Battelle Scientists Reveal Apparatus for Manufacturing a Variety of Nanoparticles in High Concentration Including C70, C76, and C84

In U.S. Patent Application 20090317336, Battelle Memorial Institute (Columbus, Ohio) inventors Amit Gupta (Richland WA),  William C. Forsythe and Mark L Clark disclose a method and apparatus for generating high purity nanoparticles, including fullerenes, carbon nanotubes, titanium dioxide and cerium oxide (CeO) at high concentration

The apparatus uses a solid aerosol disperser in communication with a furnace tube having a vaporization chamber and a dilution chamber. A heating element surrounds the furnace tube. Heat from the heating element heats bulk materials contained within a gas flow in the vaporization chamber to a temperature sufficient to convert the bulk materials to a vapor phase.

Vaporized bulk materials are then moved to a dilution chamber, where an inert gas is introduced through a dilution gas port. The flow of the inert gas into the dilution chamber through the dilution gas port is sufficient to eject the bulk material from the exit of the dilution chamber, thereby condensing the bulk material into nano sized particles in a gas flow of sufficient volume to prevent agglomeration of the nano sized particles.

The nanomaterials generated by the apparatus are suitable for use in applications requiring high concentration and high purity, including inhalation toxicology studies, manufacturing applications, occupational safety and health studies, and as drug delivery systems.

The manufacturing method  is particularly well suited and enables the generation of high concentrations of nano-sized particles of C₆₀ aerosols. It is also well suited to the production of cerium oxide, carbon nanotubes, titanium dioxide, C₇₀, C₇₆, and C₈₄.  The apparatus features the use of a solid aerosol disperser.

While these commercially available solid aerosol dispersers can be configured to provide a flow of solid particles in a gaseous flow, the particle size of their output is not sufficiently small to meet the objectives of the Battelle apparatus.

 For example, and not meant to be limiting, beginning by milling commercially available bulk material consisting of C₆₀ particles supplied by SES Research, Houston, Tex., the solid aerosol disperser available from Battelle Memorial Institute (Columbus, Ohio), can then provide a constant flow of C₆₀ having particles sized between about 1 .mu.m and about 1.5 .mu.m mass median aerodynamic diameter (MMAD) in a flow of nitrogen of about 6-6.5 LPM.

Battelle’s  invention provides a method whereby those particles are reduced further in size while maintaining purity, such that the resulting particles are of less than 100 nm count median diameter (CMD) and do not exhibit chemical decomposition of C₆₀ to an amorphous phase or to carbon black. Accordingly, the "nano sized particles" produced by the Battelle invention are defined herein as particles having less than 100 nm count median diameter (CMD).

Cancer Fighting Water Soluble Carbon Nanotubes and Quantum Carbon Dots Testing to Begin

Cromoz Inc (Research Triangle Park, NC) will initiate testing of  a water-soluble carbon nanotube-based cancer drug delivery system in Hyderabad, India. The water-soluble carbon nanotubes, which have functional groups on the walls that allows for conjugation with cancer drugs, were developed in partnership with the Indian Institute of Kanpur (ITT). The conjugated carbon nanotubes serves as a drug delivery vehicle with the ability to target the cancer site which has the potential to increase the drug efficacy.

The target drug delivery reduces the amount of chemotherapeutic drugs used in cancer treatment and minimizes the side effects. The reduced dosage without compromising the drug efficacy will make the cancer treatment more potent and targeted to killing the cancer and more affordable and available to a larger community.

"Certain percentage of these carbon nanotubes are composed of smaller Quantum Carbon Dots," stated Iffat Allam, President & CEO of Cromoz Inc. "The nontoxic carbon quantum dots can be used as Fluorescent Probes for imaging living biological processes and to monitor cancer growth. These quantum dots are of assorted sizes, they absorb and emit light at different wavelengths. This results in multi-colored images which will be very useful to diagnose a specific organ and its function and the effect of drug delivery to specific cancer sites."

