperature of > 25°C.
  • the invention thus relates to a method for separating semi-conducting and metallic single-walled carbon nanotubes from each other and, optionally and if present, from other carbonaceous material, whereas method comprises bringing a composition containing semi-conducting and metallic single-walled carbon nanotubes and optionally other carbonaceous material into contact with at least one surface-active compound and with a solution of a polytungstate, and subjecting the obtained composition to a centrifugation step, whereas the centrifugation is performed at a temperature of > 25°C.
  • the invention relates to a method for separating semi-conducting single- walled carbon nanotubes from other carbonaceous material, whereas method comprises bring- ing a composition containing semi-conducting carbon nanotubes and other carbonaceous material, in particular metallic single-walled carbon nanotubes, into contact with at least one surface- active compound and with a solution of a polytungstate, and subjecting the obtained composition to a centrifugation step, whereas the centrifugation is performed at a temperature of > 25°C.
  • the invention thus relates to a method for separating semi-conducting single- walled carbon nanotubes from metal oxide impurities and/or catalyst particles, whereas method comprises bringing a composition containing semi-conducting single-walled carbon nanotubes and metal oxide impurities and/or catalyst particles into contact with at least one surface-active compound and with a solution of a polytungstate, and subjecting the obtained composition to a centrifugation step, whereas the centrifugation is performed at a temperature of > 25°C.
  • the invention thus also relates to a method for obtaining semi-conducting single-walled carbon nanotubes, whereas method comprises bringing a composition containing semi-conducting single-walled carbon nanotubes and undesired carbonaceous material into contact with at least one surface-active compound and then with a solution of a polytungstate, and subjecting the obtained composition to a centrifugation step, whereas the centrifugation is performed at a temperature of > 25°C.
  • the method of the invention using a polytungstate as a separation medium can be used for obtaining either preferentially semi-conducting single-walled carbon nanotubes or both semi-conducting and metallic single-walled carbon nanotubes. In a preferred embodiment, however, the method of the invention serves for obtaining semi-conducting single-walled carbon nanotubes.
  • the organic moieties mentioned in the below definitions of the variables are - like the term halogen - collective terms for individual listings of the individual group members.
  • the prefix C n -C m indicates in each case the possible number of carbon atoms in the group.
  • the term halogen denotes in each case fluorine, bromine, chlorine or iodine, in particular fluorine, chlorine or bromine.
  • alkyl as used herein and in the alkyl moieties of alkoxy, alkylthio, alkylsulfonyl, alkyl- carbonyl, alkoxycarbonyl etc. refers to saturated straight-chain or branched hydrocarbon radi- cals having 1 to 4 (“Ci-C 4 -alkyl") or 1 to 10 (“Ci-Cio-alkyl") or 1 to 20 (“Ci-C 20 -alkyl”) or 10 to 20 (“Cio-C 2 o-alkyl") or 2 (“C 2 -alkyl") or 2 to 3 (“C 2 -C 3 -alkyl”) or 2 to 5 (“C 2 -C 3 -alkyl”) carbon atoms.
  • Ci-C 4 -Alkyl is methyl, ethyl, n-propyl, isopropyl, n-butyl, 1 -methylpropyl (sec-butyl), 2-methylpro- pyl (isobutyl) or 1 ,1 -dimethylethyl (tert-butyl).
  • Ci-Cio-Alkyl is additionally also, for example, pen- tyl, 1 -methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1 -ethylpropyl, 1 ,1 -dime- thylpropyl, 1 ,2-dimethylpropyl, hexyl, 1 -methylpentyl, 2-methylpentyl, 3-methylpentyl, 4- methylpentyl, 1 ,1 -dimethylbutyl, 1 ,2-dimethylbutyl, 1 ,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-di- methylbutyl, 3,3-dimethylbutyl, 1 -ethylbutyl, 2-ethylbutyl, 1 ,1 ,2-trimethylpropyl, 1 ,2,2-trime- thylpropyl, 1 -ethyl-1
  • Ci-C 2 o-Alkyl is additionally also, for example, undecyl, do- decyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl and positional isomers thereof.
  • Cio-C 2 o-alkyl examples include decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl and positional isomers thereof.
  • C 2 -Alkyl is ethyl.
  • C 2 -C3-Alkyl is ethyl, n-propyl or isopropyl.
  • C 2 -Cs-Alkyl is additionally also, for example, n-butyl, 1 -methylpropyl (sec-butyl), 2-methylpropyl (isobutyl), 1 ,1 -di- methylethyl (tert-butyl), pentyl, 1 -methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1 -ethylpropyl, 1 ,1 -dimethylpropyl or 1 ,2-dimethylpropyl.
  • haloalkyl refers to straight-chain or branched alkyl groups having 1 to 4 (“Ci-C 4 -haloalkyl”) carbon atoms (as mentioned above), where some or all of the hydrogen atoms in these groups are replaced by halogen atoms as mentioned above.
  • Examples are chloromethyl, bromomethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluo- romethyl, chlorofluoromethyl, dichlorofluoromethyl, chlorodifluoromethyl, 1 -chloroethyl, 1 -bromo- ethyl, 1 -fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl, 2- chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2-trichloroethyl, pentafluoroethyl, 1 - fluoropropyl, 2-fluoropropyl, 3-fluoropropyl, 1 ,1 -difluoropropyl, 2,2-difluoropropy
  • Ci-C4-Hydroxyalkyl is a Ci-C4-alkyl group as defined above wherein one of the hydrogen atoms is replaced by an OH group. Examples are hydroxymethyl, 1 -hydroxyethyl, 2-hydroxyethyl, 1 - hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1 -hydroxy-1 -methylethyl, 2-hydroxy-1 -meth- ylethyl, 1 -hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl and the like.
  • Ci-C4-alkoxy is a Ci-C4-alkyl group, as defined above, attached via an oxygen atom.
  • Ci-Cio-alkoxy is a Ci-Cio-alkyl group, as defined above, attached via an oxygen atom.
  • Ci-C4-Alkoxy is methoxy, ethoxy, n-propoxy, 1 -methylethoxy (isopropoxy), butoxy, 1 -methylpropoxy (sec-butoxy), 2-methylpropoxy (isobutoxy) or 1 ,1 -dimethylethoxy (tert-butoxy).
  • Ci-Cio-Alkoxy is additionally, for example, pentoxy, 1 -methylbutoxy, 2-methylbutoxy, 3-methyl- butoxy, 1 ,1 -dimethylpropoxy, 1 ,2-dimethylpropoxy, 2,2-dimethylpropoxy, 1 -ethylpropoxy, hexoxy, 1 -methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1 ,1 -dimethylbut- oxy, 1 ,2-dimethylbutoxy, 1 ,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dime- thylbutoxy, 1 -ethylbutoxy, 2-ethylbutoxy, 1 ,1 ,2-trimethylpropoxy, 1 ,2,2-trimethylpropoxy, 1 -ethyl-
  • Ci-C4-haloalkoxy is a Ci-C4-haloalkyl group, as defined above, attached via an oxygen atom.
  • Ci-C 4 -Haloalkoxy is, for example, OCH 2 F, OCHF 2 , OCF 3 , OCH 2 CI, OCHC , OCCI 3 , chlorofluoromethoxy, dichlorofluoromethoxy, chlorodifluoromethoxy, 2-fluoroethoxy, 2-chloroeth- oxy, 2-bromoethoxy, 2-iodoethoxy, 2,2-difluoroethoxy, 2,2,2-trifluoroethoxy, 2-chloro-2-fluoro- ethoxy, 2-chloro-2,2-difluoroethoxy, 2,2-dichloro-2-fluoroethoxy, 2,2,2-trichloroethoxy, OC2F5,
  • Ci-C4-alkylthio is a Ci-C4-alkyl group, as defined above, attached via a sulfur atom.
  • Ci-C4-Alkylthio is methylthio, ethylthio, n-propylthio, 1 -methylethylthio (isopropylthio), n-bu- tylthio, 1 -methylpropylthio (sec-butylthio), 2-methylpropylthio (isobutylthio) or 1 ,1 -dimethylethyl- thio (tert-butylthio).
  • Ci-C4-haloalkylthio is a Ci-C4-haloalkyl group, as defined above, attached via a sulfur atom.
  • Ci-C 4 -Haloalkylthio is, for example, SCH 2 F, SCHF 2 , SCF 3 , SCH 2 CI, SCHC , SCCI 3 , chlorofluoromethylthio, dichlorofluoromethylthio, chlorodifluoromethylthio, 2-fluoroethylthio, 2- chloroethylthio, 2-bromoethylthio, 2-iodoethylthio, 2,2-difluoroethylthio, 2,2,2-trifluoroethylthio, 2- chloro-2-fluoroethylthio, 2-chloro-2,2-difluoroethylthio, 2,2-dichloro-2-fluoroethylthio, 2,2,2-tri- chlor
  • Ci-C4-alkylsulfonyl is a Ci-C4-alkyl group, as defined above, attached via a sulfonyl [S(0)2] group.
  • Ci-C4-Alkylsulfonyl is methylsulfonyl , ethylsulfonyl, n-propylsulfonyl, 1 -meth- ylethylsulfonyl (isopropylsulfonyl), n-butylsulfonyl, 1 -methylpropylsulfonyl (sec-butylsulfonyl), 2- methylpropylsulfonyl (isobutylsulfonyl) or 1 ,1 -dimethylethylsulfonyl (tert-butylsulfonyl).
