Background of invention
Carbon nanotube can be envisioned as the hexagon grid scraps of paper that are rolled into seamless tube and connect.C-C is represented on every limit of squared paper, and each intersection point is represented carbon atom.
Usually, carbon nanotube generally only has the body of the extension of several atoms for periphery.Carbon nanotube is a fullerene structure hollow and that have straight chain.The length of carbon nanotube might reach millions of times of its molecular scale diameter.Single Walled Carbon Nanotube (SWNTs) and multi-walled carbon nano-tubes (MWNTs) all get the nod.
At present, carbon nanotube has extensively been proposed to be used for many application, because they have the combination of the physicals of the relevant for example intensity of very ideal and uniqueness and weight.Carbon nanotube also demonstrates electroconductibility.See Yakobson, people's such as B.I. Amerincan Scientist, 85, (1997), 324-337; And Dresselhaus, people's such as M.S. Science of Fullerenes and CarbonNanotubes, 1996, San Diego:Academic Press, 902-905 page or leaf.For example, carbon nanotube is than the heat conduction and the good conductivity of copper or gold, and tensile strength is 100 times of steel, and weight only is 1/6 of steel.Carbon nanotube can be made into very little size.For example, carbon nanotube can be made into the size (or approximate hair diameter for the people 1/50000) of approximate dna double spirane structure.
Consider the excellent properties of carbon nanotube, they are very suitable for various uses, from the enhancing that composite wood is examined material that is built into of computer circuits, even the release of arriving medicine.As the result of their performances, carbon nanotube can be used for for example field of microelectronic devices, and this application often requires the thermal conductivity height, size is little and in light weight.A potential application of the carbon nanotube of having approved is their purposes (because carbon nanotube can be good conductor and electron emitter) in the flat pannel display that adopts the electronic field emission technology.The potential application of other that approve comprises electromagnetic shielding, the electromagnetic shielding that for example is used for mobile telephone and laptop computer, the radar of stealth aircraft absorbs, nanoelectronics (comprising the storer in the next generation computer), and as the high-strength light matrix material.In addition, carbon nanotube still is the potential candidate material in electrochemical energy storage system (as lithium ion battery) and the gas storage system field.
Developed the various technology of preparation carbon nanotube, example has the method for the formation carbon nanotube of describing among US 5753088 and the US 5482601, and its content is incorporated herein thinks reference.Three kinds of the most frequently used technology of preparation carbon nanotube are: 1) laser beam evaporation, 2) arc technology and 3) gaseous techniques (HiPco for example
TMThese technology further are discussed method).
" laser evaporation " technology utilizes pulse laser evaporation graphite with the preparation carbon nanotube usually.Laser beam evaporation also by people such as A.G.Rinzler at Appl.Phys.A, describe in 1998,67,29, its content is incorporated herein thinks reference.Laser beam evaporation prepares the carbon nanotube of the about 1.1-1.3 nanometer of diameter (nm) usually.The productive rate of this laser beam evaporation is generally very low, requires the long period to prepare a spot of carbon nanotube.For example, 1 hour general carbon nanotube that produces about 100mg of laser evaporation processing.
The another kind of technology of preparation carbon nanotube is to utilize " electric arc " technology of arc-over synthesizing carbon nanotubes.As an example, can be with the mixture (Ni:Y that has filled metal catalyst and Graphite Powder 99 under helium-atmosphere; C) graphite anode, by arc-over synthesizing single-wall nanotube (SWNTs), people such as C.Journet are at Nature (London), have carried out comprehensive description in 388 (1997), 756.Common this SWNT is made into the closelypacked bundle that diameter is 5-20nm (or " rope ").SWNTs arranges in the two-dimensional and periodic triangular crystal lattice that connects by van der Waals interaction power usually well.The arc technology of preparation carbon nanotube also by C.Journet and P.Bernier at Appl.Phys.A, describe in 67,1, its content is incorporated herein thinks reference.Utilize this arc technology, average carbon nanotube diameter is generally about 1.3-1.5nm, and the triangular crystal lattice parameter is about 1.7nm.The same with laser beam evaporation, the productive rate of electric arc technology of preparing is generally very low, requires the long period to prepare a spot of carbon nanotube.For example, 1 hour electric arc processes generally obtains the carbon nanotube of about 100mg.
