materials and coatings
Carbonated Cement for Production of Concrete with Improved Properties
The NASA cement innovation describes a method to make solid carbon material from CO<sub>2</sub> captured during the cement-making process, and for using that carbon material in the mixture to improve cement properties. Doing so provides a direct use for the captured CO<sub>2</sub>, eliminating any CO<sub>2</sub> storage/disposal issues and providing an improved cement product. The innovation employs a chemical reaction, known as the Bosch process, which uses hydrogen gas and catalysis to reduce the CO<sub>2</sub> to solid carbon and water. Cement manufacturing is uniquely suited to the use of the Bosch process. Cement manufacturing requires high temperatures, and harnessing this excess heat limits the total energy required to maintain a Bosch process at a cement plant. Also, cement contains iron, a metal shown to be an exceptional catalyst for the Bosch process. Thus, the cement product itself can be used as the catalyst for the reaction, also serving as a carbon sink. This eliminates any requirements for the storage or disposal of the waste carbon captured from CO<sub>2</sub> emissions. Test evaluations at the bench scale have provided encouraging indications of enhanced mechanical properties for the carbon-containing cement materials. In particular, the findings suggest that the carbon in the concrete might delay the environmental breakdown of concrete due to the blocking effect of the carbon on harmful ions (e.g., chlorine).
Lightning Mitigation and Damage Detection
The NASA technology can be used to protect tall structures from lightning strike damage. When a lightning leader propagates through the atmosphere in the vicinity of a tall structure, the lightning electromagnetic emissions generated from the moving electrical charge will impinge upon the tall structure before the actual charge attaches. As the lightning leader propagates closer to the tall structure, the radiated emissions at the tall structure will grow stronger. The SansEC sensor is designed to operate within the lightning radiated emission spectrum and thus is passively powered by the external oscillating magnetic field from the lightning itself. The sensor will resonate and generate its own oscillating magnetic and electric fields which have been demonstrated to influence lighting attachment and propagation.
Activated Metal Treatment System (AMTS) for Paints
PCBs have been shown to cause cancer in animals and to have other adverse effects on immune, reproductive, nervous, and endocrine systems. Although the production of PCBs in the United States has been banned since the late 1970s, many surfaces are still coated with PCB-laden paints. The presence of PCBs in paints adds complexity and expense for disposal. Some treatment methods (e.g., use of solvents, physical removal via scraping) are capable of removing PCBs from surfaces, but these technologies create a new waste stream that must be treated. Other methods, like incineration, can destroy the PCBs but destroy the painted structure as well, preventing reuse. To address limitations with traditional abatement methods for PCBs in paints, researchers at NASAs Kennedy Space Center (KSC) and the University of Central Florida have developed the Activated Metal Treatment System (AMTS) for Paints. This innovative technology consists of a solvent solution (e.g., ethanol, d-limonene) that contains an activated zero-valent metal. AMTS is first applied to the painted surface either using spray-on techniques or wipe-on techniques. The solution then extracts the PCBs from the paint. The extracted PCBs react with the microscale activated metal and are degraded into benign by-products. This technology can be applied without removing the paint or dismantling the painted structure. In addition, the surface can be reused following treatment.
mechanical and fluid systems
Compact Vibration Damper
Structural vibrations frequently need to be damped to prevent damage to a structure. To accomplish this, a standard linear damper or elastomeric-suspended masses are used. The problem associated with a linear damper is the space required for its construction. For example, if the damper's piston is capable of three inches of movement in either direction, the connecting shaft and cylinder each need to be six inches long. Assuming infinitesimally thin walls, connections, and piston head, the linear damper is at least 12 inches long to achieve +/-3 inches of movement. Typical components require 18+ inches of linear space. Further, tuning this type of damper typically involves fluid changes, which can be tedious and messy. Masses suspended by elastomeric connections enable even less range of motion than linear dampers. The NASA invention is for a compact and easily tunable structural vibration damper. The damper includes a rigid base with a slider mass for linear movement. Springs coupled to the mass compress in response to the linear movement along either of two opposing directions. A rack-and-pinion gear coupled to the mass converts the linear movement to a corresponding rotational movement. A rotary damper coupled to the converter damps the rotational movement. To achieve +/- 3 inches of movement, this design requires slightly more than six inches of space.
materials and coatings
Polyamides are polymers that are similar to polyimides (another polymer that has been developed for use in aerogels). However, because the amide link is a single chain while the imide link is a ring structure, polyamide aerogels can be made less stiff than polyimides, even though a similar fabrication process is used. The precursor materials can be made from any combination of diamine and diacid chloride. Furthermore, NASA Glenn researchers have found methods for using combinations of diamines and disecondary amines to produce polyamide aerogels with tunable glass transition temperatures, for greater control of features such as flexibility or water-resistance. In the first step of the fabrication process, an oligomeric solution is produced that is stable and can be prepared and stored indefinitely as stock solutions prior to cross-linking. This unique feature allows for the preparation and transport of tailor-made polyamide solutions, which can later be turned into gels via the addition of a small amount of cross-linker. When the cross-linking agent is added, the solution can be cast in a variety of forms such as thin films and monoliths. To remove the solvent, one or more solvent exchanges can be performed, and then the gel is subjected to supercritical drying to form a polyamide aerogel. NASA Glenn's polyamide aerogels can be fully integrated with the fabrication techniques and products of polyimide aerogel fabrication, so hybrid materials which have the properties of both classes are easily prepared. As the first aerogels to be composed of cross-linked polyamides, these materials combine flexibility and transparency in a way that sets them apart from all other polymeric aerogels.