  • Ci-C4-haloalkylsulfonyl is a Ci-C4-haloalkyl group, as defined above, attached via a sulfonyl [S(0) 2 ] group.
  • Ci-C 4 -Haloalkylsulfonyl is, for example, S(0) 2 CH 2 F, S(0) 2 CHF 2 ,
  • S(0) 2 CF 3 S(0) 2 CH 2 CI, S(0) 2 CHCI 2 , S(0) 2 CCI 3 , chlorofluoromethylsulfonyl, dichlorofluorome- thylsulfonyl, chlorodifluoromethylsulfonyl, 2-fluoroethylsulfonyl, 2-chloroethylsulfonyl, 2-bromo- ethylsulfonyl, 2-iodoethylsulfonyl, 2,2-difluoroethylsulfonyl, 2,2,2-trifluoroethylsulfonyl, 2-chloro- 2-fluoroethylsulfonyl, 2-chloro-2,2-difluoroethylsulfonyl, 2,2-dichloro-2-fluoroethylsulfonyl, 2,2,2-trichloroethylsulf
  • Carboxyl is -C(0)OH.
  • Ci-C4-alkylamino is a group -N(H)Ci-C4-alkyl. Examples are methylamino, ethyla- mino, propylamino, isopropylamino, butylamino and the like.
  • di-(Ci-C4-alkyl)amino is a group -N(Ci-C4-alkyl)2. Examples are dimethylamino, di- ethylamino, ethylmethylamino, dipropylamino, diisopropylamino, methylpropylamino, methyli- sopropylamino, ethylpropylamino, ethylisopropylamino, dibutylamino and the like.
  • Ci-C4-alkylaminocarbonyl is a group -C(0)-N(H)Ci-C4-alkyl. Examples are methyla- minocarbonyl, ethylaminocarbonyl, propylaminocarbonyl, isopropylaminocarbonyl, butyla- minocarbonyl and the like.
  • di-(Ci-C4-alkyl)aminocarbonyl is a group -C(0)-N(Ci-C4-alkyl)2.
  • dime- thylaminocarbonyl diethylaminocarbonyl, ethylmethylaminocarbonyl, dipropylaminocarbonyl, diisopropylaminocarbonyl, methylpropylaminocarbonyl, methylisopropylaminocarbonyl, ethylpropylaminocarbonyl, ethylisopropylaminocarbonyl, dibutylaminocarbonyl and the like.
  • C2-C5-Alkylene is a linear or branched divalent alkyl radical having 2, 3, 4 or 5 carbon atoms. Examples are -CH 2 CH 2 -, -CH(CH 3 )-, -CH 2 CH 2 CH 2 -, -CH(CH 3 )CH 2 -,
  • C2-C6-Alkylene is a linear or branched divalent alkyl radical having 2, 3, 4, 5 or 6 carbon atoms. Examples, in addition to the radicals stated above for C2-Cs-alkylene, are
  • Ci-Cio-Alkylene is a linear or branched divalent alkyl radical having 1 , 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms.
  • Examples, in addition to the radicals stated above for C2-C6-alkylene, are meth- ylene (-CH2-), -(CH2) n - with n 7, 8, 9 or 10, and position isomers thereof.
  • Aryl is an aromatic carbocyclic ring. Examples are phenyl, naphthyl, phenanthrenyl and anthra- cenyl.
  • Aryl-Ci-C4-alkyl is an aryl ring as defined above attached via a Ci-C4-alkyl group as defined above. Examples are benzyl, 1 -phenylethyl and phenethyl.
  • the composition containing semi-conducting single-walled carbon nanotubes generally contains at least one of the following carbonaceous materials: metallic single-walled carbon nanotubes, graphene, fullerenes, MWNTs, graphite, carbon black, amorphous carbon. Depending on the origin of the carbon source, the composition might also contain catalyst residues from the CNT production process which, of course, are to be unhitched as well. In particular, the composition containing semi-conducting single-walled carbon nanotubes also contains metallic single-walled carbon nanotubes, and optionally also graphene, fullerenes, MWNTs, graphite, carbon black and/or amorphous carbon.
  • the composition of course contains both semi-conducting and metallic single-walled carbon nanotubes and optionally also other carbonaceous materials such as graphene, fullerenes, MWNTs, graphite, carbon black and/or amorphous carbon, and possibly also catalyst residues from the CNT production process.
  • the composition containing semi-conducting and metallic single-walled carbon nanotubes can be obtained by any of the known methods for producing CNTs, such as arc discharge, laser ablation, high-pressure carbon monoxide disproportionation (also termed high pressure CO con- version; HiPCO), plasma torch, aerosol synthesis, chemical vapor deposition (CVD) and combinations thereof. Most of these processes take place in a vacuum or with process gases. CVD growth of CNTs can occur in vacuum or at atmospheric pressure. Specifically, the composition is obtained by HiPCO. CNTs can be produced in the presence of catalysts, most commonly nickel, cobalt, iron or a combination thereof. The catalyst is generally provided in the form of metal nanoparticles. The catalyst may also be supported on an inert catalyst carrier, such as alumina or silica.
  • the obtained CNTs differ in varies properties depending on the synthesis method; for example the diameters may range from 1 .0 to 1.5 nm (synthesized by plasma torch), 0.7 to 1.2 nm (syn- thesized by HiPco) and 1 .2 to 1.8 (synthesized by arc discharge).
  • Surface-active compounds are for example anionic, cationic, nonionic and amphoteric surfactants, block polymers, polyelectrolytes, and mixtures thereof.
  • surfactants are listed in McCutcheon's, Vol.1 : Emulsifiers & Detergents, McCutcheon's Directories, Glen Rock, USA, 2008 (International Ed. or North American Ed.).
  • Suitable anionic surfactants are for example alkali, alkaline earth or ammonium salts of sulfonates, sulfates, phosphates, carboxylates, and mixtures thereof.
  • sulfonates are alkylarylsulfonates, diphenylsulfonates, alpha-olefin sulfonates, lignine sulfonates, sulfonates of fatty acids and oils, sulfonates of ethoxylated alkylphenols, sulfonates of alkoxylated arylphe- nols, sulfonates of condensed naphthalenes, sulfonates of dodecyl- and tridecylbenzenes, sulfonates of naphthalenes and alkylnaphthalenes, sulfosuccinates or sulfosuccinamates.
  • Examples of sulfates are sulfates of fatty acids and oils, of ethoxylated alkylphenols, of alcohols, of ethoxylated alcohols, or of fatty acid esters.
  • Examples of phosphates are phosphate esters.
  • Examples of carboxylates are alkyl carboxylates, and carboxylated alcohol or alkylphenol ethox- ylates.
  • nonionic surfactants are alkoxylates, N-subsituted fatty acid amides, amine oxides, esters, sugar-based surfactants, polymeric surfactants, and mixtures thereof.
  • alkoxylates are compounds such as alcohols, alkylphenols, amines, amides, arylphenols, fatty acids or fatty acid esters which have been alkoxylated with 1 to 50 equivalents.
  • Ethylene oxide and/or propylene oxide may be employed for the alkoxylation, preferably ethylene oxide.
  • N-substituted fatty acid amides are fatty acid glucamides or fatty acid alkanolamides.
  • esters are fatty acid esters, glycerol esters or monoglycerides.
  • sugar- based surfactants are sorbitans, ethoxylated sorbitans, sucrose and glucose esters or alkylpoly- glucosides.
  • polymeric surfactants are home- or copolymers of vinylpyrrolidone, vi- nylalcohols, or vinylacetate.
  • cationic surfactants are quaternary surfactants, for example quaternary ammonium compounds with one or two hydrophobic groups, or salts of long-chain primary amines.
  • Suitable amphoteric surfactants are alkylbetains and imidazolines.
  • Suitable block polymers are block polymers of the A-B or A-B-A type comprising blocks of polyethylene oxide and polypropylene oxide, or of the A-B-C type comprising alkanol, polyethylene oxide and polypropylene oxide.
  • Suitable polyelectrolytes are polyacids or polybases. Examples of polyacids are alkali salts of polyacrylic acid or polyacid comb polymers. Examples of polybases are polyvinylamines or polyethyleneamines.
  • the surface-active compound to be used in the present invention is preferably selected from polyarylethers, polyarylsulfonates, poly(alkyleneoxide) blockcopolymers, condensation products of at least one arylsulfonic acid, at least one aldehyde and optionally at least one further com- pound different from arylsulfonic acids and aldehydes which is capable of undergoing condensation with the arylsulfonic acid(s) and/or the aldehyde(s); and salts thereof.
  • alkylene oxides such as ethylene oxide (EO), propylene oxide (PO), tetrahydrofuran or pentylene oxide.
  • EO ethylene oxide
  • PO propylene oxide
  • tetrahydrofuran pentylene oxide
  • aryl groups carrying one or more hydroxyl groups which are reacted with EO, PO, tetrahydrofuran, pentylene oxide and/or the like, or with other com- pounds suitable for ether formation, such as hydroxyalkyl halides, tosylates or triflates, and the like.
