WO2008140533A2

WO2008140533A2 - Processes for making composites and blends of loose single-walled carbon nanotube ropes (swnt-rs) and other carbon nanotube ropes with acid soluble polymers and other materials, and products made therefrom

Info

Publication number: WO2008140533A2
Application number: PCT/US2007/077026
Authority: WO
Inventors: Wen-Fang Hwang; Zheyi Chen; James M. Tour
Original assignee: William Marsh Rice University
Priority date: 2006-08-29
Filing date: 2007-08-28
Publication date: 2008-11-20
Also published as: WO2008140533A3

Abstract

Processes to make these composite materials or blends, and their shaped articles such as fibers, films and 3-D parts include mixing an acid intercalated SWNT-Rs with an acid soluble polymer and subjecting the resultant mixture to shear stresses. Composites and blends include loose single-walled carbon nanotube ropes (SWNT-Rs) and other acid-intercalatable carbon nanotube ropes with polymers such as aliphatic polyamides (nylon), aromatic polyamides (such as poly-p-phenylene terephthalamide, PPTA), or heterocyclic aromatic polymers (such as poly-p-phenylenebisbenzoxazole, PBO), or other materials which are soluble in common acidic media. Products such as fibers, films, and 3-dimensional articles are made from these materials.

Description

PROCESSES FOR MAKING COMPOSITES AND BLENDS OF LOOSE

SINGLE- WALLED CARBON NANOTUBE ROPES (SWNT-RS) AND OTHER

CARBON NANOTUBE ROPES WITH ACID SOLUBLE POLYMERS AND

OTHER MATERIALS, AND PRODUCTS MADE THEREFROM

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application number 60/840,892, filed on August 29, 2006 which is incorporated herein by reference in its entirety.

FEDERALLY-SPONSORED RESEARCH

[0002] This disclosure was made, in part, with support from the Air Force Office of Scientific Research, Grant No. FA9550-05-1-0152.

DESCRIPTION OF THE FIGURES

[0003] The foregoing and other features and aspects of the present disclosure will be best understood with reference to the following detailed description of a specific embodiment of the disclosure, when read in conjunction with the accompanying drawings, wherein:

Figure Ia shows a SEM image of powdered single-wall carbon nanotube ropes (SWNT- Rs)/Nylon 6,6 composite before injection molding.

Figure Ib shows a SEM image of neat nylon 6,6 after injection molding.

Figure Ic shows a SEM image of a nylon 6,6 composite with single- wall carbon nanotube ropes (SWNT-Rs) after injection molding.

Figure 2a shows a mixture of PPTA in sulfuric acid and loose SWNT-Rs in oleum without stirring.

Figure 2b shows a mixture of PPTA in sulfuric acid and loose SWNT-Rs in oleum with stirring; the image shows stir-opalescence typical of a liquid crystalline solution of PPTA.

Figure 3 a shows an optical microscope image of SWNT-Rs/PPTA composite solution under crossed polarization conditions. Figure 3b shows another optical microscope image of SWNT-Rs/PPTA composite solution under crossed polar conditions.

DETAILED DESCRIPTION

[0004] Due to strong van der Waals attractions, individual single-wall carbon nanotubes (SWNTs) tend to aggregate into 10-20 run diameter "primordial" ropes; and these fine, long (up to hundreds of microns in length) ropes tend to entangle into tight networks during the HiP co (J. Vac. Sci. Technol. 2001, 19, 1880-1805) production process. This, coupled with their limited solubility in common solvents, renders them difficult to process into functional articles such as fibers or films, or mixed with other materials such as polymers and other non-polymeric materials to from composites or polymer blends. Fortunately, super acids (for example > 100% sulfuric acids with excess SO₃) are known to intercalate in between individual SWNTs inside the above-described SWNT ropes [Science 305, 1447 (2004)]. Embodiments disclosed herein exploit this acid-interaction phenomena uniquely associated with SWNTs, especially SWNTs with pristine side-walls. These acid-intercalated SWNT ropes become flexible, processible, orientable and can be disentangled as demonstrated in Applicant's own work [JACS, 2006, 128, 10568-10571] into loose SWNT ropes (SWNT-Rs). Also, other loose carbon nanotube ropes can be generated as long as these carbon nanotubes can be intercalated with super acids or other appropriate media.

