High Performance Single-Component (1K) Polysiloxane Topside Coatings

The U.S. Naval Research Laboratory (NRL) has developed a new class of high performance, single-component (1K) polysiloxane topside coatings. These coatings are intended to be used on exterior applications where superior weathering resistance and durability are required. Substrates to which these coatings can be applied include wood, glass, metal, and structural plastics. Application can be by brush, roll, or spray, leaving no lingering odor and cleanup simply requires lacquer thinner. If applied in thin coats, ~ 2-4 mils, the surface will be dry and ready for additional coats within 30-45 minutes. Surfaces can be handled, including sanding, within 6-8 hours and will reach full hardness after 7 days. This new topside coating is chemical resistant to fuels, most solvents, and > 250 methyl ethyl ketone (MEK) double rub resistance after 24 hours.

De-Sensitization of Aluminum Alloys using Pulsed Electron Beams

The U.S. Naval Research Laboratory (NRL) has developed a new method of de-sensitizing sensitized 5XXX-series aluminum alloy plates on a single side without inducing bulk heating throughout the panel. This is accomplished by locally heating the near-surface volume to high enough temperatures (e.g., > 250 ºC) to dissolve the beta phase using pulsed electron beams. This reduces or eliminates grain boundary beta phase at the surface, where intergranular corrosion and stress-corrosion cracking occurs resulting in degraded service life of the alloy plate. This method allows for the controllable reduction in the degree of sensitization (DOS) by varying at least one of the following electron beam parameters: voltage, current density, pulse duration, pulse frequency, and total number of pulses. With an apparatus with a foil electron beam window, operation in ambient air would be possible; thus a portable eBeam system is within reason.

PEEK(TM)-like Phthalonitriles: Melt-Processable, High-Temperature Polymers

The Naval Research Laboratory (NRL) has developed a new class of PEEK™-like phthalonitrile (PN) resins for use in a variety of applications due to their ease of processability when in a melt-state followed by curing to produce high-temperature, high-char polymeric thermosets. The PN resins, where n < 1, were initially designed to fabricate polymer matrix composites (PMC) by cost effective manufacturing methods such as resin transfer molding, a type of out of autoclave (OOA) processing.

High Value Silicon Carbide from Agricultural Waste

Research scientists at the Naval Research Laboratory (NRL) have shown that using high temperatures or microwaves many agricultural wastes can be transformed into high value silicon carbide (SiC) consisting of nanostructures and nanorods in various polytypes. Billions of pounds of agricultural waste are generated every year world-wide. Rice and wheat husks, corn stalks, cobs, sorghum leaves, peanut shells and other residues are considered to have no value and are plowed into fields or incinerated.

Overlay of the two images (LSPR, transmitted light) with a map of secreted antibody concentrations as generated by Finite Element  Analyses. The colored concentration scale has units of pM and the distance scale bar is 10 μm Imaging Protein Secretions from Single Cells in Real Time

We have developed a label-free technique based upon nanoplasmonic imaging which enables the measurement of individual cell secretions with time resolutions below one second and spatial resolutions below 10 µm. This is accomplished by lithographically patterning gold plasmonic nanostructures into arrays atop standard glass coverslips. The nanostructures are functionalized for biomolecular detection using standard thiol chemistries and the detection of analyte binding is imaged by a CCD camera. As a result, the technique integrates seamlessly on to commercially available wide-field and confocal microscopes, allowing real-time transmitted light and fluorescence imaging of the cells, as well as the plasmonic imaging of secreted proteins. We anticipate this technique will be broadly applicable to the real-time characterization of both paracrine and autocrine signaling pathways with applications in immunology, developmental biology, wound healing and numerous diseases such as cancer.

Metrology Workbench: 3D Measurement and Visualization of Displacement and Strain Fields

NRL has developed a metrology workbench for the measurement and visualization of displacement and strain fields in three dimensions. The NRL workbench uses two or more cameras to image a specimen and includes custom software the implements the 3D Meshless Random Grid method. A random pattern of optically distinct dots is applied on the specimen surface. This procedure greatly reduces specimen preparation time compared to other optical methods.

Metallized Nanotextured Thin Films for Sensing and Catalyst Applications

NRL and Pennsylvania State University have developed a novel method for the metallization of nanotextured polymeric films that have sensing and catalyst applications. The method takes advantage of nanotextured polymer thin films, which are ideal metallization templates. The metallized nanotextured thin films have uses in biomedical implantation, metal–dielectric composites, energy storage, and biosensing platforms depending on the type of metal (i.e. gold, cobalt, nickel, etc.).

Nanofilm with Directional Wetting and Adhesion Properties

NRL and Pennsylvania State University have developed a nanofilm comprised of structured poly-(p-xylyene) (PPX) with directional wetting, adhesion, and droplet transport properties. The direction and extent of adhesion and wetability is adjusted through the formation of the PPX nanorods, which are fabricated with commercially available vapor deposition equipment. The result is a pattern of columns oriented at a non-perpendicular angle and a nanoscale surface roughness with unidirectional wetting properties.

Multi-Ply Heterogeneous Armor

NRL has developed impact armor with unparalleled performance for its weight. The armor consists of alternating layers of an elastic polymer and a harder material such as aluminum, ceramic, or an alternative polymer. Performance is enhanced with as few as six alternating layers. The layers can be attached to a thicker front plate or backing for additional protection. The armor affords protection against a range of threats, including armor piercing munitions and explosion fragments.