  • Those functional groups which contain an OH group may be partially or fully neutralized; i.e. by reaction with a base a part or all of the OH groups may be converted into OM groups wherein M is a metal cation equivalent (i.e.
  • aryl groups may carry fur- ther radicals, for example radicals selected from alkyl, e.g.
  • the aryl groups in the polyarylether surface-active compounds are phenyl or naph- thyl rings, in particular phenyl rings, which may be substituted as defined above.
  • at least 50%, in particular at least 80% of the aryl groups carry one or more, e.g. 1 or 2, preferably 1 , ether substituent as defined above or in the following.
  • the ether substituents are preferably of formula - ⁇ 0-A- ⁇ x -Y, wherein each A is independently selected from C 2 -C5-alkylene, each x is independently 1 to 100 and Y is selected from
  • A is selected from 1 ,2-ethylene and 1 ,2-propylene and is in particular 1 ,2-ethylene.
  • x is from 1 to 50.
  • R is preferably H.
  • R' is preferably Ci-C 4 -alkyl.
  • linking groups between the aryl rings are alkylene groups, especially CH2.
  • aryl groups or a part of the aryl groups carry further substituents, these are preferably selected from Ci-C2o-alkyl, halogen, hydroxyl, SO3H, OSO3H, CN and Ci-C 4 -alkoxy.
  • aryl groups in the polyarylether surface-active compounds which do not carry an ether group as defined above are either unsubstituted (of course apart from their attachment points to the linking groups) or preferably carry 1 , 2 or 3, preferably 1 or 2, of the above further substituents.
  • these substituents are selected from Ci-C2o-alkyl, halogen, hydroxyl, SO3H, OSO3H, CN and Ci-C 4 -alkoxy, in particular from Ci-C2o-alkyl, hydroxyl and SO3H, and in particular from C 4 -C2o-alkyl and hydroxyl.
  • the sulfonate groups might be bound directly to the aryl groups or via a linking group, such as a Ci-Cio-alkylene group or a polyether group - ⁇ 0-A-] x -, wherein A and x are as defined above.
  • M is a metal cation equivalent (i.e. (M m+ )i/ m , where m is the valence of the metal cation) or an ammonium cation (NR a R b R c R d ) + , where R a , R b , R c and R
  • Suitable bases are for example (M m+ )(OH-) m , (M m+ )(C03 " ) m /2, ammonia, an amine NR a R b R c , etc., e.g. LiOH, NaOH, KOH, Na 2 C0 3 , K2CO3, NH 3 , triethylamine, Hunig's base etc.
  • Preferred polyarylsulfonates are the Glydol® brands from Zschimmer & Schwarz, especially Glydol® N1055.
  • Poly(alkyleneoxide) blockcopolymers are diblock, triblock or tetrablock copolymers or copolymers with a higher block number containing blocks of at least two different polymerized al- kyleneoxides. In order to have amphiphilic properties, they contain at least one polyethyleneox- ide (PEO) block.
  • the other block(s) is/are preferably selected from polypropyleneoxide (PPO), poly(1 ,2-pentyleneoxide) block(s) and the like, and is/are in particular polypropyleneoxide block(s).
  • Pluronics® are poloxamers. Poloxamers are nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene (polypropylene oxide; PPO) flanked by two hydrophilic chains of polyoxyethylene (polyethylene oxide; PEO).
  • PPO polypropylene oxide
  • PEO polyoxyethylene oxide
  • the Pluronics® contain 10 to 100, preferably 15 to 70, in particular 20 to 60 PO repeating units in the central PPO block and on each side 10 to 150, preferably 20 to 100 EO repeating units in each PEO block.
  • Tetronics® are X-shaped copolymers with four PPO-PEO blocks bonded to a central ethylene diamine linker.
  • the arylsulfonic acid is preferably selected from naphthylsulfonic acid, phenylsulfonic acid and phenolsulfonic acid and in particular from 1 - and especially 2-naphthylsulfonic acid and phenolsulfonic acid.
  • Suitable aldehydes are for example formaldehyde, acetaldehyde, propionaldehyde or butyralde- hyde.
  • the aldehyde is preferably formaldehyde.
  • the further compound different from arylsulfonic acids and aldehydes is preferably selected from urea, urea derivatives, amines having at least two primary and/or secondary amino groups, melamine, melamine derivatives and hydroxyaromatic compounds, such as phenol, resorcinol, hydroquinone, catechol or the naphtholes.
  • urea derivatives of components are for example
  • R 1 and R 2 and/or R 3 and R 4 each together are C2-Cs-alkylene, with one methylene group (i.e., a Chb group in the alkylene chain) optionally being replaced by a carbonyl group;
  • R 1 and R 3 together are C2-Cs-alkylene, with one methylene group (i.e.,
  • R 1 and R 2 and/or R 3 and R 4 in each case together with the nitrogen atom to which they are attached, form a 5- or 6-membered unsaturated aromatic or nonaromatic ring which may comprise one or two further nitrogen atoms or a sulfur atom or oxygen atom as ring member (i.e., R 1 and R 2 , and/or R 3 and R 4 , together with the nitrogen atom to which they are attached, stand for a 5- or 6-membered unsaturated aromatic or nonaromatic ring which is attached via N and may comprise one or two further nitrogen atoms or one sulfur atom or oxygen atom as ring member);
  • R 5 and R 6 and/or R 7 and R 8 each together are C2-Cs-alkylene, with one methylene group (i.e., a Chb group in the alkylene chain) optionally being replaced by a carbonyl group;
  • R 5 and R 7 together are C2-Cs-alkylene, with one methylene group (i.e., a Chb group in the alkylene chain) optionally being replaced by a carbonyl group;
  • R 5 and R 6 and/or R 7 and R 8 in each case together with the nitrogen atom to which they are attached, form a 5- or 6-membered unsaturated aromatic or nonaromatic ring which may comprise one or two further nitrogen atoms or a sulfur atom or oxygen atom as ring member (i.e., R 5 and R 6 , and/or R 7 and R 8 , together with the nitrogen atom to which they are attached, stand for a 5- or 6-membered unsaturated aromatic or nonaromatic ring which is attached via N and may comprise one or two further nitrogen atoms or one sulfur atom or oxygen atom as ring member);
  • R 9 and R 12 together are C2-Cs-alkylene, with one methylene group (i.e. a Chb group in the alkylene chain), optionally being replaced by a carbonyl group;
  • R 9 and R 10 and/or R 12 and R 13 in each case together with the nitrogen atom to which they are attached, form a 5- or 6-membered unsaturated aromatic or nonaromatic ring which may further comprise one further nitrogen atom, sulfur atom or oxygen atom as ring member (i.e., R 9 and R 10 , and/or R 12 and R 13 , together with the nitrogen atom to which they are attached, stand for a 5- or 6-membered unsaturated aromatic or nonaromatic ring which is attached via N and may comprise one or two further nitrogen atoms or one sulfur atom or oxygen atom as ring member); or
  • R 14 -0-CO-0-R 15 carbonic esters of the formula R 14 -0-CO-0-R 15 , in which R 14 and R 15 independently of one another are selected from Ci-Cio-alkyl, aryl, and aryl-Ci-C 4 -alkyl, or R 14 and R 15 together are C2-Cs-alkylene.
  • Amines having at least two primary and/or secondary amino groups are for example amines of the formula
  • A is a divalent aliphatic, alicyclic, aliphatic-alicyclic, aromatic or araliphatic radical, with the aforementioned radicals also possibly being interrupted by a carbonyl group or by a sul- fone group and/or possibly substituted by 1 , 2, 3 or 4 radicals selected from Ci-C4-alkyl; or is a divalent radical of the formula
  • each X is independently O or NR C , in which R c is H, Ci-C4-alkyl, C2-C4-hydroxyalkyl or Ci- C 4 -alkoxy, and preferably is H, Ci-C 4 -alkyl or Ci-C 4 -alkoxy;
  • each B independently of one another is C2-C6-alkylene
  • m is a number from 1 to 100; preferably 1 to 80, and more particularly 1 to 20; and R a and R b independently of one another are H , Ci-C 4 -alkyl, C2-C 4 -hydroxyalkyl or Ci-C 4 -alkoxy, and preferably are H , Ci-C 4 -alkyl or Ci-C 4 -alkoxy, such as 1 ,2-ethylenediamine, 1 ,2- and 1 ,3-propylenediamine, 2,2-dimethyl-1 ,3-propanediamine, 1 ,4-butylenediamine, 1 ,5-pentylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, 2,2,4- or 2,4,4-trime- thyl-1 ,6-hexamethylenediamine, 1 ,5-diamino-2-methylpentane
  • Melamine derivatives are for example benzoguanamine, substituted melamines, and melamine condensates, such as melam, melem, melon, and higher condensates.