[0005] As disclosed herein, when suspended in super acids, these loose, long (several micrometers or more in length) and fine (tens to hundreds of nanometers in diameter) SWNT ropes, intercalated with super acids, become flexible, alignable, processible and can be mixed with and dispersed in acid-soluble polymers such as Nylon, poly-p-phenylene terephthalamide (PPTA), poly-p-phenylenebisbenzoxazole (PBO), or other acid-soluble materials; subsequently, these SWNT-Rs/polymer mixtures in acid media can then be processed into uniaxially aligned fibers, planar isotropic films, or isotropic 3-D articles by conventional means. Since these SWNT-Rs have high aspect ratio (length/diameter ratio), the SWNT-Rs/polymer composites and blends should have desirable physical/mechanical properties and other superior properties afforded by SWNTs while retaining the processibility and moldability of the polymers.

[0006] The present disclosure also provides composites and blends including loose single- walled carbon nanotube ropes (SWNT-Rs) and other acid-intercalatable carbon nanotube ropes with polymers such as aliphatic polyamides (nylon), aromatic polyamides (such as poly-p- phenylene terephthalamide, PPTA), or heterocyclic aromatic polymers (such as poly-p- phenylenebisbenzoxazole, PBO), aromatic polyester, or other materials which are soluble in common acidic media; or any combination thereof; and the products such as fibers, films, and 3 -dimensional articles made from such materials. The present disclosure also relates to processes to make these new composite materials or blends, and their shaped articles such as fibers, films and 3-D parts.

[0007] In the further description that follows, specific details are set forth such as specific quantities, sizes, etc. to provide a thorough understanding of the present disclosure. However, it will be obvious to those skilled in the art that the present disclosure may be practiced without such specific details. In many cases, details concerning such considerations and the like have been omitted inasmuch as such details are not necessary to obtain a complete understanding of the present disclosure and are within the skills of persons of ordinary skill in the relevant art.

[0008] Embodiments disclosed herein relate to a method for generating highly dispersed SWNT ropes in polymer matrices. Broadly, the method involves high shear mixing of single- wall carbon nanotube ropes (SWNT-Rs) in a superacid medium to form loose, acid intercalated SWNT-Rs. The high shear mixing of acid intercalated SWNT-Rs generates loose individual SWNT-Rs. Next, one places an acid soluble polymer in the same acid (or a compatible acid) as that used to produce the SWNT-Rs, to form a polymer solution. In some embodiments, the combining of the SWNT-Rs and the polymer solution may be performed by mixing the acid intercalated SWNT-Rs with the polymer solution using a high sheer mixer. In other embodiments, however, the solution of loose, acid-intercalated SWNT-Rs is mixed with the polymer solution by simple stirring. In both cases, a SWNT-Rs/polymer composite solution is formed. In some embodiments where the polymers are thermoplastics (such as aliphatic polyamides or aliphatic polyesters), the composite solution is then poured into an appropriate coagulant solvent (in most cases, this coagulation solvent is one in which the acid is soluble but the SWNT-Rs and polymer(s) are not) to precipitate the SWNT-Rs/polymer composite; these composite solids (in the forms of powder or pulps) are then separated from the coagulation solvent by filtration, and the resulting solids are washed and dried before being shaped into fibers, films or 3-D parts. In other embodiments where the polymers are high temperature polymers (defined as a polymer that does not have a glassy transition temperature and melting point) such as PBO, PPTA, or other aromatic polymers, the resultant composite solution will be subjected to direct shaping processes to form the final composite part.

