NANOTECHNOLOGY INFORMATION CENTER
Properties, Applications, Research, and Safety Guidelines
What is Nanotechnology?
Nanotechnology is a catch-all phrase for materials and devices that operate at the nanoscale. In the metric system of measurement, "Nano" equals a billionth; therefore a nanometer is one-billionth of a meter. References to nano materials, nanoelectronics, nano devices, nanofabrics, nanogels and nanopowders simply mean the material or activity can be measured in nanometers. To appreciate the size, a human red blood cell is over 2,000 nanometers long, virtually outside the nanoscale range.
Recently, government and private institutions have devoted substantial research into finding potential valuable uses at this scale, as discussed below.
Where does the phrase Nanotechnology come from?
The scientific community generally attributes the first acknowledgement of the importance of the nanoscale range to the brilliant Nobel Laureate physicist Richard Feynman in his famous 1959 lecture "There's Plenty of Room at the Bottom" in which he first proposed that the properties of materials and devices at the nanometer range would present future opportunities. The term reached greater public awareness in 1986 with the publication of "Engines of Creation: The Coming Era of Nanotechnology" by Eric Drexler.
How are nanotechnologies used today?
Despite any former views that nanotechnology is a far-fetched idea with no near-term applications, nanoparticles, nanopowders and nanotubes already play a significant role in industry, environmental remediation, medicine, science and even in the household. A video on interesting new applications using nanoscale materials can also be watched on the PBS NOVA series “Making Stuff: Smaller”. The majority of nanotechnologies commercially used today are based on such nano-sized particles.
Rare earth nanoparticles and rare earth oxide nanopowders are finding application in uses as varied as enhanced fiber optic amplification (EDFA) to the removal of phosphate in the blood of patients with Hyperphosphatemia. Iron Nanoparticles, Iron Oxide Nanopowder, Cobalt Nanoparticles, and several other elemental nanoparticles and alloys form a group of "Magnetic Nanoparticles" with promising application in medical treatment of cancer, magnetic storage and magnetic resonance imaging (MRI).
Carbon nanotubes are single-walled, double walled and multi-walled black nanoscale cylindrical tubes of graphitic carbon with numerous applications. Carbon nanotubes are the stiffest and strongest known fibers and have unique electrical properties. When used as reinforcement fibers, carbon nanotubes can improve the quality and properties of metal, polymer and ceramics. Applications for AE Carbon Nanotubes™ include in flat screen displays, scanning probe microscopes in brushes for commercial electric motors, and in sensing devices. When combined with Aluminum, Copper, Magnesium, Nickel, Titanium, and Tin, single-walled carbon nanotube materials reveal enhanced tensile strength, hardness and characteristics; because of their strength, carbon nanotubes are used in numerous aerospace and automotive capacities, in the fabrication of body armor and tear-resistant cloths, and as an advanced material for stronger and lighter sports equipment. Carbon nanotubes can behave like a conductive metallic or semiconductor depending on their structure, which is useful for nanoscale electronic devices and in electrically conductive films in coatings, plastics, nanowire, nanofiber and in certain bioscience applications. Recently, carbon nanotubes have been demonstrated to create the "darkest" known material absorbing all wavelengths or "colors" of light which will prove useful in solar and electronic applications.
Advances in carbon nanotube technologies are driving the generation of a new class of materials that cross the biomedical, textiles and electronics industries. From clothing to artificial muscles, it appears there is no end to the applications for this new generation of "smart" materials. Carbon nanotubes have the potential to radically change electronics and are among the most likely candidates for miniaturising electronic components beyond the micro-scale.
Titanium/carbon nanotube composites demonstrate a considerable increase in tensile stress, hardness and yield stress. in an additional study, when compared to pure titanium, titanium/carbon nanotube composites displayed increased property hardness of the metal as well as improved elastic modulus.
Graphene is a flat one-atom thick sheet of sp2 carbon atoms densely packed in a honeycomb crystal lattice structure. It is the basic structural element for graphite, carbon nanotubes, and fullerenes. Graphene samples are available as nanoflakes on Si/SiO2 substrate wafers. Each layer is monoatomically thin with a thickness of ~0.34nm, though it is possible to produce multi-layered flakes. Using microscopic imagery, one can easily find the flakes and process them using microelectronic fabrications techniques.