  • Melam empirical formula C6-H9N11
  • Melem empirical formula ⁇ - ⁇
  • Melem is the tri-amino-substituted tri-s-triazine
  • the further compound different from arylsulfonic acids and aldehydes is in particular selected from urea and phenol.
  • the condensation products of at least one arylsulfonic acid, at least one aldehyde and optionally at least one further compound different from arylsulfonic acids and aldehydes which is capable of undergoing condensation with the arylsulfonic acid(s) and/or the aldehyde(s) the arylsulfonic acid is in particular a condensation product of naphthylsulfonic acid and formaldehyde, such as the Tamol® N brands from BASF, or a condensation product of phenolsulfonic acid, formaldehyde, urea and phenol, such as the Tamol® DN or PP brands from BASF.
  • Suitable bases are for example (M m+ )(OH-) m , (M m+ )(C03 " ) m /2, ammonia, an amine NR a R b R c , etc., e.g. LiOH, NaOH, KOH, Na 2 C0 3 , K 2 C0 3 , NH 3 , triethylamine, Hunig's base etc.
  • the group -OR is group -OM wherein M is a metal cation equivalent (i.e. (M m+ )i/m, where m is the valence of the metal cation) or an ammonium cation (NR a R b R c R d ) + , where R a , R b , R c and R d , independently of each other, are hydrogen, Ci-Cio-alkyl or C1-C10- alkoxy.
  • Such groups -OM are generally obtained by partially or fully neutralizing polyarylethers containing one or more OH groups (i.e. containing a radical R and in which R is H); i.e.
  • a base such as (M m+ )(OH-) m , (M m+ )(C03 " ) m /2, ammonia, an amine NR a R b R c , etc., e.g. LiOH, NaOH, KOH, Na 2 C0 3 , K2CO3, NH 3 , triethylamine, Huhig's base etc., so that a part or all of the OH groups are converted into OM groups.
  • a base such as (M m+ )(OH-) m , (M m+ )(C03 " ) m /2, ammonia, an amine NR a R b R c , etc., e.g. LiOH, NaOH, KOH, Na 2 C0 3 , K2CO3, NH 3 , triethylamine, Huhig's base etc.
  • R is preferably H.
  • R' is preferably Ci-C4-alkyl.
  • aryl groups or a part of the aryl groups carry further substituents, these are preferably lected from Ci-C2o-alkyl, halogen, hydroxyl, SO3H, OSO3H, CN and Ci-C4-alkoxy.
  • aryl groups in the polyarylether surface-active compounds which do not carry an ether group as defined above are either unsubstituted (of course apart from their attachment points to the linking groups) or preferably carry 1 , 2 or 3, preferably 1 or 2, of the above further substituents.
  • these substituents are selected from Ci-C2o-alkyl, halogen, hydroxyl, SO3H, OSO3H, CN and Ci-C4-alkoxy, in particular from Ci-C2o-alkyl, hydroxyl and SO3H, and in particular from C4-C2o-alkyl and hydroxyl.
  • the polyarylether is obtainable by the condensation of
  • each R being independently H, a cationic equivalent (definition see above), Ci-C4-alkyl or optionally substituted phenyl;
  • “Monohydroxyaromatic compound” refers to an aromatic compound carrying only one hydroxyl group (and optionally other substituents different from OH).
  • the "monohydroxyaromatic derivative” in (1 ) and (2) is derived from such a monohydroxyaromatic compound.
  • the monohydroxyaromatic compound in (3) or from which (1 ) and (2) derive is for example a hydroxybenzene or a hydroxynaphthaline, preferably a hydroxybenzene, where the phenyl or naphthyl ring, apart from the hydroxyl group (and the mandatory Cio-C2o-alkyl group(s) in (3)), may carry 1 or 2 fur- ther substituents such as Ci-C4-alkyl, Ci-C4-haloalkyl, cyano, Ci-C4-alkoxy, Ci-C4-haloalkoxy, and the like.
  • the phenyl or naphthyl rings do not carry any further substituents.
  • the C2-Cs-alkyl group is preferably a C2-C3-alkyl group, more preferably a C2- alkyl group.
  • the diol precursor is preferably selected from ethylene oxide and propylene oxide and is in particular ethylene oxide.
  • the compound (2) contains preferably from 5 to 50, in particular from 10 to 40 repeating units of the diol precursor; i.e. is obtained by reacting 1 mole of hydroxyaro- matic compound with 5 to 50, preferably 10 to 40 moles of diol precursor.
  • the monohydroxyaromatic compound carries preferably just one Cio-C2o-alkyl group.
  • the alkyl group is preferably a Cio-Ci6-alkyl group, and especially a Ci2-alkyl group.
  • Suitable aldehydes (4) are for example formaldehyde, acetaldehyde, propionaldehyde or butyr- aldehyde or compounds from which these aldehydes are accessible (called aldehyde sources).
  • aldehyde sources are gaseous formaldehyde, formalin solutions, formaldehyde oligomers, such as trioxane or tetraoxane, and formaldehyde polymers, such as paraform- aldehyde.
  • formaldehyde which, for practical reasons, is preferably used in form of trioxane or paraformaldehyde.
  • polyarylether is obtainable by the condensation of
  • the at least one monohydroxyaromatic derivative (1 ) is used in molar excess to the overall amount of (2) and (3).
  • (2) and (3) are preferably used in a molar ratio of from 10:1 to 1 :10, more preferably 5:1 to 1 :5 and in particular from 2:1 to 1 :2.
  • the aldehyde (4) is used in a sufficiently high amount to allow coupling of compounds (1 ), (2) and (3).
  • the condensation reaction is generally carried out in the presence of a catalyst.
  • Suitable catalysts for such condensation reactions are known and are for example protic acids, such as sulfuric acid, phosphoric acid, sulfonic acids, such as methane sulfonic acid, trifluoromethane sul- fonic acid or toluenesulfonic acid, and carboxylic acids, such as trifluoroacetic acid; or Lewis acids, such as aluminum trihalides, e.g. aluminum trichloride or tribromide, boron trihalides, such as boron trifluoride or trichloride, or iron(lll) halides, such as ferric chloride or bromide.
  • protic acids such as sulfuric acid, phosphoric acid, sulfonic acids, such as methane sulfonic acid, trifluoromethane sul- fonic acid or toluenesulfonic acid
  • carboxylic acids such as trifluoroacetic acid
  • the condensation reaction is generally carried out at elevated temperature, e.g. at from 60 to 180°C, preferably from 90 to 150°C.
  • the product can be neutralized, e.g. by addition of a base, e.g. of aqueous NaOH, KOH, Na2C03 or the like.
  • a base e.g. of aqueous NaOH, KOH, Na2C03 or the like.
  • the polyarylether has preferably a number average molecular weight M n of from 1000 to 50000, more preferably from 3000 to 30000 and in particular from 5000 to 20000.
  • the polyarylether has preferably a dispersity (M w /M n ; M w being the weight average molecular weight) of from 1 to 10, in particular from 1 to 5 and specifically from 1 .1 to 2.
  • Solid sodium polytungstate SPT
  • sodium metatungstate SPT
  • 3Na2W04-9W03-H 2 0 or Na6[H 2 Wi 2 04o] is a 12-fold aggregated isopolytungstate with a molar mass of 2986.12 g/mol.
  • the structure of polytungstate is modelled using octahedra in which the oxygen atoms are located at the corners and the tungsten atoms at the center of the octahedra.
  • the oxygen atoms When represented as a spherical model, the oxygen atoms form a dense spherical shell while the tungsten atoms fill the open spaces in the octahedra. Because of this structure this substance may be considered a true metatungstate, represented structurally as Na6[H2Wi204o].
  • Solid SPT has the form of white crystals and aqueous SPT is a light yellow-green transparent solution. Due to its very high solubility in water (max. density 3.1 g/cm 3 ), SPT is widely used as a heavy liquid for gravity separation (sink swim analysis) and density gradient centrifugation mainly used in the mineral industry (B. Plewinsky, R. Kamps, Makromol. Chem 1984, 185, 1429-1439; M.R. Gregory, K.A. Johnston, New Zealand Journal of Geology and Geophysics, 1987, 30, 317-320).
  • Aqueous SPT is non-toxic, non-flammable, non-corrosive, odorless, environmentally benign and reusable. Additionally it has a low viscosity, even at high concentrations.
  • the polytungstate is preferably one analogous to SPT (i.e. M6[H2Wi204o], wherein M is a cation equivalent), wherein the counter cation (equivalent) is not restricted to sodium, but can be any counter cation, provided that the corresponding polytungstate is soluble in aqueous media.
