Highly Porous and Mechanically Strong Ceramic Oxide Aerogels

These materials provide improved environmental durability and elasticity for aerospace and terrestrial applications.

NASA's Glenn Research Center (GRC) has developed and produced ultra-lightweight polymer cross-linked aerogels (X-Aerogels). These mechanically robust, highly porous, low-density materials are three times denser than native aerogels, but more than 100 times stronger. Aerogels are ultra-lightweight glass foams with extremely small pores (on the order of 10 to 50 nanometers). These materials are extremely good thermal insulators, with R values ranging from 2 to 10 times higher than polymer foams. Unlike multilayer insulation, aerogels do not require a high vacuum to maintain their low thermal conductivity, and can function as good thermal insulators at ambient pressure. In addition, they are good electrical insulators and have low refractive indices, both approaching values close to air. Aerogels are also excellent vibration-damping materials. Traditional aerogels, however, suffer fragility and poor environmental durability.

Posted in: Briefs, Materials, Ceramics, Conductivity, Foams, Lightweight materials, Materials properties, Polymers

Asymmetric Dielectric Elastomer Composite Material

This material has applications in artificial muscle and hearts, physical therapy/rehab devices, morphing aircraft, robotics, and sensors.

This electronic active material converts a voltage input to a mechanical force and mechanical displacement output. As compared to prior dielectric elastomer (DE) systems, the material has reduced electrode spacing, which lowers significantly the required operating voltage. In addition, the inclusion of a combination of conducting and/or non-conducting reinforcing fibers greatly enhances the strength of the material, without weight penalty.

Posted in: Briefs, Materials, Voltage regulators, Composite materials, Elastomers, Fibers

Method of Creating Micro-Scale Silver Telluride Grains Covered with Bismuth Nanoparticles

Potential applications include power generation and waste heat recovery, and refrigeration and cooling.

NASA Langley Research Center has developed a novel thermoelectric (TE) material utilizing micro-scale silver telluride grains covered with bismuth nanoparticles. These materials have unique advantages in directly converting any level of thermal energy into electrical power and solid-state cooling by a reverse mode. Although thermoelectric devices are regarded advantageously with their high reliability, their lack of moving parts, and their ability to scale to any sizes, the devices’ energy conversion efficiency remains generally poor.

Posted in: Briefs, Materials, Electric power, Thermodynamics, Materials properties, Nanomaterials

Polyimides Derived from Novel Asymmetric Benzophenone Dianhydrides

NASA's Glenn Research Center invites companies to license or establish partnerships to develop its patented high-temperature, low-melt imide resins for fabrication of automotive components. Produced by a solvent-free melt process, these resins exhibit high glass transition temperatures (Tg = 370 to 400 °C), low melt viscosities (10 to 30 poise), long pot-life (1 to 2 hours), and can be easily processed by low-cost RTM and vacuum-assisted resin transfer molding (VARTM). These RTM resins melt at 260 to 280 °C, and can be cured at 340 to 370 °C in 2 hours without releasing any harmful volatile compounds.

Posted in: Briefs, Materials, Heat resistant materials, Materials properties, Resins

Nanotubular Toughening Inclusions

This technology is used for making stable resin dispersions and composite plastic films, and for standard polymer melt processing.

NASA's Langley Research Center has developed an extensive technology portfolio on novel methods for effective dispersion of carbon nanotubes (CNTs) in polymers. The technology portfolio extends from making stable dispersions of CNTs in polymer resins to processes for making composite CNT/polymer films and articles. The technologies apply to a range of polymer types, enable low or high CNT loadings as needed, and can be used with a variety of standard polymer processing methods, including melt processing. Currently, the technology is being used commercially for electrically conductive polymer films for components in electronic printers and copiers.

Posted in: Briefs, Materials, Fabrication, Composite materials, Nanomaterials, Polymers

Electric Field Activated Shape Memory Polymer Composite

Applications include intelligent medical devices, smart armor, turbine blade stabilization, and aircraft wing stabilization.