Cromoz has successfully conjugated cancer drugs such as Taxol and Gemcitabine and is currently working with Johns Hopkins Cancer Center in Maryland, USA. Early next year Cromoz will initiate a research and development (R&D) and manufacturing facility in Biotech Park in Hyderabad, India.

Cromoz Inc., is an advanced materials innovator and manufacturer focused on the development of carbon nanotechnology-enabled products primarily for the biomedical industry. These innovative products are based on two proprietary technologies, water-soluble carbon nanotubes and water-soluble fluorescent carbon quantum dots. The CNTs (Carbon Nano Tubes) are insoluble in water. Some have used a common technique to wrap the CNT with hydrophilic molecules to make them disperse in water. Cromoz scientists have successfully derivatized the multi-wall of CNTs and Carbon Dots to make them water-soluble. These derivatized CNTs are bio-friendly, fluorescent and hence well suited for drug delivery.

Marine Carbon Nanotube Epoxy Coatings Cut Ship Fuel Consumption by 10%

The Norwegian company Advanced Marine Coatings based in Gamle Fredrikstad specializes in the development of environmentally compatible, heavy-duty anti-corrosion coatings for sea-going vessels is the first company to apply  The “Green Ocean Coating Heavy Duty” coatings which are formulated with Baytubes® carbon nanotubes (CNT) from Bayer MaterialScience. The coating give the ships with them very high abrasion resistance. The coatings also reduce the flow resistance between the ship's hull and the water, thereby enabling a significant reduction in fuel consumption and carbon dioxide (CO2) emissions.

“According to our knowledge, this is the first application of Baytubes® carbon nanotubes in marine coatings”, says Dr. Raul Pires, head of Global Activities for Nanotubes and Nanotechnology Products at Bayer MaterialScience. The coatings are suitable for both new vessels and for subsequent repair and maintenance coatings and reduce fuel consumption by as much as 10%.

The Berge Arzew with “Green Ocean Coating Heavy Duty” Coatings

Photo Credit: Bayer MaterialSceince: The “Green Ocean Coating Heavy Duty” coatings from Advanced Marine Coatings are formulated with Baytubes® carbon nanotubes from Bayer MaterialScience, which gives them very high abrasion resistance. The coatings also reduce the flow resistance between the ship's hull and the water, thereby enabling a significant reduction in fuel consumption that if adopted worldwide could reduce CO2 emissions by 70 million tons.

The Green Ocean Coating Heavy Duty systems are two-component epoxy mastic resins coatings with extremely high resistance to water, making them particularly suitable for marine coatings and in particular for the part of the hull below the surface of the water. Thanks to the addition of Baytubes® carbon nanotubes, these have a very smooth surface and thus help to save fuel and reduce carbon dioxide emissions.

Another major advantage is the reduction of maintenance costs. The ban on organic tin compounds for use as antifouling agents to prevent organic growth has necessitated relative frequent cleaning of the coating surface on the ship’s hull to ensure cost-effective transport. “We hope that the smoothness and greater hardness of the coating will provide better durability and will allow us to extend the cleaning cycle. Thanks to the use of Baytubes®, the systems represent both the most ecological and the most economic solution,” says Stein Dietrichson, Managing Director of Advanced Marine Coatings.

The first ship to be coated with this system was the Berge Arzew, an LNG (liquified natural gas) tanker with a capacity of 138,000 cubic meters. Extensive test coatings of a Green Ocean Coating were successfully applied to a surface area of 700 square meters. The VOC-free system (VOC stands for volatile organic compounds) was applied in film thicknesses of up to 400 micrometers. “The results so far are highly promising. The nanotubes evidently make for a very smooth, pore-free surface,” says Dietrichson.