  • Suitable counter cations are metal cation equivalents, i.e. (M m+ )i/ m , wherein M is a metal and m is the valence of the metal; and ammonium cations
  • NR a R b R c R d NR a R b R c R d + , where R a , R b , R c and R d , independently of each other, are hydrogen, Ci-Cio-alkyl or Ci-Cio-alkoxy.
  • Preferred metal cation equivalents are alkali metal cations, such as Li + , Na + or K + , and alkaline earth metal cation equivalents, such as (Mg 2+ )i/2 or Ca 2+ )i/2; alkali metal cations being preferred.
  • Aqueous media/solutions are defined below.
  • the cation equivalent is selected from Li + (the polytungstate thus being lithium polytungstate), Na + (the polytungstate thus being sodium polytungstate), K + (the polytungstate thus being potassium polytungstate) or NH4 + (the polytungstate thus being ammonium polytungstate).
  • the polytungstate is sodium polytungstate (SPT).
  • the solution of the polytungstate is preferably aqueous.
  • the solvent is either water or a mixture of water and at least one water-miscible organic solvent.
  • Suitable organic solvents are for example lower alkanols, such as methanol, ethanol, propanol or isopropanol, polyols, such as ethylene glycol, propylene glycol, diethylene glycol or triethylene glycol, cyclic ethers, such as tetrahydrofuran, 1 ,3- or 1 ,4-dioxane, amides, such as dimethylformamide, and dimethylsulfoxide. Among these, preference is given to the above alkanols.
  • the aqueous solution contains at least one water-soluble organic solvent, this is preferably present in an overall amount of at most 50% by weight, preferably at most 20% by weight and in particular at most 10% by weight, based on the total weight of water plus organic solvent.
  • the liquid so- lution contains water as solvent, and no organic solvent.
  • the solution of the polytungstate preferably contains at least one surface-active compound.
  • Preferred surface-active compounds are those mentioned above which are brought into contact with the composition containing semi-conducting and/or metallic single-walled carbon nano- tubes and (optionally) undesired carbonaceous material.
  • the surface-active compounds brought into contact with the composition containing semi-conducting and/or metallic single-walled carbon nanotubes and (optionally) undesired carbonaceous material and the surface-active compounds contained in the solution of the polytungstate are the same.
  • the solution of the polytungstate preferably contains at least one surface-active compound in an amount of from 0.05 to 5% by weight, more preferably from 0.5 to 5 % by weight, and in particular from 1 to 3 % by weight, based on the total weight of the solution of the polytungstate.
  • the solution of the polytungstate has at least one zone with a density which corresponds to the density of a complex formed by semi-conducting single-walled carbon nanotubes and the at least one surface-active compound. This is generally in the range of from 1.05 to 1.40 g/cm 3 , specifically from 1.10 to 1.30 g/cm 3 .
  • the solution of the polytungstate has preferably at least one zone with a density of from 1 .05 to 1.40 g/cm 3 , specifically of from 1.10 to 1.30 g/cm 3 .
  • the role of the polytungstate is not limited to that of a density medium.
  • one aspect of the separation effect of the polytungstate is its pH in solution.
  • Aqueous polytungstate solutions are acidic, the exact pH depending, of course, on the respective concentra- tion (the higher the concentration, the lower the pH). It has been observed that even when using a single layer of polytungstate with a single density (i.e. not a density gradient; the density being in the range of the isopycnic point of the complex formed by semi-conducting or metallic SWNTs; i.e. from 1 .05 to 1 .3 g/cm 3 ), semi-conducting and metallic SWNTs are nevertheless separated.
  • the metallic SWNTs (as well as other undesired carbonaceous material) precipitate.
  • acidic polytungstate solutions affect the complex formed by metallic SWNTs (and other carbonaceous material) and surfactant(s) if these are those preferably used for obtaining semi-conducting SWNTs (e.g. the above-described polyarylethers), while the complex formed by semi-conducting SWNTs and surfactant(s) stays essentially unaffected.
  • the solution of the polytungstate/surface-active compound has at least one zone with a pH of below 7, preferably of at most 6, more preferably with a pH from 1 to 6, even more preferably from 1 .5 to 5.5, even more preferably from 1 .5 to 3.5, even more preferably from 1 .5 to 3.0 (and of course with the proviso that the pH is not neutralized by the composition containing the material to be separated).
  • a pH of below 7 preferably of at most 6, more preferably with a pH from 1 to 6, even more preferably from 1 .5 to 5.5, even more preferably from 1 .5 to 3.5, even more preferably from 1 .5 to 3.0
  • centrifugation is carried out with a mean acceleration of from 100 to 300000 x g, preferably of from 2000 to 50000 x g, in particular of from 5000 to 15000 x g.
  • the centrifugation time depends on various factors, such as acceleration, the components in the composition from which the semi-conducting SWCNTs are to be separated, the pH of the polytungstate solution etc. and may vary in wide ranges, such as from 0.5 to 30 h or 5 to 25 h or 10 to 20 h. The optimum time can be readily determined by preliminary tests. If the pH of the polytungstate solution is below 2, rather shorter centrifugation times are expedient because the polytungstate, especially SPT, may be prone to some degradation at very low pH values. If the temperature of the centrifugation is above 25 °C, rather shorter centrifugation times are expedient.
  • one or more layers of a solution of the polytungstate are placed in a centrifugation tube; whereas one layer is particular preferred. If two or more layers are used, these are placed on top each other. In case that two or more layers are used, the layers have different densities, so that they can form a density gradient, and are preferably placed in order of decreasing densities, the layer with the highest density being at the bottom of the centrifugation tube and the layer with the lowest density being at the top of the centrifugation tube.
  • this has a density of preferably from 1.0 to 3.0 g/cm 3 , more preferably 1 .0 to 2.0 g/cm 3 , even more preferably 1.0 to 1 .5 g/cm 3 , even more preferably 1.0 to 1 .4 g/cm 3 , even more preferably 1 .05 to 1.3 g/cm 3 , specifically from 1 .1 to 1.25 g/cm 3 .
  • one of these layers has a density of preferably from 1.0 to 3.0 g/cm 3 , more preferably 1.0 to 2.0 g/cm 3 , even more preferably 1 .0 to 1 .5 g/cm 3 , even more preferably 1 .0 to 1.4 g/cm 3 , even more preferably 1.05 to 1 .3 g/cm 3 , specifically from 1.1 to 1 .2 g/cm 3 .
  • this layer in not the bottom layer, but the top or one of the middle layers.
  • the densities of the bottom layer and the top layer differ by at least 0.1 g/cm 3 , preferably by at least 0.2 g/cm 3 and in particular by at least 0.5 g/cm 3 , e.g. by at least 0.7 g/cm 3 ; the bottom layer suitably having the highest density and the top layer the lowest.
  • the densities of the bottom layer and the top layer differ by 0.1 to 2.0 g/cm 3 , more preferably by 0.2 to 2.0 g/cm 3 , even more preferably by 0.5 to 2.0 g/cm 3 .
  • step (iii) placing the dispersion obtained in step (i) on or into the solution provided in step (ii);
  • step (iv) submitting the composition obtained in step (iii) to a centrifugation step, whereas the cen- trifugation is performed at a temperature of > 25°C;
  • nanotubes from the fraction or fractions enriched in other carbonaceous material; in particular from the fraction or fractions enriched in metallic single-walled carbon nanotubes and from the fraction or fractions containing other carbonaceous material, if present;
  • step (vi) if desired repeating steps (i) to (v) with one or more of the fractions obtained in step (v).
  • the liquid medium of step (i) is preferably aqueous, i.e. either water or a mixture of water and at least one water-soluble organic solvent.
