Materials

Polymer Coating Material Limits Computer Damage Caused by Vibrations

Cornerstone Research Group (Dayton, OH) has developed an organic, polymer-based material that can be directly applied to any circuit board — as well as other metal- and plastic-based objects — to protect against vibrations.

Posted in: Tech Transfer Reports, Coatings & Adhesives
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Real-Time Intelligent Chemical and Biological Nanosensors on a Flexible Platform

The objectives of this research are to examine the feasibility of real-time sensing of chemical and biological species by using the unique materials and electronic properties of carbon nanotubes, and to demonstrate the multi-agent sensing and information processing capabilities of such devices.

Posted in: Briefs, Materials, Sensors and actuators, Biomaterials, Chemicals, Nanotechnology
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Templated Synthesis of Aluminum Nanoparticles for Stable Energetic Materials

Reactive nanoparticles as energetic materials have received much recent attention for a variety of existing and/or potential applications. Among more extensively investigated are nanosized (sub-100-nm) aluminum (Al) particles. Their large specific surface area and energy density, when coupled or mixed with oxidative species, make them unique combustible additives in propellant formulations. Nanoscale Al particles are also studied as high-capacity hydrogen storage materials. Therefore, significant effort has been made in the development of synthetic methodologies for Al nanoparticles of desired properties.

Posted in: Briefs, Materials, Hydrogen storage, Propellants, Fabrication, Aluminum, Nanomaterials
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Performance Evaluation of Commercial Carbon Monofluoride Materials in Lithium Batteries

The performance of six different commercially available carbon monofluoride (CFx) materials was evaluated at four different discharge rates. The physical and chemical properties of the CFx materials were correlated to cell performance in lithium coin cells. This study was undertaken to determine how the physical and chemical properties of commercial CFx materials affect discharge capacity, discharge voltage, rate capability, and voltage delay in Li-CFx cells.

Posted in: Briefs, Materials, Lithium-ion batteries, Performance tests, Test procedures
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Nanodomain Model of Polymer-Derived Ceramics

Areport discusses a model developed to explain the unusual properties of polymer- derived ceramics (PDCs), which are so named because they are made by controlled pyrolysis of cross-linked polymers. PDCs are metastable ceramics that have potential to be further developed into high-temperature materials that can be tailored to have properties needed to perform specific functions. The PDCs studied thus far have comprised silicon, carbon, nitrogen, and oxygen. The unusual properties of PDCs are the following: They bear similarity to both polymers and metallic glasses, even though the pyrolysis temperatures used in producing them are with experimental data.

Posted in: Briefs, Materials, Simulation and modeling, Ceramics, Heat resistant materials, Materials properties, Polymers
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Characterization of High-Temperature Polymer Thin Films for Power Conditioning Capacitors

Wide bandgap semiconductors (e.g., silicon carbide) will enable operation of military systems at temperatures above 150 °C, which eases thermal management. However, such systems cannot be designed efficiently unless capacitors are available that can operate at similarly high temperatures.

Posted in: Briefs, Materials, Capacitors, Heat resistant materials, Polymers, Semiconductors, Military vehicles and equipment
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RF Polymer Composites for Electromagnetic Systems

Design of polymer composites with specific engineered electromagnetic properties are of use in a variety of physical electromagnetic systems above 100 MHz. In physical electromagnetic systems such as GPS, radomes, WiFi, etc., proper choice of the material can be transformative in that it can yield considerably better performance. Of interest in this work is the possible development of low-loss magneto-dielectric composites. This project investigates various aspects of material systems, starting with possible composite designs, to design of measurement techniques, to development of finite element models for complex waveguide and conformal antenna configurations that use these materials.

Posted in: Briefs, Materials, Finite element analysis, Antennas, Waveguides, Composite materials, Materials identification, Polymers
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Modeling Defects in Transparent Ceramics to Improve Military Armor

The dominant materials solution used for ballistic transparency protection of armored tactical platforms in commercial and military applications is low-cost glass backed by polycarbonate. Development of next-generation ceramics is critical to offering enhanced protection capability and extended service performance for future armored windows to the soldier. Among the potential ceramic materials considered for armor — sapphire, edge-form-growth sapphire, magnesium aluminate spinel, aluminium oxynitride — one was selected for the current pursuit: magnesium aluminate spinel (MgAl2O4).

Posted in: Briefs, Materials, Windows and windshields, Failure modes and effects analysis, Ceramics, Occupant protection, Military vehicles and equipment
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Validation of Hazardous Air Pollutant (HAP)-Free Torque Seal Inspection Lacquer

The Army uses numerous adhesives and sealants, among other coating materials, that contain significant amounts of hazardous air pollutants (HAPs). This work examines laboratory and field demonstration/validation of one sealant, Torque Seal. A HAP-free alternative to Torque Seal containing ethanol as the carrier solvent has been identified. Laboratory testing including adhesion, resistance to fluids, resistance to humidity, and drying time validated that the HAP-free sealant performs very similarly to the baseline Torque Seal containing methanol (HAP). Furthermore, a demonstration study at Fort Rucker, AL, using a UH-1 helicopter rotor, shows that the HAP-free sealant performed as well as the Torque Seal.

Posted in: Briefs, Materials, Air pollution, Adhesives and sealants, Performance tests, Test procedures, Military aircraft, Military vehicles and equipment
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Multifunctional Properties of Structural Gel Electrolytes

Due to the demand for more advanced and lightweight systems, multifunctional composite structures that can function as electrochemical energy converters, while bearing mechanical load, are in development. This research involves a materials-based approach in which each component of the system serves to bear and/or efficiently transfer load. In this iteration, multifunctional structural gel electrolytes were prepared by the integration of conductive pathways using non-aqueous solvents into structural resin networks. Polyethylene glycol (200 MW) and propylene carbonate were used as the non-aqueous solvents, while vinyl ester and epoxy resin were used as structural resins. The monomer and solvents were incorporated together and polymerized to create conductive pathways in cross-linked networks. The impact of chemistry and weight fraction of both liquid and resin were investigated on the electrochemical-mechanical response of the resulting system.

Posted in: Briefs, Materials, Aircraft structures, Body structures, Composite materials, Electrolytes, Materials properties
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