Graphene is the first example of truly two-dimensional crystals, giving it novel electronic and mechanical properties. Because of its high electronic mobility, structural flexibility, and capability of being tuned from p-type to n-type doping by the application of a gate voltage, graphene is considered a potential breakthrough in terms of carbon-based nano-electronics. Research into applications for carbon graphene nanosheets has focused on uses as platforms for next-wave microchips, active materials in field emitter arrays for flat panel screen displays, in biological sensors and medical imaging devices, in solar energy cells, and in high-surface area electrodes for use in bio-science. Graphene is a possible replacement material where carbon nanotubes are presently used.
Surface-functionalized nanoparticles such as Dodecanethiol Functionalized Gold Nanoparticles have controlled surface chemistries which can provide novel methods to change the adhesion (wetting) properties of the particles, re-order their interfacial region or enhance the dispersion properties of the nanopowder in polymers, plastics and coatings for improved magnetic, fluorescent, dielectric, and catalytic properties. Surface Functionalized Nanoparticles have particular application in LEDs, drug delivery systems, sensors and electronics.
Silicon nanoparticles have been shown to dramatically expand the storage capacity of lithium ion batteries without degrading the silicon during the expansion/contraction cycle that occurs as power is charged and discharged. Silicon has long been known to have an excellent affinity for storage of positively charged lithium cations making them ideal candidates for next generation lithium ion batteries. However, the quick degradation of silicon storage units has made them commercially unfeasible for most applications. Silicon nanowires, however, cycle without significant degradation and present the potential for use in batteries with greatly expanded storage times.
Carbon Nanohorns provide a unique combination of strength, electrical conductivity, high surface area and open gas paths, making them an ideal next generation electrode for various fuel cell applications.
Nanotechnology is playing an increasing role in solving the world energy crisis. Platinum nanoparticles produced and marketed under the trade name P-MITE™ are ideal candidates as a novel technology for low platinum automotive catalysts and for single-nanotechnology research. Lanthanum nanoparticles, cerium nanoparticles, strontium carbonate nanoparticles, manganese nanoparticles, manganese oxide nanopowder, nickel oxide nanopowder and several other nanomaterials are finding application in the development of small cost-effective solid oxide fuel cells (SOFCs). Platinum nanoparticles are being used to develop small proton exchange membrane fuel cells (PEM). Lithium nanoparticles, lithium titanate nanoparticles, and tantalum nanoparticles will be found in next generation lithium ion batteries. Ultra high purity silicon nanoparticles are being used in new forms of solar energy cells. Thin film deposition of silicon quantum dots on the polycrystalline silicon substrate of a photovoltaic (solar) cell increases voltage output as much as 60% by fluorescing the incoming light prior to capture.
By narrowly controlling the particles distribution (PSD) of quantum dot nanocrystals to within 10 nanometers, discreet colors with long term photostability can be emitted with wave lengths representing the entire visible spectra. This ability has found application in fluorescent biomarkers and dyes for live cell imaging and antibody conjugates. Additionally, prior to quantum dots, light emitting semiconductors, such as light emitting diodes (LED), could not emit white light. With the development of quantum dots with particle size distributions less than 500 nanometers (nm), LED emissions in the blue range can be achieved which may allow for the commercial use of solid state semiconductors to generate luminescent light.
Nanoscale Z-MITE™ ZnO is being used for its UV absorbing properties to create transparent sunscreen. The particles' small size makes them invisible to the naked eye, so the lotion is clear. At American Elements, we produce nanoscale oxides for a wide variety of applications. For detailed product information on the uses and applications of Z-MITE™, see the Z-MITE™ Product Data Sheet. Z-MITE™ Zinc Oxide nanoparticles, zinc nanoparticles and silver nanoparticles are used for many applications, including as an anti-microbial, anti-bacterial, anti-biotic and anti-fungal agents when incorporated in coatings, fibers, polymers, first aid bandages, plastics, soap and textiles.