  • Suitable organic solvents are for example lower alka- nols, such as methanol, ethanol, propanol or isopropanol, polyols, such as ethylene glycol, propylene glycol, diethylene glycol or triethylene glycol, cyclic ethers, such as tetrahydrofuran, 1 ,3- or 1 ,4-dioxane, amides, such as dimethylformamide and N-methylpyrrolidone, lower ketones, such as acetone and ethylmethylketone, and dimethylsulfoxide. Among these, preference is given to the above alkanols.
  • the aqueous medium contains at least one water-soluble organic solvent, this is preferably present in an overall amount of at most 50% by weight, preferably at most 20% by weight and in particular at most 10% by weight, based on the total weight of water plus organic solvent.
  • the liquid medium contains only water as solvent, and no organic solvent.
  • the composition containing semi-conducting and/or metallic single-walled carbon nanotubes, calculated as solid carbon matter is preferably used in an amount of from 0.001 to 2 % by weight, more preferable from 0.01 to 2 % by weight, in particular from 0.1 to 1 % by weight, based on the total weight of the dispersion; i.e. the dispersion obtained in step (i) contains the composition containing semi-conducting and/or metallic single-walled carbon nanotubes, calculated as solid carbon matter, in an amount of from 0.01 to 2 % by weight, in particular from 0.1 to 1 % by weight, based on the total weight of the dispersion.
  • the at least one surface-active compound is used in step (i) in an amount of from 0.05 to 5% by weight, more preferably of from 0.5 to 5 % by weight, in particular of from 1 to 3 % by weight, based on the total weight of the dispersion; i.e. the dispersion obtained in step (i) contains the at least one surface-active compound in an amount of from 0.05 to 5% by weight, in particular from 1 to 5 % by weight, based on the total weight of the dispersion.
  • Dispersion of the composition containing semi-conducting and/or metallic single-walled carbon nanotubes and (optionally) other carbonaceous material can be carried out by any means which ensures a fine and even distribution of the material in the dispersion, such as ultransonic treat- ment (ultrasonic horn, ultrasonic bath, tip sonication and the like) or effective mechanical stirring or agitation, e.g. with an Ultra-Turrax® (from IKA®-Werke GmbH & Co. KG, Germany) or a Di- spermat® (from Getzmann, Germany). Both pulsed or continuous treatments may be applied. Ultrasonic treatment is preferred.
  • step (i) comprises providing a mixture containing semi-conducting and/or metallic single-walled carbon nanotubes and (optionally) other carbonaceous material, water and at least one surface-active compound and subjecting the mixture to an ultrasonic treatment.
  • the temperature of the CNT dispersion, containing semi-conducting and metallic sin- gle-walled carbon nanotubes and/or optionally other carbonaceous material and at least one surface-active, during its preparation in step (i) is below 60°C, more preferably below 40°C, more preferably below 30°C.
  • the preparation of step (i) is carried out in an ice- cooled water bath.
  • the pH of the CNT dispersion, containing semi-conducting and metallic single-walled carbon nanotubes and/or optionally other carbonaceous material and at least one surface-active, prepared in step (i) is below 7, more preferably below 6, even more preferably the pH is in the range from 2 to 5, even more preferably in the range from 3 to 4.
  • step (ii) preferably one or more layers of a solution of the polytungstate are placed in a centrifugation tube. More preferable one layer of the polytungstate is placed in a centrifugation tube.
  • the density separation step (iv) is to be density gradient centrifugation, preferably two or more layers of a solution of the polytungstate are placed on top each other. In the latter case, i.e. in case that two or more layers are used, the layers have different densities and are preferably placed in order of decreasing densities, the layer with the highest density being at the bottom of the centrifugation tube and the layer with the lowest density being at the top of the centrifugation tube.
  • the densities of the bottom layer and the top layer differ preferably by at least 0.1 g/cm 3 , more preferably by at least 0.2 g/cm 3 and in particular by at least 0.5 g/cm 3 , e.g. by at least 0.7 g/cm 3 .
  • step (iii) the dispersion obtained in step (i) is placed on or into the solution provided in step (ii). This is done by usual means, such as overlaying the solution of step (ii) with the dispersion of step (i), e.g. with a (micro)pipette or a (micro)syringe or the like. If the dispersion of step (i) is placed "into" the solution provided in step (ii), this is usually done by first overlaying at least a part of the solution of step (ii) with the dispersion of step (i) and then overlaying the latter with the remainder of the solution of step (ii) or just with water optionally containing surface-active compounds or with the solvent used for preparing the solution of step (ii).
  • step (i) placing the dispersion of step (i) "into" the solution provided in step (ii) can be carried out by simply mixing dispersion and solution.
  • step (iv) the centrifugation is performed at a temperature of > 20°C; preferably of at least 22°C, more preferably of at least 25°C, preferably of > 25°C, more preferably of least 28°C, more preferably of at least 30°C.
  • the centrifugation is performed in a temperature range from >20 to 60°C, more preferably from at least 25 to 60°C, more preferably from > 25 to 60°C, more preferably from 22 to 50°C, more preferably from at least 25 to 50°C, more prefera- bly from > 25 to 50°C, more preferably from 30 to 50°C, even more preferably from 22 to 45°C, even more preferably from 25 to 45°C, even more preferably from >25 to 45°C, even more preferably from 30 to 45°C, even more preferably from 25 to 40°C, even more preferably from >25 to 40°C, in particular from 30 to 40°C.
  • step (v) the fraction or fractions enriched in semi-conducting single-walled carbon nanotubes is/are separated from the fraction or fractions enriched in other carbonaceous material.
  • Convenient measures depend on the density separation step (iv) applied. For instance, density gradient centrifugation usually yields visible bands having a different optical aspect which can be sepa- rated by carefully removing the single layers, e.g. with a (micro)pipette or (micro)syringe or a piston gradient fractionator or another suitable means. This process can also be automatized.
  • the fraction enriched in semi-conducting single-walled carbon nanotubes is found in the region with a density of from 1.05 to 1 .3 g/cm 3 , while the other carbonaceous materials are found at the bottom of the centrifugation tube. This makes separation of the fraction enriched in semi-conducting single-walled carbon nanotubes much easier than in the density gradient ultracentrifugation methods of the prior art.
  • fraction(s) enriched in semi-conducting single-walled carbon nanotubes obtained in step (v) or other fractions can be resubmitted to steps (i) to (iv) in order to enhance purity and/or yield of the desired material, especially the semi-conducting SWCNTs.
  • the fraction(s) to be resubmitted to steps (i) to (iv) are preferably first freed from solvent, polytungstate and surfactant.
  • the fraction(s) containing the semi-conducting SWCNTs are diluted with water and centrifuged.
  • the semi-conducting SWCNTs concentrate at the bottom in solid form.
  • the supernatant is discarded, the solid is washed with water which optionally contains surfactant and redispersed in analogy to step (i). All or selected steps may be repeated multiple times.
  • the polytungstate removed from the process may be purified and reused.
  • the whole process can also be carried out in a semi-continuous or continuous manner.
  • the invention relates to semi-conducting single-walled carbon nanotubes, obtainable by the method of the invention.
  • the semi-conducting single-walled carbon nanotubes of the in- vention have a particularly high purity.
  • they have a purity of at least 95% by weight, more preferably of at least 98% by weight, even more preferably of at least 99% by weight, even more preferably of at least 99.2% by weight, in particular of at least 99.5% by weight.
