Abstract: A lightweight radiation shielding material. A carbon nanotube forest is embedded in a matrix comprising nanoparticulates, such as nanoparticles, carbon nanotubes, or graphene nanosheets. The nanoparticulates can be low atomic number (low-Z) or high atomic number (high-Z). The matrix can be a solidified polymer, epoxy, resin, or ceramic precursor, for example silicon carbide. The radiation shield can shield an object from radio frequency interference (RFI), lightning, electromagnetic interference (EMI), an electromagnetic pulse (EMP), gamma rays, X-rays, neutrons, and/or protons. The nanoforest is disposed on a conductive base with sufficient in-plane electrical conductivity to provide an effective conductive path for currents induced by radiation absorption. The base can be a second nanoforest comprising horizontally-oriented carbon nanotubes, which makes the shield particularly lightweight, as low as 10% of the mass of aluminum that provides equivalent shielding.

Abstract: Methods and apparatuses for continuous, large scale, commercially viable production of nanoforests. A roll-to-roll process passes a flexible substrate, including fibers and fabrics, through a furnace. Precursors are introduced in a growth zone in which a vertical or horizontal nanoforest of nanotubes or nanowires is grown on the substrate. Sensors and actuators with feedback control are provided for parameters such as substrate speed, substrate tension, furnace temperature, precursor flow rate, nanoforest thickness, and nanoforest. The furnace is preferably enclosed for environmental and safety purposes. The feed roll and take-up roll are disposed in housings can be attached to the furnace via airlocks, which enables rapid loading and unloading of the rolls using techniques well known in the industry while maintaining furnace conditions.

Abstract: Methods and apparatuses for continuous, large scale, commercially viable production of nanoforests. A roll-to-roll process passes a flexible substrate, including fibers and fabrics, through a furnace. Precursors are introduced in a growth zone in which a vertical or horizontal nanoforest of nanotubes or nanowires is grown on the substrate. Sensors and actuators with feedback control are provided for parameters such as substrate speed, substrate tension, furnace temperature, precursor flow rate, nanoforest thickness, and nanoforest. The furnace is preferably enclosed for environmental and safety purposes. The feed roll and take-up roll are disposed in housings can be attached to the furnace via airlocks, which enables rapid loading and unloading of the rolls using techniques well known in the industry while maintaining furnace conditions.

Abstract: Methods and apparatuses for continuous, large scale, commercially viable production of nanoforests. A roll-to-roll process passes a flexible substrate, including fibers and fabrics, through a furnace. Precursors are introduced in a growth zone in which a vertical or horizontal nanoforest of nanotubes or nanowires is grown on the substrate. Sensors and actuators with feedback control are provided for parameters such as substrate speed, substrate tension, furnace temperature, precursor flow rate, nanoforest thickness, and nanoforest. The furnace is preferably enclosed for environmental and safety purposes. The feed roll and take-up roll are disposed in housings can be attached to the furnace via airlocks, which enables rapid loading and unloading of the rolls using techniques well known in the industry while maintaining furnace conditions.

Abstract: A reinforcement for increasing the strength and toughness and other properties in both transverse and in-piano directions for a composite material, and methods of manufacture therefor. The reinforcement has a layer of a nanoforest of vertical nanotubes or nanowires and a layer of horizontal nanotubes or nanowires. The reinforcement can be made by rolling a vertical nanoforest to produce a collapsed layer of horizontal nanofubes or nanowires, then growing a vertical nanoforest on the collapsed layer. The reinforcement can be grown directly on fibers which are used to reinforce the composite material, or alternatively Interleaved with layers of those fibers before the composite part is cured. The reinforcement and manufacturing method are compatible with almost any composite material in any shape, including epoxy, polymer, or ceramic matrix composites, or any manufacturing method, including prepreg, wet-layup and matrix film stacking.

Abstract: A method of making a ceramic matrix composite (CMC) part such as armor, in which a mixture, including a preceramic polymer, particles such as ceramic microparticles and/or nanoparticles, and organic compounds such as a surfactant and a solvent, are mixed to form a paste and printed or molded. The part is then cured and densified by polymer infiltration and pyrolysis (PIP) using the preceramic polymer with a varying amount and size of ceramic particles and different temperatures in some of the cycles. The CMC can contain silicon carbide, boron carbide, boron suboxide, alumina, or any other ceramic. The process is compatible with sacrificial materials, enabling the creation of parts with hollow portions or overhangs. The mixture preferably has a high loading of particles, for example between 70 wt % and 90 wt % of the mixture, in order to minimize shrinkage. Curing and pyrolyzing the part can be performed by microwaving.

Abstract: A method of making a ceramic matrix composite (CMC) article by combining a preceramic polymer with one or more sized nanopowders and optional surfactants and/or solvents to form a mixture suitable for 3D printing, depositing the mixture on a mandrel, curing it to form a green body, and pyrolyzing the green body such that the nanocrystalline surface of the CMC article has sufficiently the same surface roughness and figure accuracy of the mandrel to enable the CMC article to be used without further polishing. The mixture can be a paste or slurry that is self supporting and exhibit pseudoplastic rheology. The preceramic polymer is preferably a precursor to SiC, and the nanopowders preferably comprise SiC. The article can be densified by using polymer infiltration pyrolysis, with or without nanoparticles. The curing and pyrolysis of the article can be performed with microwave radiation.

Abstract: A method of making a ceramic matrix composite (CMC) article by combining a preceramic polymer with one or more sized nanopowders and optional surfactants and/or solvents to form a mixture suitable for 3D printing, depositing the mixture on a mandrel, curing it to form a green body, and pyrolyzing the green body such that the nanocrystalline surface of the CMC article has sufficiently the same surface roughness and figure accuracy of the mandrel to enable the CMC article to be used without further polishing. The mixture can be a paste or slurry that is self supporting and exhibit pseudoplastic rheology. The preceramic polymer is preferably a precursor to SiC, and the nanopowders preferably comprise SiC. The article can be densified by using polymer infiltration pyrolysis, with or without nanoparticles. The curing and pyrolysis of the article can be performed with microwave radiation.