[0009] Shaping: In some embodiments where the polymers are high temperature polymers, the shaping of the SWNT-Rs/polymer composite solution may be accomplished by extruding the composite solution, for example. The extrusion may be through a spinnerette or through a film die, for example. The shaped composite is then subjected to coagulation, washing, drying, and post treatment processes, typical of fiber and film formations. In other embodiments where the polymers are thermoplastics, the dried SWNT-Rs/polymer composite can be shaped by a casting and/or injecting process into a mold. Shaping in a mold may involve the use of elevated temperatures and/or pressures. The dried SWNT-Rs/polymer composite can also be shaped using conventional melt-spinning or melt-casting process into fibers or films.

[0010] Solvent selection: In some embodiments, the superacid medium that the SWNT-Rs are mixed with includes approximately 100% sulfuric acid with an excess of SO₃ ranging from about 1% by weight to about 30% by weight (also called fuming sulfuric acid, or oleum). Solvents for the polymer matrix may include, for example, fuming sulfuric acid (containing from about 1% by weight to about 30% by weight SO₃), methanesulfonic acid, trifluoromethanesulfonic acid, polyphosphoric acid, dimethylformamide (DMF), and JV- methylpyrrolidinone (NMP).

[0011] Solvent removal: After shape forming, the solvent may be removed from the composite mixture. This may be accomplished by, for example, evaporation. Evaporation may be accomplished by any combination of heating and subjecting the article to reduced pressure. The solvent may also be removed by direct coagulation. In alternate embodiments the solvent may be substantially removed prior to shaping. The subsequent shaping of the composite may then be accomplished by, for example, applying heat and/or pressure.

[0012] Polymer matrix: The polymer may be any acid soluble polymer matrix and includes, for example, nylon, PPTA, PBO, and combinations thereof; optionally, the polymer matrix could also be one that is soluble DMF and/or NMP. The polymer may be present in the composite in the amount ranging from about 80 % by weight to about 99.99% by weight (with the remainder being SWNT-Rs and other additives); in another embodiment, the polymer amount in the composite ranges from about 95% to about 99.99% by weight (with the remainder being SWNT- Rs and other additives).

[0013] The present disclosure seeks to reinforce polymers or other materials with loose SWNT-Rs, thus forming composites or blends with superior properties.

[0014] In some embodiments, the present disclosure provides new composites and blends comprising loose single- walled carbon nanotubes ropes (SWNT-Rs) and other acid-intercalatable carbon nanotube ropes with polymers such as aliphatic polyamides (nylon), aromatic polyamides (PPTA), or heterocyclic aromatic polymers (PBO), or other materials which are soluble in common acidic media; or any combination thereof and other materials; and the products such as fibers, films, and 3 -dimensional articles made from such materials.

[0015] In some embodiments, the present disclosure is directed toward processes to make these new composite materials or blends, and their shaped articles such as fibers, films and 3-D parts.

[0016] In some embodiments, processes can generally involve the following steps: (1) Dissolve the polymers in strong acids such as, but not limited to, super sulfuric acids (e.g., fuming sulfuric acid), methanesulfonic acid, trifluoromethanesulfonic aicd, polyphosphoric acid, aprotic solvents (such as N-methyl-2-pyrrolidone (NMP) or dimethylformamide (DMF)), and combinations thereof, at appropriate concentration; in principle, the concentration should be as high as possible; in the case of lyotropic polymers such as PPTA and PBO, the concentration of the solution should be high enough that the solution shows liquid crystalline behavior; (2) Disperse the disentangled SWNT ropes or loose SWNT ropes produced by the carpet growth method or other production methods in super sulfuric acids until a homogeneous suspension is achieved, with concentration as high as possible; alternatively, acid intercalated SWNT-Rs may be added to dry polymer pulps; and (3) Mix appropriate amounts of the above polymer solution (or dry pulp) and SWNT suspension, until a homogeneous mixture is obtained, to make between 0.001/99.999 to 99.5/0.5 wt/wt% SWNT-Rs/polymer composites. In some embodiments, the above said SWNT-Rs/polymer solution is then shaped by being extruded through a spinneret, or a film die, or being cast into a mold; and then the solvent of the shaped solution is removed by evaporation or direct coagulation, at appropriate conditions using appropriate apparatus, or the combination thereof. In other embodiments, the solvent of the SWNT-Rs/polymer solution is removed first and then shaped by heat and/or pressure. In some embodiments, the shaped articles in which the polymers are thermoplastic or high temperature polymers are then dried and heat treated at elevated temperature. In other embodiments, the shaped articles are converted to the final material through appropriate conditions and high temperature treatments.