  • they contain less than 1 % by weight, more preferably less than 0.9% by weight and in particular less than 0.8% by weight of metallic single-walled carbon nanotubes.
  • the invention also relates to the use of semi-conducting single-walled carbon nanotubes of the invention in electronic devices, optical devices, optoelectronic devices or energy storage devices; in particular in transistors, especially FETs and TFTs (for example for the use in back planes), memory devices, sensors, photodetectors, or solar cells.
  • the semi-conducting single-walled carbon nanotubes of the invention are in particular used in transistors; in particular in field-effect transistors (FETs), especially in FETs made from individual CNTs (see Park, H. et al.; Nature Nanotechnology 2012, 7,787-791 ) and in FETs made from CNT networks (Lau, P. H. et al.; Nano Lett. 2013, 13, 3864-3869).
  • FETs field-effect transistors
  • OLEDs Organic light-emitting diodes
  • OLEDs are especially of interest as an alternative to cathode ray tubes and liquid-crystal displays for producing flat visual display units.
  • devices which comprise OLEDs are suitable especially for mobile applications, for example for applications in cell phones, laptops, etc.
  • the semi-conducting single-walled carbon nanotubes of the invention are furthermore suitable for the use in memory devices, sensors (e. g. chemical sensors, temperature sensors, pressure sensors), photodetectors, solar cells and thin-film transistors (TFTs).
  • sensors e. g. chemical sensors, temperature sensors, pressure sensors
  • TFTs thin-film transistors
  • the semi-conducting single-walled carbon nanotubes of the invention may be applied for example via spin-coating, slot-die coating, screen printing, inkjet printing, flexographic printing, gravure printing, doctor blading, spray coating, drawdown-bar coating, aerosol deposition and the like. It is also possible to place the semiconducting single-walled carbon nanotubes of the invention on specific positions on a function- alized substrate via ion-exchange techniques as described in Park, H. et al.; Nature Nanotech- nology 2012, 7,787-791 . By this approach, arrays of individually positioned semi-conducting single-walled carbon nanotubes can be obtained.
  • Field-effect transistors generally comprise a substrate having at least one gate structure, a source electrode and a drain electrode as well as an insulating layer and at least one semicon- ductor material; in the present case semiconducting SWCNTs.
  • the semi-conducting SWCNTs can be in principle used as n-type semiconductors or as p-type semiconductors. Whether they act as n-type semiconductor or as p-type semiconductors depends inter alia on the employed transistor (contact materials, surface) and the measuring con- ditions (vacuum, air).
  • the semi-conducting SWCNTs of the invention may be used, for example, for the production of integrated circuits (ICs), for which customary n-channel MOSFETs (metal oxide semiconductor field-effect transistors) have been used to date. These are then CMOS-like semiconductor units, for example for microprocessors, microcontrollers, static RAM and other digital logic circuits. They are especially suitable for use in displays (specifically large-surface area and/or flexible displays), RFID tags, smart labels and sensors.
  • ICs integrated circuits
  • MOSFETs metal oxide semiconductor field-effect transistors
  • the optical device is for example an electroluminescent arrangement.
  • Electroluminescent ar- rangements generally comprise an upper electrode, a lower electrode, wherein at least one of said electrodes is transparent, an electroluminescent layer and optionally an auxiliary layer, wherein the electroluminescent arrangement comprises at least one semiconductor material; in the present case semi-conducting SWCNTs.
  • the electroluminescent arrangement is in form of an organic light-emitting diode (OLED).
  • the PAE was prepared according to the following phosphorylation and polycondensation procedure:
  • a reactor, equipped with heating and stirrer was charged with 127 g of polyphosphoric acid (specified to have 85 % P2O5 content). The content was heated to 90°C. 138.2 g (1 mol) of phe- noxyethanol was added to the stirred reaction mixture through a period of 1 hour. After the addition was finished, the reaction mix was stirred for an additional hour.
  • the reaction product contained 75 %-wt. of phenoxyethanol phosphoric acid monoester (ester of 1 mol of phenoxy- ethanol with 1 mol of phosphoric acid), 5 %-wt. of bis(phenoxyethanol)phosphoric acid ester (ester of 2 mols phenoxyethanol with 1 mol of phosphoric acid), 1 %-wt. of unreacted phenoxy- ethanol and 19 %-wt. of unreacted phosphoric acid.
  • the reaction product of the phosphorylation was used without further purification as starting material for the following polycondensation step.
  • HiPco SWCNTs were purchased from Nanolntegris (Batch# HS 28030). The as-produced SWCNTs were dispersed in an aqueous solution containing 2 wt% of PAE by horn sonication for 1 h at 100% amplitude (Dr. Hielscher UP200s) starting with 0.5 wt% of raw nanotube material in a total of 50 g of dispersion. During sonication the vials were placed in ice-cooled water bath. The pH of the dispersion was adjusted to pH 4 by adding aliquots of 1 M HCI.
  • Centrifugation process For centrifugation, a water based solution of sodium polytungstate (SPT) (TC Tungsten Compounds) 25.5 wt% also containing 2 wt% of PAE was prepared. The pH-value of this SPT column was controlled by adding small aliquots of 1 M HCI. The centrifugation vessel was loaded with 4.2 ml of SPT (pH 2.0) and 0.3 ml of the nanotube dispersion (pH 4) on top. Centrifugation (Beckman Coulter Optima XL) was performed applying a centrifugal field of approximately 10,000 x g for 18 h to separate nanotubes in a Beckman Coulter SW 60Ti ro- tor.
  • SPT sodium polytungstate
  • Table 1 Summarizing the temperature dependent semiconducting purity. For the tested temperatures the purity of the SWCNT fractions was evaluated by integration of the S22 and M1 1 peak areas (without background subtraction). The calculated areas were used to form the
  • A(M1 1 )/A(S22) ratio The smaller this ratio is the higher is the semiconducting purity of the extracted fractions at pH 2.0.
  • the M1 1/S22 area ratio is inversely proportional to the semiconducting purity.
  • the relative comparison of the determined ratios can therefore be used to further classify the semiconducting purity in dependence on the centrifugation temperature.
  • the relative ratio comparison was defined as relative purity indicator varying with 1 being the highest pu- rity and 0.70 being the lowest purity.
  • SPT TC Tungsten Compounds
  • pH-value of this SPT column was controlled by adding small aliquots of 1 M HCI.
  • the centrifugation vessel was loaded with 3.8 ml of SPT (pH 4.3) and 0.7 ml of the nanotube dispersion (pH 4) on top. Centrifugation (Beckman Coulter Optima XL) was performed applying a centrifugal field of approximately 10,000 x g for 25 h to separate nanotubes in a Beckman Coulter SW 60Ti rotor.
  • Table 1 Summarizing the temperature dependent semiconducting purity. For the tested temperatures the purity of the SWCNT fractions was evaluated by integration of the S22 and M1 1 peak areas (without background subtraction). The calculated areas were used to form the
  • A(M1 1 )/A(S22) ratio The smaller this ratio is the higher is the semiconducting purity of the ex- tracted fractions at pH 4.3.
  • the M1 1/S22 area ratio is inversely proportional to the semiconducting purity.
  • the relative comparison of the determined ratios can therefore be used to further classify the semiconducting purity in dependence on the centrifugation temperature.
  • the relative ratio comparison was defined as relative purity indicator varying with 1 being the highest pu- rity and 0.72 being the lowest purity.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Nanotechnology (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Carbon And Carbon Compounds (AREA)

