United States of America As Represented by the Administrator of Nasa

National Institute of Aerospace Associates

The United States of America As Represented by the Administrator of the

Jefferson Science Associates, LLC

Jin Ho Kang

Cheol Park

Godfrey Sauti

Sharon E Lowther

Joycelyn S Harrison

Robert G Bryant

Emilie J Siochi

Peter T Lillehei

Sheila Ann Thibeault

Michael W Smith

Keith L Gordon

Catharine C Fay

Luke Gibbons

Kevin Carl Jordan

Jae-Woo Kim

Travis L Turner

Tian-Bing Xu

Ronald K Penner

Sharon Lowther

Glen C King

Larry T Taylor

Xiaoning Jiang

Sang-Hyon Chu

Kristopher E Wise

Lei Zuo

John-Andrew S Hocker

Chase Taylor

Iseley Marshall

Negin Nazem

Emille J Siochi

Sheila A Thibeault

Joycelyn S Harrisson

Provided are methods of preparing an electrically activated shape memory polymer composite capable of thermal shape reformation using electric power to heat the composite through its matrix glass transition temperature. The methods may include providing a polymer matrix component comprising a diglycidyl ether resin and at least one curing agent, adding into the polymer matrix component at least one nano-filler component, sonication and mixing the polymer matrix component and the nano-filler component to form a mixture, curing the mixture under curing conditions, and laminating the cured mixture with at least one elastic laminated layer.

Method for preparing an electrically-activated shape memory polymer composite

A lightweight flexible BNNT mat or fabric provides improved thermal stability and shielding capabilities under a hypersonic thermal flux. The BNNT mat reduces the stagnation temperature and maintains a low regression rate. An in-situ passivation layer may be formed on the BNNT mat or fabric under high thermal flux. The passivation layer minimizes or prevents penetration of the atmosphere (air or gas) as well as heat and radiation through the thickness of the BNNT material, and it effectively diffuses heat throughout the mat or fabric laterally and radially to minimize localized excessive heat. A BNNT mat according to the present disclosure may also efficiently transfer heat from the BNNT material via radiation due to the high thermal emissivity (0.92) of the BNNT material.

In-situ passivation and insulation layer for a flexible thermal protection system (FTPS)

The invention consists of radiation shielding materials for shielding in the most structurally robust combination against galactic cosmic radiation (GCR), neutrons, and solar energetic particles (SEP). Materials for vehicles, space structures, habitats, landers, rovers, and spacesuits must possess functional characteristics of radiation shielding, thermal protection, pressure resistance, and mechanical durability. The materials are tailored to offer the greatest shielding against GCR, neutrons, and SEP in the most structurally robust combination, also capable of shielding against micrometeoriod impact. The boron nitride nanotube (BNNT) is composed entirely of low Z atoms (boron and nitrogen). Some of the materials included in this invention are: boron nitride (BN) platelets, hot pressed BN, BNNT, BN particle containing resins, BN nanofiber containing resins, carbon fiber reinforced BN containing resins, BNNT containing resins, and hydrogenated BN and BNNT, hydrogen stored BN and BNNT, high hydrogen containing polymer or ceramic matrices, and a combination of these.

Radiation shielding materials containing hydrogen, boron and nitrogen

Formation of a boron nitride nanotube nanocomposite film by combining a boron nitride nanotube solution with a matrix such as a polymer or a ceramic to form a boron nitride nanotube/polyimide mixture and synthesizing a boron nitride nanotube/polyimide nanocomposite film as an electroactive layer.

Methods of manufacturing energy conversion materials fabricated with boron nitride nanotubes (BNNTs) and BNNT polymer composites

A novel radiation hardened chip package technology protects microelectronic chips and systems in aviation/space or terrestrial devices against high energy radiation. The proposed technology of a radiation hardened chip package using rare earth elements and mulitlayered structure provides protection against radiation bombardment from alpha and beta particles to neutrons and high energy electromagnetic radiation.

Radiation hardened microelectronic chip packaging technology

Systems, methods, and devices of the various embodiments provide pyroelectric sandwich thermal energy harvesters. In the various embodiment pyroelectric sandwich thermal energy harvesters, generated electrical energy may be stored in a super-capacitor/battery as soon as it is generated. The various embodiment pyroelectric sandwich thermal energy harvesters may harvest electrical energy from any environment where temperature variations occur. The various embodiment pyroelectric sandwich thermal energy harvesters may be power sources for space equipment and vehicles in space and/or on earth, as well as the for wireless sensor networks, such as health monitoring systems of oil pipes, aircraft, bridges, and buildings.

Pyroelectric sandwich thermal energy harvesters

Disclosed is a single wall carbon nanotube (SWCNT) film electrode (FE), all-organic electroactive device systems fabricated with the SWNT-FE, and methods for making same. The SWCNT can be replaced by other types of nanotubes. The SWCNT film can be obtained by filtering SWCNT solution onto the surface of an anodized alumina membrane. A freestanding flexible SWCNT film can be collected by breaking up this brittle membrane. The conductivity of this SWCNT film can advantageously be higher than 280 S/cm. An electroactive polymer (EAP) actuator layered with the SWNT-FE shows a higher electric field-induced strain than an EAP layered with metal electrodes because the flexible SWNT-FE relieves the restraint of the displacement of the polymeric active layer as compared to the metal electrode. In addition, if thin enough, the SWNT-FE is transparent in the visible light range, thus making it suitable for use in actuators used in optical devices.

