Nanomaterials: Unique Properties and Diverse Applications
Nanomaterials Products and Applications
The smallest nanomaterials have unique properties not found in bulk materials or in molecular structures. The precise shape and composition of a nanomaterial determines its physical and chemical properties.
These properties are being used in products such as polymer nanocomposites structural parts, solar cells that generate more energy and carbon nanotube sheets that improve the performance and durability of airplanes, cars and power tools.
Chemical nanomaterials are used to enhance a wide range of consumer products and industrial applications. They are also used in catalysis, environmental sensing, and other technological functions.
Nanomaterials can be produced by cutting down macro structures to the nanoscale (top-down approach) or assembled from atoms and molecules. The latter process is called bottom-up manufacturing.
Nanomaterials are found in a number of household and industrial products, including cleaning supplies like degreasers and stain removers; anti-corrosion coatings for tools and machines; lubricants that reduce wear; and self-cleaning paints that seal dirt inside a sealed film. They are also used in modern, human-safe insulation, and carbon nanotubes that bend when electrically charged, allowing lighter bats and aircraft wings. In addition to this, they can be used in catalysis to boost chemical reactions and avoid pollution.
In electronics, nanoscale materials can be used to improve the performance of devices such as displays for smart phones and e-book readers. Examples include semiconductor nanomembranes, conductive inks, and flexible display screens.
Carbon nanotubes are another emerging nanotechnology with a wide range of potential applications. These microscopic tubes have exceptional physical properties, including thermal conductivity that rivals diamond, mechanical strength that outperforms steel, and high electric conductivity.
Nanoparticles are being developed for medical applications, such as incorporating gold into nanoparticles that bind to cancerous cell growths or using silver nanoparticles in bandages to smother harmful bacteria. Other applications include enhancing agricultural cultivation by helping to reduce pesticide use, and improving transportation infrastructure through sensors and vehicles that can communicate with one another. This technology also makes it possible to harvest and store renewable energy.
The health care industry is developing a wide range of nanomaterials for use as medical devices and pharmaceuticals. These nanomaterials are being used to deliver drugs directly to cancerous cells, or to the lining of arteries to prevent blood clots from forming.
Nanomaterials can appear naturally or be engineered to perform a specific function. They vary in chemical composition, primary particle size and shape, surface coatings, and strength of particle bonds. Examples include quantum dots, silver dendrimers and carbon fullerenes (Buckyballs), and carbon nanotubes.
Some nanomaterials are ingested or inhaled, and may end up in aquatic ecosystems, where they could cause harm. The NTP’s three core agencies — NIEHS, the National Center for Toxicological Research at the Food and Drug Administration and the Centers for Disease Control and Prevention — are working together to develop scientific methods to evaluate these materials for their potential hazards.
Nanotechnology is used to make products that are lighter, stronger, more durable or have better electrical or thermal conductivity. For example, carbon nanotubes help make bicycle frames and tennis rackets lighter and more stiff. They are also used in epoxy coatings that make kayaks and boats faster and more stable in water, and to keep golf balls bouncy.
EPA scientists are working on ways to use nanotechnology to monitor chemicals and harmful substances in the environment, and to identify potential hazards. They are developing nanoparticle-specific models to understand how the unique properties of these particles may impact their release, transformation and exposure in the environment.
Other projects include a nanotech sensor that can detect chemical and biological agents in the air or soil. And they are studying self-assembled monolayers on mesoporous supports and dendrimers, and carbon nanotubes to see if these materials can be used for toxic site remediation.
Energy scientists are finding new ways to use nanomaterials to improve the efficiency of existing energy-generating methods and find new ways to create power. They’re working to develop insulating and conductive nanomaterials that are lighter, stronger, and have less chemical reactivity than their bulk counterparts.
The results of these efforts can be seen in products such as a solar steam generator that uses sunlight to produce electricity, and lubricants made with carbon nanotubes that reduce friction without increasing energy consumption. Researchers are also working to create solar panels that are lighter and more efficient and to find ways to harness the solar radiation that bypasses Earth each day.
Other examples include clear nanoscale films that make eyeglasses, computer and camera displays, and windows water- and residue-repellent, antireflective, self-cleaning, resistant to ultraviolet or infrared light, or electrically conductive; semiconductor quantum dots that enable TVs and displays to display more colors with greater efficiency; and batteries that charge faster, hold more power, and last longer.