A film shot in spring 2007 at NTNU and SINTEF Marintek in Trondheim, shows the AMC R & D manager, Eng. Paal Skybak,  who explains about nano modified paints and the Green Ocean development program.
The film is focused on the environment with much attention on CO₂ emissions and how sleek coatings enable energy savings of up to 10%. The consequences of this on a global basis could be a total reduction in CO₂ emissions of more than 70 million tons. This was explained by a Bellona representative, who also said that this will be an important contribution to the effort to improve the global climate by reducing CO2 emissions.
The program may be seen by following this link to: Paint can make ships more environmentally friendly

Mezmerize Micro Fibers Increase MEMS Durability Over Billions of Cycles

Fibrous micro-composite materials can be formed from micro fibers and be used to build micro-electro mechanical systems (MEMS) that do not show fatigue after the billions of cycles. The fibrous micro-composite materials are utilized as the basis for a new class of MEMS by Mesmerize. Magnetic, piezoelectric, electrostatic, electrothermal, and electrostrictive responsive fibers are used to form a variety of micro-electro-mechanical devices.   In addition to simple fiber composites and microlaminates, fibrous hollow and/or solid braids, can be used in structures where motion and restoring forces result from deflections involving torsion, plate bending and tensioned string or membrane motion. These materials will enable simultaneous high operating frequencies, large amplitude displacements and or rotations, high reliability under cyclical stresses, according to inventor Shahyaan Desai.

Desai is  a founder of Mesmerize (Ithaca, NY)  which is commercializing  MEMS devices from fabricated nanofibers without the use of a matrix material. Fibrous elements are formed using high strength, micron and smaller scale fibers, such as carbon/graphite fibers, carbon nanotubes, fibrous single or multi-ply graphene sheets, or other materials having similar structural configurations. Devices can be built where fibers are attached only at a substrate edge (e.g. cantilevers, bridges). Motions can be controlled by adjusting the linkage between multiple fibers with weak coupling (e.g. base, tip, in-between). Driving mechanisms include base-forcing (magnetics, piezo, electrostatics) or tip forcing (magnetics). Mirrors may be formed on free ends of cantilevers to form optical scanners.

Mezmerize is a designer and manufacturer of micro-electromechanical System (MEMS) mirrors and mirror modules based on a novel carbon fiber materials platform. The unique material properties of carbon fibers permit, for the first time, the development of micro-mirrors that can simultaneously deflect through large angles and reach high scanning speeds. Mezmeriz is currently working with partners to integrate their carbon fiber micro-mirror modules in pico-projectors and laser scanning units for laser printers enabling novel functionality in these devices.

Although MEMS manufacturers have pushed to develop silicon (both polycrystalline and single crystal) and other material-based structures, the resulting systems still lack the needed mechanical properties, according to U.S. Patent 7,616,367 held by Cornell Research Foundation, Inc. (Ithaca, NY). A specific example is the case of MEMS based optical scanners and switches (OMEMS). Such devices need to produce large angular deflections (several tens of degrees) and resonant frequencies exceeding tens of kilohertz with lifetime reliability over billions of cycles.

Monolithic materials, such as silicon, metal and ceramic thin films currently used to produce MEMS lack the required combination of high elastic stiffness, high strength, high fatigue lifetime and low density (mass per unit volume) i.e., the basic mechanical flexibility and flaw tolerance necessary for many potential MEMS applications. Polymers are not adequate since they are too flexible and have low strength which limits them to low frequency operation in devices where low forces and/or displacements are required, such as valves and fluidic pumps.

Consequently, moving component MEMS, such as optical scanners, are nearly non-existent commercially today. Most successful applications of MEMS remain based on quasi-static devices such as pressure and acceleration sensors. One moving component MEMS is a digital light processor that is based on bistable positioning of aluminum MEMS mirrors.

The need for advanced capability MEMS devices can be illustrated through a particular application--the MEMS based optical scanner (an OMEMS). Such scanners are envisioned for large area display applications using three-color scanning. Early MEMS optical scanners utilized a torsional silicon micro-mirror produced using wet etching. It was capable of deflecting a beam through a 0.8.degree. angle at a resonance frequency of 16.3 kHz. The majority of OMEMS scanners in development today are still designed using similar thin beams of silicon acting either as torsion bars (around which a silicon mirror element rotates) or as cantilevers (which vibrate to provide the scanning motion). Both of these structure types are efficient, with no moving parts to wear.