Transparent Spinel Ceramic

NRL has developed a suite of processes to create transparent spinel (MgAl2O4) ceramic, which is superior to the glass, sapphire, and other materials traditionally used for applications such as high-energy laser windows and lightweight armor. Commonly-used vacuum hot presses are utilized to sinter spinel powder into transparent solid materials. The NRL method includes a novel spray-coating process to uniformly coat the spinel powder particles with a sintering aid.

Nanowire-Based, Highly Efficient and Versatile Plasmonic Material for Enhanced Raman Spectroscopy

Raman spectroscopy is often used for chemical fingerprinting. However, the Raman process is very inefficient and difficult to use for trace detection. Rough metal surfaces (usually Ag or Au) are used to increase the Raman signal of trace levels of molecules adsorbed on these surfaces. This SERS enhancement of molecules on the roughened metal surface is caused by local electromagnetic fields that are created by the laser excitation of surface plasmons at the metal surface. Enhancements of up to 8 orders of magnitude have been observed. NRL investigators have completed significant work using dielectric core/metal nanowire composites and nanoshell and NW arrays.

Broad-Spectrum Biocide and Antiviral Coating

NRL has developed a series of biocides that, when formulated with the proper resin systems, produce coatings and polymers that kill a variety of bacteria, molds and viruses on contact. The advantages of the NRL biocide stems from the novel design of the molecule, with one end being hydrophobic and the other hydrophilic. This structure causes the biocide to preferentially migrate to the surface, where it is most effective, while the resin or coating is still liquid. The structure also greatly reduces removal by leaching once dried or cured.

Lase and Place

NRL has developed a laser-based device-transfer process for placing/embedding on any surface millimeter- to micrometer-size structures, such as semiconductor bare die, surface-mount and optoelectronic devices, sensors, actuators, and microelectro-mechanical systems (MEMS). The technique is less likely to cause damage to fragile components compared to the mechanical “pick and place” process and has been demonstrated capable of transferring 10-µm thick bare die, which is impossible to achieve with the current mechanical process.

New Processable Cyanate Ester Resins

Novel cyanate ester (CE) resins have been discovered with enhanced processability and increased toughness. The synthesis uses high-yield reactions to produce resins of various compositions and properties. Most notable is the formation of liquid CE resins while still maintaining high-thermal stability of the thermoset. The new CE resins have relatively low-curing temperatures and high-thermal stability, giving them a distinct advantage over other resin systems.

Inexpensive Synthesis of Carbon Nanotubes in Solid Domain

Our novel method of synthesizing carbon nanotube (CNT) and metal nanoparticle compositions involves melt processable organometallic compounds and polymers heat treated to elevated temperatures under atmospheric pressure. Formation of single-walled carbon nanotubes (SWNTs) and metal nanoparticles occurs at the atomic and molecular levels in the solid carbonaceous domain during the carbonization process.

Pulsed Laser Deposition of Ceramic Films

Thin film electronic ceramics will play a prominent role in the next generation of electronic devices. At NRL, this technique has been applied to a broad spectrum of ceramic systems to meet specific device application needs. Sophisticated analysis techniques are employed to characterize film phase, structure, morphology (X-ray diffraction, Rutherford backscattering, SEM, and TEM), and film-specific properties (resistance, polarization, magnetization, and optic).

Self-Decontaminating Filters, Clothing, and Disposable Wipes

NRL has developed a new self-decontaminating coating for use in filters, clothing, and disposable wipes that is capable of actively destroying pesticides, chemical agents, and certain bacteria on contact. The coating comprises a thin, layered, composite film containing enzymes, which actively degrade chemical toxins, and a polyelectrolyte binder. It is readily applied to substrates such as beads, fabrics, or paper by inexpensive methods such as dip coating, spin coating or spraying.

Rapid-Cure Coatings System

NRL has developed a durable, rapid cure coatings system that is designed for harsh environments. Developed for the maritime industry, it is suitable for the interior and exterior of shipboard structures and tanks as well as other applications where performance counts. The rapid cure of this coating system offers a near instant “walk-on time” and rapid return to service, typically within 30 to 45 minutes, with a single coat capability. This will greatly reduce the coatings application process time and cost during new construction and overhaul.

Laser Direct Writing Process for Microfabrication

The use of lithographic techniques for microfabrication of electronic and mechanical structures at the submillimeter level requires expensive facilities, extreme processing conditions, and timescales of the order of weeks to go from design to completed device. NRL has developed a novel laser-based direct-write approach for non-lithographic digital microfabrication of microelectronics and other devices that is simple, fast, economical and highly versatile.

PEEK(TM)-like Phthalonitriles: Base Resin Manufacturing

The Naval Research Laboratory (NRL) has developed a new class of PEEK™-like phthalonitrile (PN) resins, when in the melt-state, are easily processed and cured, and produce high-temperature thermosets. The PN base resins are synthesized in a two-step, one-pot reaction in quantitative yields and require no further purification (n

Nanoscale metal oxide coatings on 3D carbon nanoarchitectures. High Energy Storage Capacitor

The Naval Research Laboratory (NRL) has developed a method of electroless deposition of conformal ultrathin (<20 nm) metal oxides on the high-surface-area walls of commercial carbon nanofoam papers, typically 0.1–0.3 mm thick. The resulting ultrathin metal oxides rapidly take up and release electrons and ions, thereby storing energy at 300–600 Farads per gram of oxide, while the carbon nanofoam paper serves as a 3-dimensional current collector and defines a pre-selected porous electrode architecture.

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