Recently, Richard Smalley and he have found another kind of method the colleague of Rice University, i.e. " gas phase " technology, and this method can prepare the carbon nanotube than laser evaporation and the much bigger quantity of electric arc technology of preparing.Gaseous techniques is called HiPc
TMMethod utilizes gas phase catalytic reaction to prepare carbon nanotube.The HiPco method is used general industry gas (carbon monoxide), under the temperature and pressure condition of using always in modern factories, produces the high-purity carbon nano tube of larger amt, and does not have byproduct substantially.The HiPco method, is described in further detail in 1999,313,91 at Chem.Phys.Lett. by people such as P.Nikolaev, and its content is incorporated herein thinks reference.
And with the having a daily output of about 1g/ days of the carbon nanotube of above-mentioned laser evaporation and arc technology preparation, the carbon nanotube day output of HiPco method can reach 1 pound or more.The HiPco technology prepares the much smaller carbon nanotube of diameter for preparing usually than in laser evaporation or the arc technology usually.For example, the nanotube of HiPco technology preparation has the diameter of about 0.7-0.8nm usually.
Overall length (not brachymemma) carbon nanotube owing to its length-to-diameter ratio height, diameter is little, in light weight, intensity is high, electric conductivity and the high basic carbon fiber that is considered to be used for nano structural material of thermal conductivity.See Calvert, P.Nature, 1999,399,210 and Andrews, people's such as R. Appl.Phys.Lett.1999,75,1329, its content is incorporated herein thinks reference.Yet carbon nano-tube material is insoluble in the ordinary organic solvents.See Ebbesen, T.W.Acc.Chem.Res.1998,31,558-556, its content is incorporated herein thinks reference.
The covalency sidewall of carbon nanotube is functionalized to cause the dissolving of carbon nanotube in organic solvent.Should be noted that term " dissolving " and " solubilization " commutative use herein.See Boul, people's such as P.J. Chem.Phys.Lett.1999,310,367 and Georgakilas, people's such as V. J.Am.Chem.Soc.2002,124,760-761, its content is incorporated herein thinks reference.The shortcoming of this method is proper property obvious change because the covalency sidewall is functionalized of carbon nanotube.
Carbon nanotube also can be dissolved in organic solvent and the water by the polymkeric substance parcel.See Dalton, people's such as A.B. J.Phys.Chem.B 2000,104,10012-10016, Star, people's such as A. Angew.Chem.Int.Ed.2001,40,1721-1725, and 0 ' Connell, people's such as M.J. Chem.Phys Lett.2001,342,265-271, its content is incorporated herein thinks reference.Figure 1A-1C represents the example of the polymkeric substance parcel of this carbon nanotube.In the polymkeric substance parcel, polymkeric substance " winding " is around the diameter of carbon nanotube.For example, Fig. 1 represents that polymkeric substance 102A and 102B are wrapped in Single Walled Carbon Nanotube (SWNT) 101 example on every side.Figure 1B represents that polymkeric substance 103A and 103B are wrapped in SWNT 101 example on every side.Fig. 1 C represents that polymkeric substance 104A and 104B are wrapped in SWNT101 example on every side.Should be noted that the polymkeric substance in each example of Figure 1A-1C is all identical, and these legends show that the polymkeric substance parcel type of generation is (twining each carbon nanotube among Figure 1A-1C in a different manner as identical polymkeric substance) at random.A shortcoming of this method is that polymkeric substance is very low because require polymkeric substance that the high deformation states of answering is arranged by the efficient in the minor diameter Single Walled Carbon Nanotube of HiPco method preparation at parcel.For example, this polymkeric substance packaging method only can be with the amount of about 0.1mg/ml with SWNTs
HiPco(i.e. the SWNTs that is prepared by the HiPco method) is dissolved in the organic solvent.SWNTs
HiPcoIt is the unique high purity SWNT material that to make on a large scale at present.
Detailed Description Of The Invention
With reference now to above accompanying drawing, various embodiments of the present invention is described.Embodiment of the present invention provide the novel method of solubilizing nano tube in solvent.Useful is, certain embodiments of the present invention can solubilization in organic solvent, and some embodiment can solubilization in aqueous solvent.This method is based on a discovery, and promptly carbon nano tube surface can be functionalized in non-parcel mode by sense conjugated polymkeric substance.For example, the example molecular model that combines the polymkeric substance of (as non-covalent combination) with carbon nanotube in non-parcel mode is shown in Fig. 2 A-2B.Fig. 2 B is the sectional view of Fig. 2 A of obtaining as indication among Fig. 2 A.As shown in this example, carbon nanotube (in this example more particularly Single Walled Carbon Nanotube) 201 has with it with non-parcel mode bonded polymkeric substance 202.