General applications are dependent on the resonance frequency, the maximum deflection, and the maximum restoring force--with higher values of each normally desired. These properties are dependent on the size, shape, and mechanical properties of the underlying materials. However, materials used in traditional IC-based MEMS fabrication lack the mechanical characteristics required to allow specific tailoring and optimization for many applications. There is no current way to design simultaneously for high frequency operation, large amplitude deflection, low operating power, robustness, and long-term reliability under cyclic stresses with existing material systems. The basic problem with silicon, and monolithic materials in general, is that while sufficient elastic stiffness, their strength and fatigue lifetime is too low and density too high. This combination limits the ultimate deflection amplitude and frequency, and increases power requirements to sustain oscillation. having sufficient elastic stiffness, their strength and fatigue lifetime is too low and density too high. This combination limits the ultimate deflection amplitude and frequency, and increases power requirements to sustain oscillation.

Fundamental limitations exist in the performance of materials currently used for MEMS and micro-mechanical devices. These materials such as Si, SiO2, SiC, metals, Si3N4 cannot provide large deflections (>100 um) at high speeds (>kHz) necessary for many MEMS actuator applications hampering their widespread commercialization. Most of all, the existing materials do not have the fatigue life necessary to undergo repeated large deformations over the billions of cycles that most actuator MEMS applications require.  Materials developed by Desai overcome may of the problems associated with silicon MEMS devices.

Organosilicon Electrolyte and Carbon Nanotubes Make More Power Supercapacitors

Wisconsin Alumni Research Foundation (Madison, WI) reveals a more powerful electrochemical double-layer capacitor using organosilicon electrolytes and carbon nanotubes in U.S. Patent 7,612,985. University of Wisconsin inventors Viacheslav V. Dementiev, Robert C. West, Robert J. Hamers and Kiu-Yuen Tse say the electrolytes can provide improved supercapacitors, and improved electrodes and separators for use in capacitors and batteries. They could be used in electric and hybrid-electric vehicles, satellites, wind generators, photovoltaics, copy machines, high power electronic household appliances, electric tools, electric power generation, and electric distribution systems.

Lingzhi Zhang, Robert West and Viacheslav Dementiev have also developed lithium batteries using pure polysiloxane electrolytes. When compared to the carbonate electrolyte, the polysiloxane electrolyte proved to be superior in every way. In a test to simulate the batteries' life spans, the two batteries are charged and discharged repeatedly. The battery using the carbonate electrolyte failed after 500 cycles, which is equivalent to approximately two years of use. Results from this same test show a projected lifetime of over twelve years for the battery using the polysiloxane electrolyte. This increase is a direct result of polysiloxane's superior electrochemical stability. Furthermore, silicone electrolytes are nonflammable, environmentally benign and nontoxic, all of which are necessary for the battery to be implantable in the human body.

Quallion already uses the electrolytes developed at UW-Madison in new lithium batteries that power an implant device called the Bion. This device is a neurostimulator capable of alleviating many of the debilitating symptoms of epilepsy, strokes, Parkinson's disease and spinal cord injuries. The Bion is only 18 millimeters long and three millimeters in diameter. It is implanted using a hypodermic needle near the point where a nerve connection has been broken. The neurostimulator relays electrical signals from one side of the severed nerve to the other, effectively bridging the gap.

Crack Proof Cement Made with Carbon Nanotubes, Technology Licenses Available

Northwestern researchers invented a process to use multi-walled carbon nanotubes (MWCNTs) at very low levels in conjunction with additives and mixing methods that provide excellent MWCNT dispersion in cement matrixes and afford significant improvement in cured mechanical properties. An aqueous MWCNT (0.08 wt% cement basis) additive solution, after suitable mixing, is blended into cement under ASTM procedures, cast and cured. Scanning electron microscopy (SEM) analysis of fracture surface specimens after 18 hours reveals isolated MWCNT fibers with a high degree of dispersion in the matrix. The uniform MWCNT distribution contributes to the observed increase in cured cement mechanical properties. Over 45% increase in the 28 day flexural strength is realized at the 0.08 wt% MWCNT loading versus the unmodified control. This modest MWCNT addition inhibits cracking at the nanoscale level and provides a cement matrix essentially “crack free”. The current invention promises a cost effective technology to provide high strength cements in a direct and scalable process.