Like carbon nanotubes, silicon dioxide nanoparticles, silicon nanoparticles, copper nanoparticles, copper oxide nanoparticles, indium nanoparticles and many others are either electrically superconductive, conductive, or semiconductive particles with far reaching potential in electronics, high speed computing, telecommunication and space travel. Silicon nanotubes and nanocomposites such as boron carbide nanoparticles, silicon carbide nanoparticles and titanium carbide nanopaorticles are also seeing commercial use due their great strength. Plastic nanocomposites are used for strong, lighter, and rust-proof car components. Toyota recently began using nanocomposites in bumpers that makes them 60% lighter and twice as resistant to denting and scratching.
For a given amount of material, as particle size decreases, surface area increases. American Elements nanoscale cerium oxide nanoparticles, platinum nanoparticles, gold nanoparticles, palladium nanoparticles, molybdenum nanoparticles, nickel nanoparticles and iridium nanoparticles have extremely high surface areas which make them idea catalysts for a whole host of chemical synthesis, chemical treatment and chemical cracking applications, including automotive catalytic converters, where surface areas on our materials can reach over 200 m2/g.
The biomedical and bioscience fields have found near limitless uses for nanoparticles. Nanoparticles made of peroxalate ester polymers with a fluorescent dye (pentacene) encapsulated into the polymer have been found to be capable of detecting cancer due to the fact that hydrogen peroxide generated by pre-cancerous human . The dye in the nanoparticles fluoresces when they come in contact with the hydrogen peroxide, which can then be detected as light on medical imaging equipment. When bound to organic molecules, gold and silver nanoparticles are also proving particularly effective in delivering pharmaceutical drugs to the bodies of cancer patients. Artificial bone composites are now being manufactured from calcium phosphate nanocrystals. These composites are made of the same mineral as natural bone, yet have strength in compression equal to stainless steel. Tungsten oxide nanoparticles are being used in dental imaging because they are sufficiently radiopaque (impervious to radiation) for high quality X-ray resolution. The group of magnetic nanoparticles discussed above is being used to both kill cancer cells in malignant tumors and in MRI medical imaging. Coating tungsten particles with DNA and injecting them into plant cells or plant embryos allows for the transformation of plant plastids with lower transformation efficiency than in agro bacterial mediated transformation. The anti-bacterial and anti-microbial effects of many nanoparticles such as silver are well understood technology. Fluorescent nanoparticles are being used by biologists to stain and label cellular components. By changing the size of the quantum dot the color emitted can be controlled. With a single light source, one can see the entire range of visible colors, an advantage over traditional organic dyes.
Nanotechnology is becoming utilized increasingly more in green technology and environmental applications. Certain nanomaterials serve as effective products for environmental clean up. For example, nickel nanocrystals are a reagent for the dehalogenation of trichloroethylene (TCE) , a common groundwater environmental remediation contaminant. A team of researchers from Singapore and the United States developed a lightweight, porous gel embedded with silver nanoparticles that effectively kills bacteria in tainted water, leaving it purified and potable. Introducing disorder into the crystal structure of titanium dioxide nanoparticles changes their color ro black, allowing them to absorb an expanded spectrum of light that engineers could harness to in hydrogen-producing solar cells.
What are the safety, hazard and public policy issues with nanotechnology?
Numerous articles have been published warning of the dangers presented by unregulated nanotechnologies, the most fantastic of which is the threat of "Gray Goo," a hypothesized substance resulting from the runaway dissolution of the earth by self-replicating nanobots. While many of these concerns seem less science than science fiction, the very scale range of these materials do present safety and environmental issues that should be addressed responsibly by industry at least in the same manner as fine particulate materials are currently handled under existing health and safety guidelines.
What is the future of nanotechnology?
Nanotechnology is expected to have an impact on nearly every industry. The U.S. National Science Foundation has predicted that the global market for nanotechnologies will reach $1 trillion or more within 20 years. The research community is actively pursuing hundreds of applications in nanomaterials, nanoelectronics, and bionanotechnology. Most current developments in nanotechnology are in the shape and composition of nanomaterials themselves. Researchers are beginning to understand how to assemble complicated nanostructures and accurately predict their behavior, in addition to experimenting with composites of multiple nanomaterials (like graphene and graphene oxide) and fabricating nanoscale structures of materials never created at that size before. Advanced nanodevices and nanoelectronics that utilize these materials are on the horizon, such as nanorobot drug delivery systems, faster computers, and in sensors.