Polymkeric substance 202 comprises basically along the length direction (rather than diametric(al)) of this carbon nanotube 201 and the main chain 203 of carbon nanotube 201 bonded relative rigidityes.Like this, polymkeric substance 202 combines in non-parcel mode with carbon nanotube 201, and it is favourable because of many reasons, and some reason will here be described more comprehensively.In this example, main chain 203 combine with nanotube 201 (as by with its π-accumulative facies mutual effect), wherein this main chain 203 extends along the length direction of nanotube 201 basically, and about any other part of main chain 203, the extension of any part of main chain 203 all is no more than half of nanotube 201 diameters.For example, main chain 203 has enough rigidity, with respect to the position 206 of small part main chain 203 and nanotube 201 bonded nanotubes 201, the degree of crook of its any part can not make this part surpass the semidiameter (or " equator ") 205 of nanotube 201.The specific rigidity of the different main chains 203 that can implement according to an embodiment of the present invention can be different (for example some enforcement can make the bending of part main chain 203 surpass semidiameter 205, and another part of this main chain is arranged on the position 206 of nanotube 201), but preferably having enough rigidity, this main chain 203 make them not wrap up (promptly surrounding its diameter fully) nanotube 201.Certainly, shown in the example of Fig. 2 A-2B, the part of polymkeric substance 202 (extending 204A and 204B as sense) may extend into all or part of of nanotube 201 diameters, but the main chain 203 of polymkeric substance 202 preferably has enough rigidity, makes around its diameter that is not wrapped in nanotube 201.
Polymkeric substance 202 also comprises the various senses extensions from main chain 203, extends 204A and 204B as sense, and they can contain any various desired functional groups that are used for functionalized carbon nanotubes 201.As further described herein, embodiment of the present invention comprises the functional group in the polymkeric substance 202 that is suitable for solubilization carbon nanotube 201.
Polymkeric substance 202 with non-parcel mode combines (as by π-accumulative facies mutual effect) with carbon nanotube 201 a advantage is, he can make such as the functional group of sense extension 204A and 204B and arrange along main chain 203 in the mode of wanting, with the interval of this functional group of accurate control.In with parcel mode and carbon nanotube bonded polymkeric substance, control is arranged in the relative spacing of the functional group on the polymkeric substance and wants the many of difficulty, because it depends on the parcel of polymkeric substance at interval.By controlling the interval of this functional group along main chain 203, can be between the functional group, between functional group and the carbon nanotube 201, and/or functional group and whether can be exposed between other elements under the functional group/how to interact provides further control.
Another this non-covalent functionalized advantage of carbon nanotube is that it provides significant degree of functionalization can for carbon nano tube surface (sidewall), and still keeps nearly all proper property of nanotube.In other words, as mentioned above, carbon nanotube has very desirable and unique combination of the physicals that relates to for example intensity, weight, electroconductibility etc.Have the ability that the solubilization carbon nanotube keeps nearly all performance of carbon nanotube simultaneously, for example giving, Materials science provides many possibilities.For example, in some applications, carbon nanotube can be by solubilization, and be used to form the ideal performance that provides by nanotube to small part is provided want material (" or material ") composition, below further describe its some example.
Example as the technology that is used for the solubilization carbon nanotube, I adopt the rigidity official to study by conjugated polymers, and described polymkeric substance is polyarylene ethynylene (this paper is also referred to as " 1 ", " 3 ", " 4 "), sees Bunz, U.H.F. Chem.Rev.2000,100,1605-1644 and McQuade, people's such as D.T. J.Am.Chem.Soc.2000,122,12389-12390, its content is incorporated herein thinks reference, and poly-(3-decylthiophene) (this paper is also referred to as " 2 ").Fig. 3 A-3C represents the example polymer architecture of embodiment of the present invention.More specifically, Fig. 3 A represents can be used for non-parcel mode and the non-covalent bonded example of carbon nanotube polyarylene ethynylene (mark " 1 ") polymer architecture.The example polymer architecture of representing among Fig. 3 A comprises sense and extends R
1, R
2, R
3And R
4, they can be used as 1a shown below, 1b, 1c or 1d in implementing as the example of the solubilization carbon nanotube of selecting:
(1a)R
1=R
4=H,R
2=R
3=OC
10H
21
(1b)R
1=R
2=R
3=R
4=F
Fig. 3 B represents can be used for non-parcel mode and another example polyarylene ethynylene of the non-covalent bonded of carbon nanotube (mark " 3 " and this paper are called " 3 ") polymer architecture.In addition, Fig. 3 C represents can be used for non-parcel mode and another example polyarylene ethynylene of the non-covalent bonded of carbon nanotube (mark " 4 " and this paper are called " 4 ") polymer architecture.Although the example polymer architecture shown in Fig. 3 A-3C 1,3 and 4 is polyarylene ethynylene structures, should be understood that the structure that also can adopt other polyarylene ethynylene types according to embodiment of the present invention.
