Materials

Synthesis of Long-Chain-Branched (LCB) Polysulfones for Multifunctional Transport Membranes

Increasing numbers of technologies are based on the idea of harnessing charge transport for useful processes such as energy harvesting, actuation, and sensing. Although much progress exists based on perfluorosulfonated platforms, new and more complicated parameters arise as applications require multifunctionality in engineering materials. For instance, in addition to using lightweight, durable, stable, high-conductivity proton-exchange membranes in a fuel cell, it may be desirable to have the energy source bear load and operate as a structural installment. The most prevalent class of materials potentially capable of such a tradeoff is rubbery “salt-in-polymer” electrolytes that employ polymer segmental motion for transport of free ions from co-dissolved salts.

Posted in: Briefs, Materials, Fabrication, Conductivity, Elastomers, Electrolytes
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Biodegradable MEMS Based on Cellulose Paper

Electro-Active Paper(EAPap) has been recognized as a new smart material that can be used for sensors, actuators, biomimetic robots, and smart wallpapers. EAPap is made with cellulose paper by coating thin electrodes on both sides of it. This paper can produce a bending or longitudinal strain in the presence of an electric field. Also, it can produce an induced charge under the external stress. This EAPap material has many advantages in terms of large displacement output, low actuation voltage, low power consumption, dryness, flexibility, sensing capability, and biodegradable characteristics.

Posted in: Briefs, Materials, Microelectricmechanical device, Sensors and actuators, Fabrication, Lightweight materials, Materials properties, Smart materials
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Functionalized Silk Materials

T he goal of this work was to exploit the novel structural, physical, and biological features of silk proteins towards functionalization of materials systems generated from this family of protein. A new generation of functional silk systems is sought to provide novel materials with precise control of material features. Three main directions were planned: (a) protein chimeras to form organic (silk) – inorganic nanocomposites; (b) formation of electronic materials using a similar design strategy, but based on enzymatic coupling reactions to form conducting polymers; and (c) continuing to understand and exploit novel processing approaches with these proteins towards new functional materials systems.

Posted in: Briefs, Materials, Research and development, Fabrication, Biomaterials, Materials properties
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Dynamic Response and Failure Mechanisms of Layered Ceramic-Elastomer-Polymer/Metal Composites

A thorough study through a combination of ballistic and impact experiments, microscopic failure characterization, and numerical simulations has been carried out in order to decipher the underlying mechanisms involved in the interaction between a blast and/or a blast-induced high-velocity projectile and advanced ceramic-polymer and metal-polymer composites, resulting in an improved ballistic efficiency and impact- and blast-resistant structural system.

Posted in: Briefs, Materials, Ceramics, Composite materials, Elastomers, Metals, Protective equipment, Military vehicles and equipment
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Fire Resistance of Geopolymer Concretes

Geopolymer concrete has been proposed as an alternative to Portland cement concrete in applications requiring high degrees of fire resistance, because the intrinsic chemistry of the geopolymer binder does not require the retention of water or hydration within gel phases to maintain structural integrity of the binder. Portland cement concrete contains a high level of chemically bound water, which is essential to the gel binder structure, and which is lost upon heating to several hundred degrees Celsius, whereas the water present within a geopolymer concrete is overwhelmingly present in pores and is not an essential part of the strength-generating phases. However, predictions of geopolymer concrete fire performance have up to this time been based on small-scale laboratory testing (usually on paste or mortar specimens), rather than the study of large concrete sections, which provides significance to this work.

Posted in: Briefs, Materials, Composite materials, Heat resistant materials, Polymers, Fire
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Tomographic Electrical Resistance-Based Damage Sensing in Nano-Engineered Composite Structures

Advanced composite materials are increasingly replacing metals in the aerospace industry as they offer weight-saving improvements such as high specific strength and stiffness, while providing resistance to fatigue and corrosion. Traditional advanced composites, however, exhibit significantly reduced electrical and thermal conductivity relative to metals, and matrix-rich regions at ply interfaces result in relatively poor interlaminar properties. Additionally, composites that have sustained damage often have non-visible or barely visible damage, complicating damage assessment. Recent efforts to address the limitations of advanced composites include the incorporation of carbon nanotubes (CNTs) to take advantage of intrinsic and scale-dependent properties of these nanostructures.

Posted in: Briefs, Materials, Aircraft structures, Composite materials, Conductivity, Nanomaterials
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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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