Abstract

La présente invention concerne un procédé de séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques les uns des autres et, le cas échéant, d'autres matériaux carbonés, ou de séparation de nanotubes de carbone à paroi unique semi-conducteurs d'un autre matériau carboné, par centrifugation effectuée par une température > 25 °C à l'aide d'une solution d'un polytungstate en tant que milieu de séparation. La présente invention concerne également des nanotubes de carbone à paroi simple semi-conducteurs pouvant être obtenus par ce procédé ; et l'utilisation de ces nanotubes de carbone à paroi simple semi-conducteurs, par exemple dans des dispositifs électroniques, des dispositifs optiques, des dispositifs optoélectroniques, des dispositifs de stockage d'énergie et équivalents.
PCT/EP2017/079989 2016-11-30 2017-11-22 Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polytungstate WO2018099774A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP16201422 2016-11-30
EP16201422.9 2016-11-30

Publications (1)

Publication Number Publication Date
WO2018099774A1 true WO2018099774A1 (fr) 2018-06-07

Family

ID=57517691

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2017/079989 WO2018099774A1 (fr) 2016-11-30 2017-11-22 Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polytungstate

Country Status (1)

Country Link
WO (1) WO2018099774A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109650372A (zh) * 2019-01-11 2019-04-19 武汉工程大学 一种一步制备多孔氮掺杂炭材料的方法
CN109708996A (zh) * 2018-12-20 2019-05-03 广东省微生物研究所（广东省微生物分析检测中心） 基于手性单壁碳纳米管的粘度探针及其应用
US11780023B2 (en) * 2021-12-14 2023-10-10 The Florida International University Board Of Trustees Aluminum boron nitride nanotube composites and methods of manufacturing the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120025150A1 (en) 2010-05-28 2012-02-02 Hersam Mark C Separation of single-walled carbon nanotubes by electronic type using block copolymers
WO2016024196A1 (fr) 2014-08-12 2016-02-18 Basf Se Tri de nanotubes de carbone
WO2016046153A1 (fr) 2014-09-23 2016-03-31 Basf Se Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polystungstate

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120025150A1 (en) 2010-05-28 2012-02-02 Hersam Mark C Separation of single-walled carbon nanotubes by electronic type using block copolymers
WO2016024196A1 (fr) 2014-08-12 2016-02-18 Basf Se Tri de nanotubes de carbone
WO2016046153A1 (fr) 2014-09-23 2016-03-31 Basf Se Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polystungstate

Non-Patent Citations (12)

* Cited by examiner, † Cited by third party
Title
A.A. GREEN; M.C. HERSAM, ADVANCED MATERIALS, vol. 23, 2011, pages 2185 - 2190
A.L. ANTARIS; J.-W. T. SEO; A.A. GREEN; M.C. HERSAM, ACSNANO, vol. 4, no. 8, 2010, pages 4725 - 4732
B. PLEWINSKY; R. KAMPS, MAKROMOL. CHEM, vol. 185, 1984, pages 1429 - 1439
HERSAM M C ET AL: "Sorting carbon nanotubes by electonic structure using density differentiation", NATURE NANOTECHNOLOGY, NATURE PUBLISHING GROUP, LONDON; GB, vol. 1, 4 October 2006 (2006-10-04), pages 60 - 66, XP002512670, DOI: 10.1038/NNANO.2006.52 *
HOMENICK ET AL., J. PHYS. CHEM C, 2014
K. YANAGI; T. LITSUKA; S. FUJII; H. KATAURA, J. PHYS. CHEM., vol. 112, 2008, pages 11889 - 18894
LAU, P. H. ET AL., NANO LETT., vol. 13, 2013, pages 3864 - 3869
M.R. GREGORY, K.A. JOHNSTON, NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS, vol. 30, 1987, pages 317 - 320
M.S. ARNOLD; A.A. GREEN; J.F. HULVAT; S.I. STUPP; M.C. HERSAM, NATURE NANOTECHNOLOGY, vol. 1, 2006, pages 60 - 65
MCCUTCHEON: "Emulsifiers & Detergents", vol. 1, 2008, MCCUTCHEON'S DIRECTORIES
PARK, H. ET AL., NATURE NANOTECHNOLOGY, vol. 7, 2012, pages 787 - 791
S. GHOSH; S.M. BACHILO; R.B. WEISMAN, NATURE NANOTECHNOLOGY, vol. 5, no. 6, 2010, pages 443 - 450

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109708996A (zh) * 2018-12-20 2019-05-03 广东省微生物研究所（广东省微生物分析检测中心） 基于手性单壁碳纳米管的粘度探针及其应用
CN109708996B (zh) * 2018-12-20 2021-05-04 广东省微生物研究所（广东省微生物分析检测中心） 基于手性单壁碳纳米管的粘度探针及其应用
CN109650372A (zh) * 2019-01-11 2019-04-19 武汉工程大学 一种一步制备多孔氮掺杂炭材料的方法
US11780023B2 (en) * 2021-12-14 2023-10-10 The Florida International University Board Of Trustees Aluminum boron nitride nanotube composites and methods of manufacturing the same

Similar Documents

Publication Publication Date Title
EP3197830B1 (fr) Séparation des nanotubes de carbone à paroi simple métalliques et des semi-conducteurs à l'aide d'un polytungstate
WO2018099774A1 (fr) Séparation de nanotubes de carbone à paroi unique semi-conducteurs et métalliques à l'aide d'un polytungstate
KR101494474B1 (ko) 풀러렌 유도체를 원료로 하는 풀러렌막 및 풀러렌 중합체 그리고 그들의 제조 방법
JP6465978B2 (ja) 有機薄膜トランジスタ、有機薄膜トランジスタの製造方法、有機薄膜トランジスタ用材料、有機薄膜トランジスタ用組成物、有機半導体膜、化合物
KR102363819B1 (ko) 실세스퀴옥산 복합 고분자 및 이의 제조방법
JP2012519758A5 (fr)
CN104797560A (zh) 芳香族酰亚胺化合物及其制造方法
US20190010175A1 (en) Controlled Synthesis of Polymeric Perylene Diimide and Applications Thereof
TW201444852A (zh) 溶液製程用之有機半導體材料以及有機半導體元件
CN106029747B (zh) 倍半硅氧烷复合高分子及其制造方法
CN106823983B (zh) 三维树形共轭化合物-碳纳米管复合物、制备方法及应用
KR20150102861A (ko) 실세스퀴옥산 복합 고분자 및 이의 제조방법
CN102173420B (zh) 一种硅量子点的表面水溶性修饰改性方法
CN107078217A (zh) 包含无机半导体材料和有机粘合剂的半导体组合物
JP2014504022A (ja) ペリレンを基礎とする半導体、並びにそれらの製造及び使用方法
CN109970885A (zh) 一种长共轭咔唑基肟酯光引发剂及其制备方法
CN106062053A (zh) 表面增强透明基板及其制造方法
CN102348728A (zh) 聚合物、使用了该聚合物的有机薄膜和具有其的有机薄膜元件
CN104845052B (zh) 发射波长可控的聚对亚苯基亚乙烯共轭高分子荧光纳米粒子及制备方法
JP2007532748A5 (fr)
CN107456918A (zh) 三维树形共轭化合物-碳纳米管复合物及其应用
Chang et al. Improved chemical resistance of ink‐jet printed micropatterns on glass by using dual‐functional compositions
JP5292771B2 (ja) フラーレン誘導体並びにその溶液及び膜
KR100952218B1 (ko) 식물성 오일을 이용한 광경화성 올리고머 제조방법 및 상기광경화성 올리고머를 이용한 광경화형 잉크
US8754260B2 (en) Method for preparing fluoroacylated arylamine

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17811222

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17811222

Country of ref document: EP

Kind code of ref document: A1