The example polymer architecture of Fig. 3 A-3C can be implemented to be used for to combine with carbon nanotube is non-covalent in non-parcel mode, as the example shown in Fig. 2 A-2B, is used for this carbon nanotube of solubilization.In fact, the example molecular model of Fig. 2 A-2B has illustrated the example of enforcement 1a of the polymkeric substance of above-mentioned Fig. 3 A, and 1a is implemented in expression more specifically
N=15-SWNT
(6,6)The example of title complex (being armchair SWNT), wherein n is repeat number.Should be appreciated that, the present invention is not limited in the functional group (or functional group of polymer architecture 3 and 4) of above-mentioned 1a, 1b, 1c and the 1d of solubilization carbon nanotube, but can adopt any this class functional group of the solubilization carbon nanotube of known now or later exploitation according to embodiment of the present invention.Preferably, the solubilization functional group that comprises in the polymkeric substance does not change the proper property of carbon nanotube substantially.
Fig. 4 represents to realize another example with non-parcel mode and the non-covalent bonded polymer architecture of carbon nanotube.More specifically, Fig. 4 represents the exemplary construction of cephalocaudal poly-(3-decylthiophene) (mark " 2 "), the high rule district (highlyregioregular) that can implement in certain embodiments of the invention.
With former work contrast, see Dalton, Star and O ' Connell, M.J. etc., above-mentioned main chain 1,2,3 and 4 be an inflexible, can not wrap up around SWNTs, and main polymer chain is parallel π-accumulation with main interaction between nanotube surface.And example main chain 5-18 described below also is an inflexible, makes them around nanotube parcel, and this main polymer chain is parallel π-accumulation with main interaction between nanotube surface.Covalently bound one type of parallel π-accumulation right and wrong.See Chen, people's such as R.J. J.Am.Chem.Soc., 2001,123,3838-3839, its content is incorporated herein thinks reference.Technology disclosed herein utilize this polymkeric substance make various types of carbon nanotubes dissolvings (or " solubilization ") at organic solvent (as CHCl
3, chlorobenzene etc.) in, its representative does not have polymkeric substance to wrap up first example of solubilization carbon nanotube by π-accumulations.
As an example, by with 1 (as 1a, 1b, 1c or 1d), 2,3 or 4 mixed, in acutely shaking and/or bathing behind the sonication, be easy to SWNTs added and be dissolved in CHCl
3In.Solubilization SWNTs
HiPcoThe minimum weight that (i.e. the SWNTs for preparing by the HiPco technology) requires is than (WR
Initially) 1: SWNTs
HiPco, 2: SWNTs
HiPco, 3: SWNTs
HiPcoWith 4: SWNTs
HiPcoBe about 0.4; SWNTs
HiPcoAt CHCl
3In peak concentration be about 5mg/ml for 1d, it represents SWNTs
HiPcoBy non-covalent functionalized highest solubility in organic solvent.For example, 13.6mg SWNTs
HiPcoCan in the presence of the 1a of 5.4mg, be dissolved in 6.8ml CHCl
3In; 20.4mg SWNTs
HiPcoCan in the presence of the 1d of 20.4mg, be dissolved in 4.0ml CHCl
3In.SWNTs
Laser(i.e. the SWNTs for preparing by laser technology) and SWNTs
Electric arcThe peak concentration of (i.e. the SWNTs for preparing by arc technology) is about 0.5mg/ml for 1a.The solubleness of SWNTs can further improve by length and the component of optimizing polymer lateral chain.For example, long side chain and/or side chain with branched structure can further improve the solubleness of SWNTs.
