Bnnt, LLC

Jefferson Science Associates, LLC

Jonathan C Stevens

Kevin Carl Jordan

Michael W Smith

R Roy Whitney

Thomas G Dushatinski

Thomas W Henneberg

Clay F Huff

Lyndsey R Scammell

Alex I Wixtrom

Diego Pedrazzoli

Gary S Huvard

Kevin C Jordan

Roy R Whitney

Diego Pedrazolli

Thermal interface materials may be enhanced through the dispersion of refined boron nitride nanotubes (BNNTs) into a polymer matrix material and one or more microfillers. A refined BNNT material may be formed by reducing free boron particle content from an as-synthesized BNNT material, and in some embodiments reducing h-BN content. Reducing these species improves the thermal conductivity of the BNNTs. Refined BNNTs may be deagglomerated to reduce the size and mass of BNNTs in agglomerations when the deagglomerated BNNT material is dispersed into a target polymer matrix material. The deagglomerated BNNT material may be lyophilized prior to dispersion in the matrix material, to retain the deagglomeration benefit following return to solid state. The surface of the deagglomerated BNNT material may be modified, with one or more functional groups that improve dispersibility and heat transfer in the target polymer matrix material.

BNNT thermal management material for high-power systems

The structural integrity and viscoelastic performance of boron nitride nanotube (BNNT) materials may be improved through forming a compressed BNNT buckyweave. The BNNT buckyweave may be formed from a BNNT buckypaper having a bulk nanotube alignment (partial alignment) that may be maintained when forming the BNNT buckyweave, and compression may be parallel to and/or perpendicular to the partial alignment. The BNNT material may be viscoelastically-enhanced through, e.g., selection of synthesized BNNT material, impurity removal/reduction, BNNT alignment, isotopically enhancement, and compression relative to alignment. BNNT buckyweave s are introduced. The present approach provides viscoelastic behavior over temperatures from near absolute zero to near 1900 K. The transport of phonons along the BNNT molecules may be enhanced by utilizing isotopically enhanced BNNTs.

Boron nitride nanotube vibration damping optimization

High quality, catalyst-free boron nitride nanotubes (BNNTs) that are long, flexible, have few wall molecules and few defects in the crystalline structure, can be efficiently produced by a process driven primarily by Direct Induction. Secondary Direct Induction coils, Direct Current heaters, lasers, and electric arcs can provide additional heating to tailor the processes and enhance the quality of the BNNTs while reducing impurities. Heating the initial boron feed stock to temperatures causing it to act as an electrical conductor can be achieved by including refractory metals in the initial boron feed stock, and providing additional heat via lasers or electric arcs. Direct Induction processes may be energy efficient and sustainable for indefinite period of time. Careful heat and gas flow profile management may be used to enhance production of high quality BNNT at significant production rates.

Boron nitride nanotube synthesis via direct induction

Boron nitride nanotube (BNNT) material can be placed in large volume configurations such as needed for cryopumps, high surface area filters, scaffolding for coatings, transition radiation detectors, neutron detectors, and similar systems where large volumes may range from cubic millimeters to cubic meters and beyond. The technology to secure the BNNT material includes creating a scaffold of a material acceptable to the final system such as stainless steel wires for a cryopump. The BNNTs can be arranged in the scaffold by freeze drying, filtration technologies, conformal surface attachment and BNNT 'glue' where the as-synthesized BNNT material has been partially purified or fully purified and dispersed in a dispersant.

Boron nitride nanotube materials for cryopumps and other large volume configurations

Disclosed herein are processes for purifying as-synthesized boron nitride nanotube (BNNT) material to remove impurities of boron, amorphous boron nitride (a-BN), hexagonal boron nitride (h-BN) nanocages, h-BN nanosheets, and carbon-containing compounds. The processes include heating the BNNT materials at different temperatures in the presence of inert gas and a hydrogen feedstock or in the presence of oxygen.

Boron nitride nanotube purification

Described herein are apparatus, systems, and methods for the continuous production of BNNT fibers, BNNT strands and BNNT initial yarns having few defects and good alignment. BNNTs may be formed by thermally exciting a boron feedstock in a chamber in the presence of pressurized nitrogen. BNNTs are encouraged to self-assemble into aligned BNNT fibers in a growth zone, and form BNNT strands and BNNT initial yarns, through various combinations of nitrogen gas flow direction and velocities, heat source distribution, temperature gradients, and chamber geometries.

Continuous boron nitride nanotube fibers

Thermoresponsive composite switch (TRCS) membranes for ion batteries include a porous scaffolding providing ion channels and a thermoresponsive polymer coating. Boron nitride nanotube (BNNT)/polymer composite TRCS membrane embodiments are preferable due to unique BNNT properties. A BNNT scaffold coated with one or more polymers may form a composite separator with tunable porosity (porosity level and pore size distribution), composition, wettability, and superior electronic isolation, oxidative/reduction resistance, and mechanical strength. The BNNT/polymer composite TRCS membrane optimizes the performance of ion batteries with tunable separator thicknesses that may be under 5 &#x3bc;&#x3b9;&#x3b7;. Nano-scale porosity with thin separator thicknesses improves the charge density of the battery. Nano-scale architecture allows for reversible localized switching on the nano scale, in proximity to thermally stressed ion substrates. Polymer thermal expansion will decrease porosity at temperatures approaching the thermal runaway point. The BNNT polymers composite therefore functions as a TRCS.

Nano-porous BNNT composite with thermal switching for advanced batteries

BNNT thermal management materials for high-power systems

As disclosed herein, the viscoelastic performance of boron nitride nanotube (BNNT) materials may be enhanced and made into useful formats by utilizing purified BNNTs, aligned BNNTs, isotopically enhanced BNNTs, and density controlled BNNT material. Minimizing the amounts of boron particles, a-BN particles, and h-BN nanocages, and optimizing the h-BN nanosheets has the effect of maximizing the amount of BNNT surface area present that may interact with BNNTs themselves and thereby create the nanotube-to-nanotube friction that generates the viscoelastic behavior over temperatures from near absolute zero to near 1900 K. Aligning the BNNT molecular strands with each other within the BNNT material also generates enhanced friction surfaces. The transport of phonons along the BNNT molecules may be further enhanced by utilizing isotopically enhanced BNNTs.

Boron nitride nanotube vibration damping

Transition radiation from nanotubes, nanosheets, and nanoparticles and in particular, boron nitride nanomaterials, can be utilized for the generation of light. Wavelengths of light of interest for microchip lithography, including 13.5 nm (91.8 eV) and 6.7 nm (185 eV), can be generated at useful intensities, by transition radiation light sources. Light useful for monitoring relativistic charged particle beam characteristics such as spatial distribution and intensity can be generated.

Transition radiation light sources

Described herein are processes and apparatus for the large-scale synthesis of boron nitride nanotubes (BNNTs) by induction-coupled plasma (ICP). A boron-containing feedstock may be heated by ICP in the presence of nitrogen gas at an elevated pressure, to form vaporized boron. The vaporized boron may be cooled to form boron droplets, such as nanodroplets. Cooling may take place using a condenser, for example. BNNTs may then form downstream and can be harvested.

Growing community of inventors

Williamsburg, VA, United States of America

Jonathan C Stevens