Most construction cements today are hydraulic, and generally based on Portland cement, composed primarily of limestone, certain clay minerals and gypsum. Effort to mitigate structural failures in cement is a constant endeavor that has employed a range of materials. Although microfiber reinforcement has led to significant improvement of cement mechanical properties, flaws at the nanoscale remain. Carbon nanotubes (CNTs) have been added to cementitious matrices at 0.5 to 1.0 wt% loadings to overcome such defects but suffered from poor dispersion and cost.

Northwestern researchers Surendra P. Shah, Maria S. Konsta-Gdoutos, and Zoi S. Metaxa were able to overcome the major obstacle to the manipulation and use of carbon nanotubes for reinforcement in cementitious materials which has been their poor dispersion in cement. A composite cement material was prepared from cement material and carbon nanotubes from about 0.02 wt % to about 0.10 wt % based on weight of cement material. The process for preparing such cement compositions includes sonicating a mixture of a surfactant, water, and carbon nanotubes; blending the dispersion and the cement material to form a cementitious paste. The composite cement materials are useful in a variety of cement applications where a reduction in nanoscale flaws and fractures is desired.

The nanocomposite cementitious material exhibits a reduction of autogenous shrinkage of at least 30% after 96 hours from casting as compared to the same cementitious material without carbon nanotubes. The nanocomposite cementitious material exhibits a modified nanostructure so that the average values of stiffness and hardness of C-S-H, as determined by nanoindentation tests, are higher compared to the same cementitious material without carbon nanotubes. The nanocomposite cementitious material exhibits an increase of the Young's modulus of at least 15% up to about 55% as compared to the same cementitious material without carbon nanotubes. The nanocomposite cementitious material exhibits an increase in flexural strength of at least of 8% up to about 40%. as compared to the same cementitious material without carbon nanotubes.

CNT cement composites are expected to find wide application for highway structures, bridges, pavements, runways for airports, continuous slab-type sleepers for high speed trains and in general in all applications of conventional and high strength concrete, as well as in manufactured precast elements for residential and commercial buildings.

Further details of the invention are revealed in United States Patent Application 20090229494. The technology is available for licensing from Northwestern University. Interested parties should contact Technology Transfer @ Northwestern 1800 Sherman Avenue - Suite 504 Evanston, IL 60201 Phone: 847-491-3005 Fax: 847-491-3625 E-mail: jcowan(at) northwestern.edu

Boeing Develops Nano Rhenium Composite Alloys for Space Applications

The Boeing Company (Chicago, IL) developed a process that reduces the amount of the rhenium used in high temperature applications such as rocket propulsion systems without sacrificing its high temperature and mechanical properties. Cryomilling in the presence of nitrogen is used to prepare rhenium alloys with a stable fine grain structure at high temperatures, according to inventors Jerry W. Brockmeyer and Clifford C. Bampton. The rhenium nano alloy has high temperature strength and ductility superior to conventionally processed rhenium and earned Boeing U.S. Patent 7,592,073. The rhenium alloy contains a refractory compound which may include one or more of hafnium (Hf), zirconium (Zr), tantalum (Ta), silicon (Si), vanadium (V), and titanium (Ti), and which makes up between 0.1% and 10% of the alloy by weight.

The refractory compound comprises a nano-scale dispersion that is incorporated into the conventional rhenium structure. The nano-scale dispersion acts as grain boundary pins that result in a relatively fine grained, equiaxed structure that helps to improve the mechanical properties of the alloy and helps to minimize the growth of large grains during operations at high temperatures. Carbon nanotubes, similar to the refractory compounds discussed above, may also act as nano-scale pins that help prevent the growth or the rhenium grains at higher temperatures. Carbon nanotubes typically have a lower density and weight than refractory compounds containing refractory metals. As a result, the overall weight/density of the rhenium alloy may be reduced which may result in reduced weight structures and/or enhanced density-specific properties.