As another example,, be easy to SWNTs is dissolved in the deionized water by mixed behind the sonication in bathing with 4.For example, 13.7mg SWNTs
HiPcoCan 13.7mg 4 in the presence of be dissolved in the 6.9ml deionized water.
Synthetic and characterize new polymkeric substance (1a-1, n according to known method
On average=19.5; 1a-2, n
On average=13; 1b, n
On average=19; 1c, n
On average=19; 1d).See Bunz, U.H.F.CHem.Rev.2000,100,1605-1644, its content is incorporated herein thinks reference.Adopt three types SWNTs:1 in the research) the HiPco-SWNTs (" SWNTs that purifies
HiPco", from CarbonNanotechnologies, Inc.); The SWNTs (" SWNTs of the laser growth of 2) purifying
Laser"); With 3) the SWNTs (" SWNTs of the electric arc growth of purifying
Electric arc").As 1a-SWNTs
HiPcoPreparation method's example of title complex: 14.7mg SWNTs
HiPcoAt 29.4ml CHCl
3In sonication 30 minutes (" min "), obtain the unsettled suspension of visible insoluble solid.Add 14.7mg 1a then, simply by acutely shaking, most visible insoluble solids solubilized that becomes.With the further sonication 10-30min of gained solution, obtain all detecting after 10 days black stabilizing solution less than solid precipitation.This black that obtains with the detect by an unaided eye no scattering and shelve (as above 10 days) for a long time and do not produce precipitation of undersaturated carbon nano-tube solution.This product is collected by PTFE film filter (0.2-0.8 μ m aperture), uses CHCl
3Flushing and vacuum-drying at room temperature obtain the black solid film (bucky paper) that 20.6mg supports oneself.
In my research, for 2-SWNTs
HiPco, 1c-SWNTs
HiPco, 1b-SWNTs
HiPco, 1d-SWNTs
HiPco, 3-SWNTs
HiPco, 1a-SWNTs
LaserAnd 1a-SWNTs
Electric arcMethod and above-mentioned for 1a-SWNTs
HiPcoMethod similar.Zhi Bei SWNTs like this
HiPcoAnd CVD) Sheng Chang multi-walled carbon nano-tubes (MWNTs) also can add by similar method and is dissolved in CHCl
3In.Yet, Zhi Bei SWNTs like this
Electric arcFormed unsettled suspension with similar approach, perhaps be because amorphous carbon be coated in hindered on the nanotube 1 and nanotube surface between effectively π-π interact.
PTFE membrane filtration and (CHCl
3Cleaning step is used to remove free 1a.Increase the weight ratio (WR in the final product according to weight
Finally) 1a: SWNTs
HiPcoBe estimated as about 0.38-0.40, with WR
InitiallyIrrelevant.For example, at three 1a: SWNTs
HiPcoWP data in the reaction are as follows: 1) WR
Initially=1.00, WR
Finally=0.40; 2) WR
Initially=0.40, WR
Finally=0.38; 3) WR
Initially=0.40, WR
Finally=0.39.Although it is coarse that this estimation still shows, it effectively illustrates, 1 can with carbon nanotube at CHCl
3In form stable and bonded title complex irreversibly, rather than simple mixture.
The preferred embodiment of the invention provides the solubilization carbon nanotube, has kept the polymkeric substance of nearly all proper property of nanotube simultaneously.For example, Fig. 5 A represents to illustrate SWNTs
HiPcoThe film visible light of (not having bonded polymkeric substance with it) and near infrared (IR) spectrographic graphic representation.Fig. 5 B represents to illustrate 1a-SWNTs
HiPcoThe film visible light and the graphic representation of near infrared spectrum.According to film visible light and nearly IR spectrum, 1a-SWNTs
HiPcoThe band structure of (Fig. 5 B's) and original SWNTs
HiPcoThe band structure of (Fig. 5 A's) is closely similar, shows SWNTs
HiPcoElectronic structure remain untouched substantially when when polymkeric substance, cooperating.Based on absorption spectrum and Raman spectrum, can think 1a-SWNTs
HiPcoIn charge transfer not obvious.Should be noted that at 1a-SWNTs
HiPcoIn (Fig. 5 B's) spectrum, the SWNTs between very wide signal covering 3.5-2eV is arranged
HiPco(Fig. 5 A's) signal, it may be the minimum energy absorption generation by 1a in the nanotube title complex.