[0017] Disclosed herein is a method of incorporating loose SWNT ropes (SWNT-Rs in which SWNTs have pristine side-walls), produced, for example, by a disentanglement process or directly from a carpet growth method (See Xu et al., "Vertical Array Growth of Small Diameter Single-Walled Carbon Nanotubes," J. Am. Chem. Soc, 128, pp. 6560-6561 (2006)), or SWNTs produced by other methods, or other carbon nanotube ropes capable of being intercalated with super acid, into polymers or other materials which are soluble in strong acids or aprotic solvents, or other suitable solvents. One distinguishing feature of the method is the use of SWNT ropes which are dispersible in the strong acids.

[0018] The present disclosure provides a process of incorporating the SWNT ropes into polymers such as nylon, PPTA, PBO and other acid-soluble polymers forming a SWNT- Rs/polymer composite which has physical/mechanical properties that are superior to that of the polymer host while maintaining the ease of processibility of the host polymers. Specifically, embodiments disclosed herein incorporate between 0.001 wt% to 50 wt% or more of SWNT-Rs into the corresponding 99.999 wt% to 50 wt% of polymers. In some embodiments, the process can involve the following steps: (1) Dissolve the polymers in strong acids such as, but not limited to, super sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, polyphosphoric acid, or aprotic solvents such as NMP, DMF, or their combination thereof, at appropriate concentration; in principle, the concentration should be as high as possible; in case of the lyotropic polymers such as PPTA, PBO, the concentration of the solution should be high enough that the solution shows liquid crystalline behavior; (2) Disperse the disentangled SWNT ropes or loose SWNT ropes produced by any desirable method (including the carpet growth method, for example) in super sulfuric acids until a homogeneous suspension is achieved, producing SWNT-Rs, with concentration as high as possible; (3) Dispersing appropriate amounts of the SWNT-Rs in super sulfuric acids into the polymer solution to form a homogeneous solution where the SWNT-Rs are homogeneously dispersed in these polymers; (4) Shaping the above-mentioned solution by extrusion of the solution through a spinneret or film die; (5) coagulating the shaped solution in a coagulation bath of appropriate compositions with optimum coagulation rate or consolidating the shaped solution in an forced-air oven or an vacuum oven at appropriate temperature through the evaporation of the solvent; generally, there is an air-gap of various length between the exit of the spinneret and the top surface of the coagulation bath and, generally, the speed of the take-up roll (drum) is higher than the linear extrusion rate of the polymer solution, the ratio between the take-up speed and the extrusion rate is called the spin- draw-ratio, which is preferred to be as high as possible for highest possible axial orientation of the composite fibers or films; and (6) providing a series of post-treatments of the shaped articles such as (i) wet-drawing to further the axial orientation of the fibers or films, (ii) washing and drying to get rid of the residual solvent, (iii) annealing, heat treating, or pressure molding to further enhance the properties of the shaped articles.