Many rocket propulsion systems use either a pressure fed system or a turbopump system that transfers propellants to the combustion chamber where they are mixed and burned to produce a high velocity stream of heated gases. The stream of heated gases is then exhausted through one or more nozzles to provide the desired thrust. Typically, combustion takes place at temperatures that may be in excess of 6000 F., which may be higher than the melting point of most conventional engine materials. As a result, in the absence of active cooling, it may be necessary to line the interior of the combustion chamber with a material having a high melting point and oxidation resistance. Boeing’s nano rhenium alloys have melting temperatures as high as 6150 degree F (3400 degree C).

Iridium-coated rhenium is a material that is commonly used to line the interior of the combustion chamber. Iridium provides high temperature oxidation resistance and has an intrinsic resistance to oxidation. Rhenium has a higher melting point than iridium and excellent high temperature structural capability. Iridium and rhenium are dense materials that are prohibitively expensive. As a result, the use of iridium and rhenium may increase the overall cost and weight of the propulsion system. Boeing is able to reduce the amount of rhenium needed while improving the alloys’ heat resistance.

The processing of rhenium presents several challenges. In many applications, chemical vapor deposition (CVD) fabrication is used. Typically, high temperatures are needed to deposit rhenium using CVD. However, conventional equipment for CVD produces temperatures on the order of 1000.degree. C., which is much lower than the melting point of rhenium. CVD also typically requires relatively expensive starting materials and processing reactors that are relatively expensive to run and maintain. Other methods of processing rhenium, such as electrodeposition, may also present challenges and may result in the rhenium having an undesirable grain size. Post-processing, e.g. machining of rhenium, may also be difficult because of the high work hardening coefficient of rhenium.

The advantageous properties of rhenium may also be adversely affected, in part, by the processing conditions. For instance, in many cases rhenium properties may be dynamic when exposed to high temperatures. This dynamic behavior may result from grain growth that can occur at higher operating temperatures. Grain growth may decrease the mechanical properties of rhenium. Additionally, current methods of processing rhenium typically result in relatively large grain structures or grain structures that have an acicular grain structure. Such grain structures tend to increase the difficulty of processing rhenium and may also result in the rhenium having reduced mechanical properties, such as strength, at higher operating temperatures.

Many rhenium processing disadvantages are overcome by "cryomilling" which is the fine milling of metallic constituents at extremely low temperatures. Cryomilling takes place within a high energy mill such as an attritor with metallic or ceramic balls. During milling, the mill temperature is lowered by using liquid nitrogen or a similar compound to a temperature of between -240.degree. C. and -150.degree. C. In an attritor, energy is supplied in the form of motion to the balls within the attritor, which impinge portions of the metal alloy powder within the attritor, causing repeated comminuting and welding of the metal. As-milled grain sizes in these metal powders are on the order of 50 to 100 nm.

Copper Enigma and Temperature Selection Critical to Nanocarbon Shape Formation

Catalytic Materials LLC (Pittsboro, NC) researchers Terry K. Baker and Nelly M. Rodriguez discovered how to make multi-faceted multiwall carbon nanotubes with crystallinities ranging from greater than 95% to substantially 100% as well as other nanocarbon forms by controlling temperature in the presence of specific catalysts. Carbon nanostructures are generally prepared by reacting the powdered catalyst in a heating zone with the vapor of a suitable carbon-containing compound. While the art teaches a wide variety of carbon-containing compounds as being suitable for the preparation of carbon nanostructures, the inventors found that only a mixture of CO and H2 will yield carbon nanofibers with unexpectedly high crystallinities and in the unique structures of nanofibers of their invention in the temperature range of about 550 degree C to about 725 degree C.

