United States of America As Represented by the Administrator of Nasa

National Institute of Aerospace Associates

Yi Lin

John W Connell

Emilie J Siochi

Jae-Woo Kim

Kristopher E Wise

Christopher J Wohl, Jr

Russell A Wincheski

Dennis C Working

John W Hopkins

Brandon Moitoso

Joseph G Smith, Jr

Sayata Ghose

Kent A Watson

Jereme R Doss

Caroline J Campbell

Jae Woo Kim

Lilly Lynn Balderson

Devon Beck

Allison M Crow

William T Kim

Michael R Funk

In an illustrative example, one or more coating formulations may be used and may have characteristics useful in different situations. During evaluations, a plurality of coating formulations comprising epoxy resins and diamine hardeners were prepared and evaluated with regards to impact ice adhesion strength and durability. Alone, such coating formulations provided a significantly reduced impact ice adhesion strength as compared to uncoated aluminum and/or stainless steel surfaces. However, a durability of the coatings, when applied to aluminum or stainless steel surfaces, was insufficient to be considered for use on external aircraft surfaces. By including nano-sized and/or micro-sized particles as additives to the coating formulations, resulted in improved durability without significantly reducing ice adhesion performance of the resin base.

Durable contamination resistant coatings

Systems, methods, and devices of the various embodiments provide for the creation of holey graphene meshes (HGMs) and composite articles including HGMs. Various embodiments provide solvent-free methods for creating arrays of holes on holey graphene-based articles formed from dry compression (such as films, discs, pellets), thereby resulting in a HGM. In further embodiments, a HGM can used as part of a composite, such as by: 1) embedding a HGM into another matrix material such as carbon, polymer, metals, metal oxides, etc; and/or (2) the HGM serving as a matrix by filling the holes of the HGM or functionalizing the HGM body with another one or more materials. In various embodiments, HGM can also be made as a composite itself by creating holes on dry-compressed articles pre-embedded with one or more other materials.

Holey graphene mesh and solvent-free manufacturing and composites thereof

A method allows for preparation of CNT nanocomposites having improved mechanical, electrical and thermal properties. Structured carbon nanotube forms such as sheet, yarn, and tape are modified with &#x3c0;-conjugated conductive polymers, including polyaniline (PANT), fabricated by in-situ polymerization. The PANI modified CNT nanocomposites are subsequently post-processed to improve mechanical properties by hot press and carbonization.

Polyaniline/carbon nanotube sheet nanocomposites

Various embodiments provide random copolyimides that may possess the mechanical, thermal, chemical and optical properties associated with polyimides yet achieve a low energy surface. In various embodiments, the copolyimides may be prepared using a minor amounts of a diamino terminated fluorinated alkyl ether oligomer and a diamino terminated siloxane oligomer. The various embodiments include processes for making the copolyimides containing fluorine and silicon surface modifying agents and anisotropic coatings and articles of manufacture from them. Thus the coatings and articles of manufacture made with the copolyimides of the various embodiments may be characterized as having an anisotropic fluorine and silicon composition and low surface energy.

Synthesis of copolyimides containing fluorine and silicon surface modifying agents

A method allows for preparation of CNT nanocomposites having improved mechanical, electrical and thermal properties. Structured carbon nanotube forms such as sheet, yarn, and tape are modified with &#x3c0;-conjugated conductive polymers, including polyaniline (PANI), fabricated by in-situ polymerization. The PANI modified CNT nanocomposites are subsequently post-processed to improve mechanical properties by hot press and carbonization.

Methods for forming holey carbon allotropes and graphene nanomeshes are provided by the various embodiments. The various embodiments may be applicable to a variety of carbon allotropes, such as graphene, graphene oxide, reduced graphene oxide, thermal exfoliated graphene, graphene nanoribbons, graphite, exfoliated graphite, expanded graphite, carbon nanotubes (e.g., single-walled carbon nanotubes, double-walled carbon nanotubes, few-walled carbon nanotubes, multi-walled carbon nanotubes, etc.), carbon nanofibers, carbon fibers, carbon black, amorphous carbon, fullerenes, etc. The methods may produce holey carbon allotropes without the use of solvents, catalysts, flammable gas, additional chemical agents, or electrolysis to produce the pores (e.g., holes, etc.) in the carbon allotropes. In an embodiment, a carbon allotrope may be heated at a working window temperature for a working period of time to create holes in the carbon allotrope.

Single-step, solvent-free, catalyst-free preparation of holey carbon allotropes

A method for joining or repairing boron nitride nanotubes (BNNTs). In joining BNNTs, the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures. In repairing BNNTs, the damaged site of the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures at the damage site.

Amorphous carbon-boron nitride nanotube hybrids

A scalable method allows preparation of bulk quantities of holey carbon allotropes with holes ranging from a few to over 100 nm in diameter. Carbon oxidation catalyst nanoparticles are first deposited onto a carbon allotrope surface in a facile, controllable, and solvent-free process. The catalyst-loaded carbons are then subjected to thermal treatment in air. The carbons in contact with the carbon oxidation catalyst nanoparticles are selectively oxidized into gaseous byproducts such as CO or CO, leaving the surface with holes. The catalyst is then removed via refluxing in diluted nitric acid to obtain the final holey carbon allotropes. The average size of the holes correlates strongly with the size of the catalyst nanoparticles and is controlled by adjusting the catalyst precursor concentration. The temperature and time of the air oxidation step, and the catalyst removal treatment conditions, strongly affect the morphology of the holes.

Bulk preparation of holey graphene via controlled catalytic oxidation

A new method is disclosed for the exfoliation of hexagonal boron nitride into mono- and few-layered nanosheets (or nanoplatelets, nanomesh, nanoribbons). The method does not necessarily require high temperature or vacuum, but uses commercially available h-BN powders (or those derived from these materials, bulk crystals) and only requires wet chemical processing. The method is facile, cost efficient, and scalable. The resultant exfoliated h-BN is dispersible in an organic solvent or water thus amenable for solution processing for unique microelectronic or composite applications.

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Yorktown, VA, United States of America

Yi Lin