[0019] In other embodiments, the present disclosure provides a process of incorporating SWNT-Rs into thermoplastic polymers such as, but not limited to, aliphatic polyamides, and to shaping them into 3-D articles. Specifically, embodiments disclosed herein provide a method of incorporating between 0.001 wt% to 50 wt% or more of SWNT-Rs into the corresponding 99.999 wt% to 50 wt% of polymers. The process can generally involve the following steps: (1) Dissolve the polymers in strong acids such as, but not limited to, super sulfuric acid, methane sulfonic acid, trifluoromethanesulfonic acid, polyphosphoric acid, aprotic solvents such as NMP, DMF, or their combination thereof, at appropriate concentration; in principle, the concentration should be as high as possible; (2) Disperse the disentangled SWNT ropes or loose SWNT ropes produced by the carpet growth method in super sulfuric acids till an homogeneous suspension is achieved, with concentration as high as possible; (3) Mix appropriate amount of the above polymer solution and SWNT-Rs suspension until a homogeneous mixture is obtained; (4) The solvent of the solution is then removed by evaporation or direct coagulation, at appropriate conditions using appropriate apparatus(es), or the combination thereof; (5) The resultant SWNT- Rs/polymer is then washed and dried to remove any residual solvents and acids; (6) The dried SWNT-Rs/polymers is then shaped into 3-D articles by heat and pressure using conventional processes such as injection molding or compression molding.

[0020] Applications of the materials so made include use as advanced resins for advanced fiber composites, and use as next-generation advanced fibers and films. [0021] The processes described herein provide a new, scalable process where the SWNT-Rs can be dispersed efficiently in polymer matrices thus forming composites with unprecedented properties.

EXAMPLES

[0022] The following examples are included to demonstrate particular embodiments of the present disclosure. It should be appreciated by those of skill in the art that the methods disclosed in the examples that follow merely represent exemplary embodiments of the present disclosure. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments described and still obtain a like or similar result without departing from the spirit and scope of the present disclosure.

[0023] These Examples serve to illustrate the process of making SWNT-Rs/polymer composites and Composite Fibers, in accordance with embodiments of the disclosed herein.

[0024] Example 1: 5/95 wt/wt% SWNT-Rs/Nylon 6.6 composite

1. Dissolve 4.75 g Nylon 6,6 in 75 mL methane sulfonic acid (MSA).

2. Prepare 0.43% SWNT-Rs/oleum solution by the disentanglement process (A multi-step process consisting of (a) soaking of SWNTs (0.43 wt% concentration) in oleum (20% SO₃) overnight so that the intercalation of acid into the tightly entangled network of SWNTs will loosen the ropes; (b) use of an immersion blender such as a rotor/stator operating at high speed (10000 rpm) for up to 72 h to disentangle the network; and optionally (c) precipitation and washing of the disentangled SWNTs to rid them of residual acid; and finally, (d) vacuum drying. These disentangled SWNTs can be readily intercalated with fuming sulfuric acid). The SWNTs

used were produced using the HiPco process (United States Patent 7,204,970 Smalley, et al. April 17, 2007).

3. 30 mL of the SWNT-Rs solution in oleum from step 2b (250 mg disentangled SWNTs in 30 mL oleum) was diluted to 98% H₂SO₄ by mixing with 43.8 mL of 96% H₂SO₄ (to prevent the degradation of the nylon 6,6 in the solution of step 1 by the super sulfuric acid). 4. The nylon MSA solution prepared in step 1 was mixed with the SWNT-Rs solution prepared in step 3 using high speed homogenization at 10,000 rpm for 1 min.

5. The homogenized product from step 4 was coagulated in icy deionized (DI) water (5 parts water: 1 part mixed solution) by pouring the homogenized product from step 4 carefully into the icy DI water, followed by high speed homogenization at 10,000 rpm for 5 min.

6. The suspension produced in step 5 was filtered through a 5 μm polycarbonate filter membrane using a vacuum filter apparatus.