Catalysts used to prepare the carbon nanofibers are bulk metals in powder form wherein the metal is selected from the group consisting of iron, iron-copper bimetallics, iron-nickel bimetallics and also cobalt-magnesium oxide mixtures. It is well established that the ferromagnetic metals, iron, cobalt, and nickel, are active catalysts for the growth of carbon nanofibers during decomposition of certain hydrocarbons or carbon monoxide. Efforts are now being directed at modifying the catalytic behavior of these metals, with respect to nanofiber growth, by introducing other metals and non-metals into the system. In this respect, copper is an enigma, appearing to be relatively inert towards carbon deposition during the CO/H2 reaction. Thus, it is unexpected that Fe or the combination of Cu or Ni with Fe would have such a dramatic effect on carbon nanofiber growth in the CO/H2 system in the temperature range of about 550 degree C to about 725.degree C. For the cobalt-magnesium oxide system the preferred temperature range is 580 degree C. to about 600 degree C. Iron-nickel catalysts and cobalt-magnesium oxide are preferred for preparing the carbon nanostructures.

The following figures illustrates the various shapes formed by Catalytic Materials, LLC’s patented process as well as the temperatures at which certain shapes are formed as revealed in U.S. Patent 7,592,389.

















(click on images to enlarge and for greater clarity)

FIG. 1a is a representation of a platelet carbon nanofiber, which is comprised of substantially graphite sheets that are substantially perpendicular to the longitudinal axis, or growth axis, of the nanofiber.

FIG. 1b is a representation of a cylindrical carbon nanostructure that is comprised of continuous carbon sheets and is in the form of tube within a tube within a tube with a substantially hollow center.

FIG. 1c is a representation of a ribbon carbon nanofiber comprised of non-connected graphitic sheets that are aligned face-to-face and substantially parallel to the longitudinal axis of the nanofiber.

FIG. 1d is a representation of a faceted tubular carbon nanofiber and is comprised of continuous sheets of graphic carbon but having multifaceted flat faces. The graphitic sheets are also substantially parallel to the longitudinal axis of the nanofiber.

FIG. 1e is a representation of a herringbone carbon nanofiber wherein the graphitic platelets or sheets are at an angle to the longitudinal axis of the nanofiber.

FIG. 1f is a representation of multiwall faceted tubular carbon nanofibers

The carbon nanofibers can be dispersed in a polymer by various well-known techniques such as melting and kneading to form an admixture that can be subsequently shaped to form an electrically conductive article. Multi-faceted carbon nanotubes are more conductive electrically than cylindrical carbon nanotubes. The use of conductive nanofibers is highly desirable since a given weight of such a material generates a large number of contact points within a polymer matrix. The widespread interest in electrically conductive polymers is stimulated by the possibility that such materials can have utility in such things as semiconductor chips, integrated circuits, lightweight battery components, sensors, electro-chromic displays, anti-static coatings, static dissipation, electromagnetic and radio-frequency interference shielding, fuel hoses, connectors and packaging items. It is well established that the incorporation of certain types of carbon nanofibers into polymeric materials can impart electrical conductivity to such materials that are generally regarded as insulators.

CoMoCat® Process Revealed in Patent

SouthWest NanoTechnologies (SWeNT) CoMoCat® manufacturing process produces SWNT of high quality at very high selectivity, and with a remarkably narrow distribution of tube diameters. In this method, SWNT are grown by catalytic CO disproportionation (decomposition into C and carbon dioxide) at 700-950°C in flow of pure CO at a total pressure that typically ranges from 1 to 10 atm. The technology was invented by University of Oklahoma Professor Daniel Resasco, patented by the University and licensed to SWeNT.

Figure CoMoCat® Process as Presented in U.S. Patent 7,585,482.



The figure shows a series of process steps A-Q which represent a method of continuous catalytic production of carbon nanotubes. Southwest Nano Technologies Inc. (SWeNT) located in Norman, Oklahoma is commercializing this method. The process was developed at the University of Oklahoma by Prof. Daniel Resasco, who is SWeNT’s chief scientist, a company founder and directs the carbon nanotube research team that invented the CoMoCAT® catalytic process. The process is able to grow a significant amount of SWNT in a couple of hours, maintaining a high selectivity.


The process is protected by U.S. Patent 7,585,482.