With by pure SWNTs
HiPco(tensile strength=9.74MPa; The bucky paper of Young's modulus=0.26GPa) make relatively, by 1-SWNTs
HiPcoBucky paper (tensile strength=28.3MPa that title complex is made; Young's modulus=4.5GPa) shows the mechanical property of obvious improvement.These two kinds of bucky paper all by the membrane filtering method under the identical room temperature (without any high temperature annealing) preparation, are convenient to compare better, and this shows that 1 can improve the binding property between nanotube by more effective π-π interaction.Equally, the bucky paper that obtains is with low concentration (1a-SWNTs
HiPcoAt CHCl
3In be about 0.1-0.2mg/ml) be dissolved in CHCl slowlyer
3In.For the application that requires high concentrations of nanotubes (for example polymer complex), recommend to use preparation on the spot and the CHCl of not filtering 1-SWNTs (W=0.4)
3Solution.
The embodiment of selecting according to the present invention, various other solubilities functional polymers with pi-conjugated backbone structure also are used in solubilization carbon nanotube in the organic solvent.Some this main polymer chain structure is as follows, and (R represents any organo-functional group; Ar represents any pi-conjugated structure), as structure 5-18:
In above main chain 5-18, n is preferably more than or equal to 2, and R represents any organo-functional group, as R=OC
10H
21, R=C
10H
21, or other functional groups of enumerating of solubilizing nano tube described herein.Should be realized that example main chain 5-15 is the polyarylene ethynylene, main chain 16 is a polyphenylene, and main chain 17 is a polypyrrole, and main chain 18 is a Polythiophene.
The 1-SWNTs of preferred embodiment
HiPcoSolution can with other polymers soln uniform mixing such as polycarbonate and polystyrene.Can prepare uniform nanotube-polycarbonate and nanotube-poly styrene composite material by removing organic solvent.
As an example, with the chloroformic solution (125mg/ml) and the 2.89ml1a-SWNTs of 0.6ml poly bisphenol carbonic ether
HiPcoChloroformic solution (1.3mg/ml SWNTs
HiPco) uniform mixing.Form the uniform SWNTs/ poly bisphenol carbonic ether matrix material (SWNTs of 5wt% after removing chloroform solvent
HiPco).By changing ratio 1a-SWNTs
HiPco: the poly bisphenol carbonic ether is easy to make the different SWNTs/ poly bisphenol carbonic ether matrix material of SWNTs loading level.
Solubility 1a-SWNTs
HiPcoTitle complex has significantly improved the mechanical property of commercial polymer.For example, the tensile strength of pure poly bisphenol carbonic ether and breaking strain are respectively 26MPa and 1.23%; The SWNTs of 3.8wt%
HiPcoFilling causes the tensile strength (43.7MPa) and the breaking strain (19.1%) of poly bisphenol carbonic ether (average Mw is about 64000) to improve 68% and 1800% respectively.
Fig. 6 A-6D, 7A-7B and 8A-8C represent transmission electron microscope (TEM) image, and Fig. 9 represents field emission scanning electron microscope (SEM) image, below further describes.More specifically, Fig. 6 A represents 1-SWNTs
LaserThe TEM image, Fig. 6 B represents 1-SWNTs
Electric arcThe TEM image, and Fig. 6 C and 6D represent 1-SWNTs
HiPcoThe TEM image.As a reference, the reticle of representing among Fig. 6 A-6D (scale bar) is 100nm.
Fig. 7 A and 7B represent 1a-SWNTs
LaserHigh resolving power TEM image (120kV is with a freshly prepd 1a-SWNTs
LaserThe HoleyCarbon 400 order TEM grid that chlorobenzene solution (about 0.05mg/ml) places with Kimwipes brush contacts on (SPI Supplies removes the Formvar coating).Blot solvent very soon with brush, prevent that nanotube is coalescent).As a reference, the reticle of representing among Fig. 7 A-7B is 5nm.
Fig. 8 A-8C represents 1a-SWNTs
Electric arcHigh resolving power TEM image (120kV is with a freshly prepd 1a-SWNTs
Electric arcThe HoleyCarbon 400 order TEM grid that chlorobenzene solution (about 0.05mg/ml) places with Kimwipes brush contacts on (SPI Supplies removes the Formvar coating).Blot solvent very soon with brush, prevent that nanotube is coalescent).As a reference, the reticle of representing among Fig. 8 A-8C is 5nm.