7. The solid slush remaining on the filter from step 6 was washed with DI water until the aqueous filtrate was neutral. The solid product remaining on the filter was washed with methanol several times (to drive the water out of the coagulated product) and ethyl ether several times (to drive the methanol out of the coagulated project).

8. The washed, coagulated product from step 7 was stirred in a beaker on a hot plate (~50 °C) to make a fine powder. This powder was visualized under SEM as shown in Figurela.

9. The product from step 8 was vacuum dried at 50 °C overnight.

[0025] For comparison purposes, a 5/95 wt/wt% ultra-short SWNTs (US-SWNTs)/Nylon 6,6 composite was made by:

1 Dissolving 4.75 g Nylon 6,6 in 75 mL MSA.

2 Dissolving 250 mg US-SWNTs in 75 mL MSA.

3 Mixing the solution from step 1 with the solution from step 2 using high sheer homogenization at 10000 rpm for 1 min.

4. Coagulating the product from step 3 in icy DI water by carefully pouring the homogenized mixture into the icy DI water, followed by high sheer homogenization at 10000 rpm for 5 min.

5. Filtering the coagulated product from step 4 through a 5 μm polycarbonate filter membrane using a vacuum filter apparatus, and washing the solid remaining on the filter with water until the aqueous filtrate was neutral, followed by washing the solid remaining on the filter with ethyl ether to drive out the water. 6. The coagulated, washed product from step 5 was vacuum dried at 50 ⁰C overnight.

[0026] Both types of SWNT/Nylon composite parts were made by injection molding at 300 C, with mold temperature at 70 ⁰C. The modulus results determined by using a dynamic mechanical analyzer (DMA) are shown in Table 1 below.

Table 1

[0027] The superior performance of the SWNT-Rs/Nylon over neat nylon is readily apparent.

[0028] Also, Figures lb-c show the morphological difference between the three types of nylons. The SWNT-Rs/Nylon 6,6 composite shows the distinct rope structure of SWNT-Rs while US-SWNTs/Nylon and neat nylon do not, as expected.

[0029] Example 2. 20/80 wt/wt% SWNT-Rs/Amorphous Nylon Composites 1 Dissolve 4 g amorphous Nylon in aprotic solvent (150 mL NMP)

2. Dilute the acid in the previously prepared SWNT-Rs/oleum solution to 98% by adding 66 mL 96% H₂SO₄ to the suspension of 1 g SWNT-Rs in 188 mL 110% H₂SO₄.

3. The solution prepared in step 1 was mixed with the solution prepared in step 2 using high sheer homogenization at 10000 rpm for 1 min.

4. The homogenized product from step 3 was coagulated by pouring the mixture into 1200 mL icy Nanopure water followed by high sheering homogenization at 10000 rpm for 5 min.

5. The coagulated product from step 4 was filtered through a 5 mm polycarbonate filter using a vacuum filter apparatus and the solid remaining on top of the filter was washed with methanol until the filtrate was neutral and the washed solid was then vacuum dried at 50 ⁰C overnight.

6. The dried powder from step 5 was injection molded at 320 ⁰C with the mold temperature at 100 ⁰C. 7. The Young's Modulus of the 20/80 SWNT-Rs/amorphous nylon injection molded composite produced in step 6 increased 150% (9.2 GPa) over that of neat amorphous nylon, which had a Young's Modulus of 3.7 GPa.

8. The Tg of the composite produced in step 6 increased to 154 ⁰C from 140 ⁰C for neat amorphous nylon.

[0030] Example 3. 0.8/99.2 SWNT-Rs/PPTA Composite Fibers

1. 40 mL of 102wt% sulfuric acid is mixed with 17.6 g of PPTA in a 100 mL resin kettle to make a 19 wt% solution.

2. 14 mL of a 0.5 wt% SWNT-Rs dispersion in oleum (containing 0.14 g of SWNT-Rs by weight) is added to the solution made in step 1 and mixed in the resin kettle for eight h under an inert gas atmosphere.