NASA’s Langley Research Center has developed a novel shape memory polymer (SMP) made from composite materials for use in morphing structures. In response to an external stimulus such as a temperature change or an electric field, the thermosetting material changes shape, but then returns to its original form once conditions return to normal. Through a precise combination of monomers, conductive fillers, and elastic layers, the NASA polymer matrix can be triggered by two effects — Joule heating and dielectric loss — to increase the response. The new material remedies the limitations of other SMPs currently on the market; namely, the slow stimulant response times, the strength inconsistencies, and the use of toxic epoxies that may complicate manufacturing. NASA has developed prototypes and now seeks a partner to license the technology for commercial applications.

Posted in: Briefs, Materials, Electric power, Product development, Heat treatment, Composite materials, Polymers, Smart materials

Strain-Detecting Composite Materials

These materials can be used in aerospace vehicles and aircraft, or in any application where monitoring total overload or localized strain is critical.

NASA Langley Research Center has developed a metallic material that can be embedded into structural alloys to enhance nondestructive evaluation (NDE) of a structure. Current NDE tools, such as eddy current probes and others, can have some difficulties detecting small flaws in certain materials and structures. Also, using them can be costly, time-consuming, and labor-intensive, often resulting in significant downtime in the case of examination of machinery and vehicles. This innovation is to embed particles that react to strain with easily detected acoustic emissions and change in magnetic properties.

Posted in: Briefs, Materials, On-board diagnostics, On-board diagnostics (OBD), Alloys, Composite materials, Non-destructive tests, Test equipment and instrumentation

Compositions Comprising Nickel-Titanium, Methods of Manufacture Thereof, and Articles Comprising the Same

These solid lubricant coatings provide reduced friction and wear to any lightly loaded sliding mechanism operating from cryogenic to 650 °C.

NASA's Glenn Research Center has developed high-temperature solid lubricant materials suitable for foil gas bearings that enable the commercialization of a broad array of revolutionary oil-free gas turbines, compressors, blowers, motors, and other rotating machines that can operate from cryogenic to redhot temperatures. These tribological (friction and wear) coatings and composite powder metallurgy material innovations have immediate and proven spinoff potential for high-temperature steam turbine control valves, exhaust gas recirculation (EGR) valves, articulating ducts and piping joints, and other industrial and aerospace applications.

Posted in: Briefs, Materials, Lubricants, Powder metallurgy, Nickel, Titanium, Tribology, Bearings

Preparation of Metal Nanowire Decorated Carbon Allotropes

This technology produces materials for a variety of applications in electronics, communications, catalysis, and optics.

NASA's Langley Research Center has created a new class of materials based on depositing nanometer-sized metal particles onto carbon allotropes. The method is scalable and relatively simple, and allows for control over the size and distribution of the metal particles in the substrate, adjusting the surface area to optimize specific thermal or electrical properties of the material. One promising nanocomposite material created consists of multi-walled carbon nanotubes (MWCNTs) decorated with metal particles dispersed in a polymer matrix. Ribbons, tubes, and moldings of the nanocomposite were found to have novel intrinsic electrical characteristics that enable tunable dielectric constants with low loss factors. The decoupling and independent control of the two fundamental parameters offer a class of materials with the potential for finely tailored electronic properties. The novel methods enable materials that show promise for a variety of applications in electronics, communications, catalysis, and optics.

Posted in: Briefs, Materials, Product development, Fabrication, Composite materials, Metals, Nanomaterials

In Situ Mechanical Property Measurements of Amorphous Carbon-Boron Nitride Nanotube Nanostructures

Utilizing the full mechanical capabilities of individual nanotubes is a primary research goal in nanotube reinforced nanocomposite materials. Practical use of these nanomaterials requires creating stable and strong linkages between nanotubes without sacrificing their mechanical advantage. Cross-linking between shells via electron beam irradiation and application of large compressive forces have been studied and offer a viable approach to improve tube-to-tube load transfer and hence, mechanical properties. However, these approaches result in unwanted mechanical degradation and have limitations in scale-up for their applications to macroscopic nanocomposite materials.

Posted in: Briefs, Materials, Architecture, Composite materials, Nanomaterials

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