Smart Skin for Composite Aircraft
When a lightning leader propagates through the atmosphere in the vicinity of an aircraft, the lightning electromagnetic emissions generated from the moving electrical charge will radiate the aircraft surface before the actual strike to the aircraft can occur. As the lightning leader propagates closer to the aircraft, the radiated emissions at the aircraft will grow stronger. By design, the frequency bandwidth of the lightning radiated is in the range for SansEC resonance. Hence the SansEC coil will be passively powered by the external oscillating magnetic field of the lightning radiated emission. The coil will resonate and generate its own oscillating magnetic and electric fields. These fields generate so-called Lorentz forces that influence the direction and momentum of the lightning attachment and thereby deflect/spread where the strike entry and exit points/damage occurs on the aircraft.
Sensory Metallic Materials
While almost all advancements in nondestructive evaluation (NDE) focus on improving the NDE equipment and techniques, any testing is inherently limited by the response of the materials being tested. This technology seeks to improve the response of the material itself by embedding shape memory alloy (SMA) particles in the metallic structural alloy in a manner that does not compromise the structural integrity of the material. These SMA particles undergo a martensitic phase change (crystallographic change) in response to strain (e.g., a crack tip causing local deformation). The phase change produces an acoustic emission and a change in magnetic properties that can easily be detected and monitored, providing a means for enhanced NDE. The advantage is either that (1) the technology makes available existing NDE techniques that were not applicable before because of the type of structural material being used (the particles add new physics to the base structure) or (2) the technology enhances NDE because the SMA particles create conditions that are easier to detect damage relative to the equivalent level of damage in a structure without particles.
Fiber-Metal Laminate Manufacturing Technique
Fiber-Metal Laminates (FMLs) are composite materials that consist of conventional fiber reinforced plastics with the addition of a metal component, typically a foil or mesh layer(s). The metal component offers the advantage of incorporating metal-like properties to the composite construction. While a range of potential advantages and applications have been discussed for FMLs, the primary application to date has been for aircraft structures, with one potential advantage being the lightning strike protection (LSP) offered by the improved electrical conductivity. As aircraft construction has moved to composite structures, there has been an increasing need for such conductive composites. Similarly, with increasing use of composites for other large structures, e.g. wind turbines, there are an increasing number of potential applications for lightning strike protection materials. Other advantages of FML are improved impact and fire resistance. This innovation provides a method for making FML materials that incorporate nanotube reinforcement. The method involves the use of RF plasma spray to directly form and deposit nanotube materials onto fibers/fabrics, which can then be manufactured into composite structures by infiltrating the fiber with resin, and consolidating the structure via autoclave processing or via the use Vacuum Assisted Resin Transfer Molding (VARTM) composite manufacturing methods. Nanotubes incorporated into the structure in this manner can be of several types, for example boron nitride or carbon nanotubes. The objective of this innovation is to incorporate the nanotube materials in the FML in order to improve the mechanical properties.
Ultrasonic Stir Welding
Ultrasonic Stir Welding is a solid state stir welding process, meaning that the weld work piece does not melt during the welding process. The process uses a stir rod to stir the plasticized abutting surfaces of two pieces of metallic alloy that forms the weld joint. Heating is done using a specially designed induction coil. The control system has the capability to pulse the high-power ultrasonic (HPU) energy of the stir rod on and off at different rates from 1-second pulses to 60-millisecond pulses. This pulsing capability allows the stir rod to act as a mechanical device (moving and stirring plasticized nugget material) when the HPU energy is off, and allowing the energized stir rod to transfer HPU energy into the weld nugget (to reduce forces, increase stir rod life, etc.) when the HPU energy is on. The process can be used to join high-melting-temperature alloys such as titanium, Inconel, and steel.
power generation and storage
Optimum Solar Conversion Cell Configurations
A solar cell manufactured from this new optical fiber has photovoltaic (PV) material integrated into the fiber to enable electricity generation from unused light, including non-visible portions of the spectrum and visible light not transmitted to a lighting application. These new solar cells are based around cylindrical optical fibers, providing two distinct advantages over the flat panels that lead to increased efficiency. The core fiber, used to transmit light, can be adjusted to increase or decrease the amount of available light that is transmitted to the lighting application at any point in real time. This invention can be applied wherever optical concentrators are used to collect and redirect incident light. Wavelengths as large as 780 nanometers (nm) can be used to drive the conversion process. This technology has very low operating costs and environmental impacts (in particular, no greenhouse gas emissions). The fiber uses low-cost polymer materials. It is lightweight and flexible, and can be manufactured using low-cost solution processing techniques. Such multifunctional materials have great potential for the future of solar and photovoltaic devices. They will enable new devices that are small and lightweight that can be used without connection to existing electrical grids.