3. The SWNT-Rs/PPTA acidic mixture made in step 2 is completely dark without stirring (Figure 2a), while it shows stir-opalescence when stirred (Figure 2b). Thus the mixture made in step 2 exhibits liquid crystalline behavior.

Also, the SWNT-Rs/PPTA mixture (dope) when examined under an optical microscope under crossed polarization conditions, as shown in Figures 3a and 3b, clearly shows SWNT-Rs (dark streaks) suspended in an optically anisotropic liquid crystalline PPTA solution.

- The final total concentration of the SWNT-Rs/PPTA mixture in sulfuric acid was 15 wt%.

- Spinning of the SWNT-Rs/PPTA dope was done under the following conditions: air gap: 0.5-1.5 cm; spin-draw ratio: 12.56, dope temp: 55 °C; using a water coagulation bath.

- the Raman ratio of the G-band intensity along and perpendicular to the fiber axis was determined to be 30 to 1, indicating that the SWNT-Rs are highly aligned along the fiber axis.

[0031] The tensile properties for the 0.8/99.2 SWNT-Rs/PPTA composite fibers were determined and are listed in the Table 2. The data shown in Table 2 is for heat treated 0.8/99.2 SWNT/PPTA fiber (400 ⁰C). Table 2.

[0032] Advantageously, the present invention provides a means for generating well- dispersed, loose SWNT-Rs in a variety of polymer matrices. Importantly, the impact of well- dispersed SWNT-Rs is providing composite materials with enhanced mechanical properties, such as tensile strength, tensile modulus, and elongation break. Other properties that may be enhanced include, for example, thermal and electrical properties.

[0033] While the compositions and methods presented herein are exemplary, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are chemically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method comprising: high shear mixing single-wall carbon nanotube ropes in a superacid medium to form loose, acid intercalated SWNT-Rs; placing a polymer in a solvent to form a polymer solution; mixing a portion of the loose, acid intercalated SWNT-Rs with a portion of the polymer solution to form a mixture; and subjecting the mixture to stirring to form a SWNT-Rs/polymer composite solution.

2. The method of claim 1 further comprising shaping the SWNT-Rs/polymer composite solution.

3. The method of claim 2, wherein shaping the composite solution is accomplished by extruding the composite solution.

4. The method of claim 3, wherein shaping the composite solution is accomplished by extruding the composite solution through a spinnerette.

5. The method of claim 3, wherein shaping the composite solution is accomplished by extruding the composite solution through a film die.

6. The method of claim 2 further comprising removing the solvent from the composite solution.

7. The method of claim 6, wherein removing the solvent comprises evaporation.

8. The method of claim 6, wherein removing the solvent comprises direct coagulation.

9. The method of claim 2, wherein shaping the composite solution is accomplished by a process chosen from casting and injecting the composite into a mold.

10. The method of claim 2, wherein shaping comprises placing the composite solution in a mold at elevated temperatures and pressures.

11. The method of claim 1 further comprising removing the solvent.

12. The method of claim 10 further comprising shaping the composite.

13. The method of claim 11, wherein the step of shaping is accomplished by at least one chosen from applying heat and applying pressure.

14. The method of claim 1, wherein the polymer is chosen from nylon, PPTA, PBO, and combinations thereof.

15. The method of claim 1, wherein the polymer is present in an amount ranging from about 50 % by weight to about 99.99% by weight.

16. The method of claim 1, wherein the superacid medium comprises approximately 100% sulfuric acid with an excess of SO₃ ranging from about 1% by weight to about 30% by weight.

17. The method of claim 1, wherein the solvent is chosen from fuming sulfuric acid, methane sulfonic acid, trifluoromethanesulfonic acid, polyphosphoric acid, dimethylformamide (DMF), and N-methylpyrrolidinone (ΝMP).

18. A polymer composite made by any one of claims 1 or 2.