Methods for making an electroactive device fabricated with a nanotube film electrode

Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nontubes (CNTs), graphites, or their combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mates of BNNTs are uses as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also uses as reinforcing inclusions combining with other polymer matrices to create composite layer like typical reinforcing fibers such as Kevlar&#xae;, Spectra&#xae;, ceramics and metals. Enhanced wear resistance and prolonged usage time, even under harsh conditions, are achieved by adding boron nitride nanomaterials because both hardness and toughness are increased. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800&#xb0; C. in air. Boron nitride based composite materials are useful as strong structural materials for anti-micrometeorite layers for spacecraft and space suits, ultra strong tethers, protective gear for the human body as well as for vehicles, helmets, shields and safety suits/helmets for industry.

High kinetic energy penetrator shielding and high wear resistance materials fabricated with boron nitride nanotubes (BNNTS) and BNNT polymer composites

Some implementations provide a device (e.g., solar panel) that includes an active layer and a solar absorbance layer. The active layer includes a first N-type layer and a first P-type layer. The solar absorbance layer is coupled to a first surface of the active layer. The solar absorbance layer includes a polymer composite. In some implementations, the polymer composite includes one of at least metal salts and/or carbon nanotubes. In some implementations, the active layer is configured to provide the photovoltaic effect. In some implementations, the active layer further includes a second N-type layer and a second P-type layer. In some implementations, the active layer is configured to provide the thermoelectric effect. In some implementations, the device further includes a cooling layer coupled to a second surface of the active layer. In some implementations, the cooling layer includes one of at least zinc oxides, indium oxides, and/or carbon nanotubes.

Solar radiation control and energy harvesting film

Multifunctional Boron Nitride nanotube-Boron Nitride (BN&#x2014;BN) nanocomposites for energy transducers, thermal conductors, anti-penetrator/wear resistance coatings, and radiation hardened materials for harsh environments. An all boron-nitride structured BN&#x2014;BN composite is synthesized. A boron nitride containing precursor is synthesized, then mixed with boron nitride nanotubes (BNNTs) to produce a composite solution which is used to make green bodies of different forms including, for example, fibers, mats, films, and plates. The green bodies are pyrolized to facilitate transformation into BN&#x2014;BN composite ceramics. The pyrolysis temperature, pressure, atmosphere and time are controlled to produce a desired BN crystalline structure. The wholly BN structured materials exhibit excellent thermal stability, high thermal conductivity, piezoelectricity as well as enhanced toughness, hardness, and radiation shielding properties. By substituting with other elements into the original structure of the nanotubes and/or matrix, new nanocomposites (i.e., BCN, BCSiN ceramics) which possess excellent hardness, tailored photonic bandgap and photoluminescence, result.

Multi-functional BN&#x2014;BN composite

Provided is an electrically activated shape memory polymer composite capable of thermal shape reformation using electric power to heat the composite through its matrix glass transition temperature. The composite includes an adaptable polymer matrix component using a diglycidyl ether resin, at least one substantially well-dispersed conductive or magnetic nano-filler component, and at least one elastic, laminated layer. Also provided are methods of preparing the composite and methods of activating the composite. A shape reformation of the composite is triggered by applying an electric field at DC and/or at a frequency above about 1 &#x3bc;Hz for a sufficient time.

Electric field activated shape memory polymer composite

Metamaterials or artificial negative index materials (NIMs) have generated great attention due to their unique and exotic electromagnetic properties. One exemplary negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly (benzimidazole) (PBI). The doped PBI showed a negative dielectric constant at megahertz (MHz) frequencies due to its reduced plasma frequency and an induction effect. The magnitude of the negative dielectric constant and the resonance frequency were tunable by doping concentration. The highly doped PBI showed larger absolute magnitude of negative dielectric constant at just above its resonance frequency than the less doped PBI.

Negative dielectric constant material based on ion conducting materials

Nanotube film electrode and an electroactive device fabricated with the nanotube film electrode and methods for making same

Some implementations provide a composite material that includes a first material and a second material. In some implementations, the composite material is a metamaterial. The first material includes a chiral polymer (e.g., crystalline chiral helical polymer, poly-&#x3b3;-benzyl-L-glutamate (PBLG), poly-L-lactic acid (PLA), polypeptide, and/or polyacetylene). The second material is within the chiral polymer. The first material and the second material are configured to provide an effective index of refraction value for the composite material of 1 or less. In some implementations, the effective index of refraction value for the composite material is negative. In some implementations, the effective index of refraction value for the composite material of 1 or less is at least in a wavelength of one of at least a visible spectrum, an infrared spectrum, a microwave spectrum, and/or an ultraviolet spectrum.

Doped chiral polymer metamaterials

A novel method to develop highly conductive functional materials which can effectively shield various electromagnetic effects (EMEs) and harmful radiations. Metallized nanotube polymer composites (MNPC) are composed of a lightweight polymer matrix, superstrong nanotubes (NT), and functional nanoparticle inclusions. MNPC is prepared by supercritical fluid infusion of various metal precursors (Au, Pt, Fe, and Ni salts), incorporated simultaneously or sequentially, into a solid NT-polymer composite followed by thermal reduction. The infused metal precursor tends to diffuse toward the nanotube surface preferentially as well as the surfaces of the NT-polymer matrix, and is reduced to form nanometer-scale metal particles or metal coatings. The conductivity of the MNPC increases with the metallization, which provides better shielding capabilities against various EMEs and radiations by reflecting and absorbing EM waves more efficiently. Furthermore, the supercritical fluid infusion process aids to improve the toughness of the composite films significantly regardless of the existence of metal.

Growing community of inventors

Newport News, VA, United States of America

Jin Ho Kang