American Elements is actively involved in pursuing promising research to develop equipment and procedures to manipulate single atoms or molecules with the goal of establishing a new class of man-made atomic structures constructed one molecule at a time. In addition, we support the industrial and academic research efforts by supplying the ultra-pure, advanced materials required to perform nanotechnology research.
American Elements Nanotechnology Products:
Recent Research & Development in Nanotechnology
- Magnetic anisotropy of graphene quantum dots decorated with a ruthenium adatom. Beljakov I, Meded V, Symalla F, Fink K, Shallcross S, Wenzel W. Beilstein J Nanotechnol. 2013 Jul 10;4:441-5.
- Novel molecular and nanosensors for in vivo sensing. Eckert MA, Vu PQ, Zhang K, Kang D, Ali MM, Xu C, Zhao W. Theranostics. 2013 Jul 23;3(8):583-94.
- Prevention and treatment of biofilms by hybrid- and nanotechnologies. Kasimanickam RK, Ranjan A, Asokan G, Kasimanickam VR, Kastelic JP. Int J Nanomedicine. 2013;8:2809-19.
- The effect of active ingredient-containing chitosan/polycaprolactone nonwoven mat on wound healing: In vitro and in vivo studies. Bai MY, Chou TC, Tsai JC, Yu WC. J Biomed Mater Res A. 2013 Aug 14.
- Nanoparticles Mimicking Viral Surface Topography for Enhanced Cellular Delivery. Niu Y, Yu M, Hartono SB, Yang J, Xu H, Zhang H, Zhang J, Zou J, Dexter A, Gu W, Yu C. Adv Mater. 2013 Aug 15.
- Photochemical properties of squarylium cyanine dyes. Ferreira DP, Conceição DS, Ferreira VR, Graça VC, Santos PF, Ferreira LF. Photochem Photobiol Sci. 2013 Aug 15.
- Baculoviral transduction facilitates TALEN-mediated targeted transgene integration and Cre/LoxP cassette exchange in human-induced pluripotent stem cells. Zhu H, Lau CH, Goh SL, Liang Q, Chen C, Du S, Phang RZ, Tay FC, Tan WK, Li Z, Tay JC, Fan W, Wang S. Nucleic Acids Res. 2013 Aug 13.
- Transparent, conductive gold nanowire networks assembled from soluble Au thiocyanate. Morag A, Ezersky V, Froumin N, Mogiliansky D, Jelinek R. Chem Commun (Camb). 2013 Aug 14.
- Electrochemical synthesis on single cells as templates. Tam J, Salgado S, Miltenburg M, Maheshwari V. Chem Commun (Camb). 2013 Aug 15.
- Coordination Polymers and Metal-Organic Frameworks Derived from 4,4'-Dicarboxy-2,2'-bipyridine and 4,4',6,6'-Tetracarboxy-2,2'-bipyridine Ligands: A Personal Perspective. Kruger PE. Chimia (Aarau). 2013;67(6):403-10.
- How Nanoscience Translates into Technology: The Case of Self-Assembled Monolayers, Electron-Beam Writing, and Carbon Nanomembranes. Palmer RE, Robinson AP, Guo Q. ACS Nano. 2013 Aug 14.
- Lattice Boltzmann modeling of directional wetting: Comparing simulations to experiments. Jansen HP, Sotthewes K, van Swigchem J, Zandvliet HJ, Kooij ES. Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Jul;88(1-1):013008.
- Synthesis of Exclusive Au11 (PPh3 )8 Br3 against the Cl Analogue and the Electronic Interaction between Cluster Metal Core and Surface Ligands. Wu Z, Jin R. Chemistry. 2013 Aug 13.
- Mesenchymal Stem Cells and Nano-structured Surfaces. Zhou Y, Chakravorty N, Xiao Y, Gu W. Methods Mol Biol. 2013;1058:133-48.
- Composite electrospun nanofibers for influencing stem cell fate. Polini A, Scaglione S, Quarto R, Pisignano D. Methods Mol Biol. 2013;1058:25-40.