Fig. 9 represents Bucky paper (1a-SWNTs
HiPco) the field emission SEM image (1.00kV) of torn edges, show that most of sample is the SWNT nano belt.The TEM image shows, 1a-SWNTs
LaserAnd 1a-SWNTs
Electric arcIn most of SWNTs be marline (ropes) (2-6nm sees Fig. 6 A, 6B, 7A, 7B and 8A-8C), and 1a-SWNTs
HiPcoIn most of SWNTs be the nano belt lamination member (assemblies) (seeing Fig. 6 C, 6D and Fig. 9) of marline.The observation of the SWNTs nano belt of twisting on the TEM grid surface of representing among Fig. 6 D is shown the soundness of this two dimension (2D) lamination member and further confirmed and along the π between the main polymer chain of nanotube length direction orientation-accumulative facies mutual effect.This nano belt shows soundness, because if should two dimension lamination member not firm, just is easy to be decomposed into marline on TEM grid surface.For example have a large amount of and/or ionic functional group's 1 by adopting, should be able to avoid this 2D lamination member and obtain little rope form and/or independent SWNTs in the side chain end
HiPco
With by pure SWNTs
HipcoBucky paper (tensile strength=the 9.7MPa that makes; Young's modulus=0.26GPa) relatively, by 1-SWNTs
HiPcoBucky paper (tensile strength=28.3MPa that title complex is made; Young's modulus=4.5GPa) shows the mechanical property of obvious improvement quantitatively.These two kinds of bucky paper all by the membrane filtering method under the identical room temperature (without any high temperature annealing) preparation, are convenient to compare better.
Should be realized that from above-mentioned viewpoint, embodiment of the present invention provide can be with non-parcel mode and the non-covalent bonded molecular structure of nanotube (as carbon nanotube), and this molecular structure can contain the one or more functional groups that are useful on solubilization and this molecular structure bonded nanotube.Preferably, this molecular structure and nanotube form non covalent bond, yet in some instances, molecular structure also can be with those of non-parcel mode and nanotube formation covalent linkage.
The solubilization of nanotube makes it can be used for strengthening and comprise for example performance of the various compositions of the material of plastics.Insoluble nanotube can not be dispersed in commercial plastics and the tackiness agent; Therefore by adding polymer composites that insoluble nanotube makes to the improvement of plastics machinery performance very little (Ajayah, people's such as P.M. Adv.Mater.2000,12,750; Schadler, people's such as L.S. Appl.Phys.Lett.1998,73,3842).On the contrary, the solubility nanotube can significantly improve for example mechanical property of plastics.For example, the tensile strength of pure poly bisphenol carbonic ether and breaking strain are respectively 26MPa and 1.23%; The SWNTs of 3.8wt%
HiPcoFilling causes the tensile strength (43.7MPa) and the breaking strain (19.1%) of poly bisphenol carbonic ether (average Mw is about 64000) to improve 68% and 1800% respectively.
Though above-mentioned various example has all been described the solubilization carbon nanotube, Single Walled Carbon Nanotube more specifically, embodiment of the present invention are not limited in the application on the carbon nanotube.Nanotube can be by such as carbon, boron nitride, and the various materials of their compound form.Nanotube can be single-walled nanotube or many walls nanotube.Like this, though example described herein is to be used for the solubilization carbon nanotube, but certain embodiments of the present invention also can be used for the nanotube of the various other types of solubilization, include but not limited to multi-walled carbon nano-tubes (MWNTs), boron nitride nano-tube, and their mixture.Therefore, term used herein " nanotube " is not limited only to carbon nanotube.On the contrary, term " nanotube " is extensive use of at this paper, unless otherwise defined, often comprises now known or later any kind nanotube with exploitation.
Although the present invention and advantage thereof are described in detail, should be realized that, under the prerequisite that does not break away from the spirit and scope of the present invention that define by appended claims, can do various variations, substitute and change.And the specific embodiments of the scope of the present invention method, machinery, manufacturing, composition of matter, means, method and the step that are not limited to describe in the specification sheets.Those of ordinary skills are easy to understand from content of the present invention, now existed or will develop later on, finish with the corresponding essentially identical function of embodiment described herein or realize essentially identical result's technology, machinery, manufacturing, composition of matter, means, method or step, all can be utilized according to the present invention.Therefore appended claims are intended to this technology, machinery, manufacturing, material composition, means, method or step are included in its scope.