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Lithium Fluoride as a Polysulfide Shuttle Inhibitor for Lithium Sulfur Chemistry

This invention imparts properties such as reinforcement, enhanced tensile strength, and/or electrical and thermal conductivity to composites. Lyndon B. Johnson Space Center, Houston, Texas In a lithium sulfur cell, the reduction of sulfur to lithium sulfide is a critical series of reactions that provides a large theoretical capacity of 1,672 mAh/g sulfur. One of many challenges in this system is the solubility of generated lithium polysulfides during the charge/discharge process. These polysulfides derived from the reduction of elemental sulfur are soluble in organic electrolytes, and can be reduced at the anode, causing an undesired reaction. Polysulfide species can also accumulate at the surface of the cathode and be further reduced to lower-order polysulfides such as Li2S2 or Li2S. The insulating nature of these lower-order polysulfides blocks the electron pathway on the carbon cathode.

Posted in: Briefs, TSP

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Fibers of Aligned Single-Wall Carbon Nanotubes and Process for Making the Same

This invention imparts properties such as reinforcement, enhanced tensile strength, and/or electrical and thermal conductivity to composites. Lyndon B. Johnson Space Center, Houston, Texas Single-wall carbon nanotubes (SWNTs) are fullerenes of closed-cage carbon molecules typically arranged in hexagons and pentagons. Commonly known as “buckytubes,” these cylindrical carbon structures have extraordinary properties, including high electrical and thermal conductivity, as well as high strength and stiffness. With intrinsic strength estimated to be on the order of 100 times that of steel, SWNTs are a possible strengthening reinforcement in composite materials. The intrinsic electronic properties of SWNTs also make them electrical conductors and useful in applications involving field mission devices such as flat-panel displays, and in polymers used for radio frequency interference and electromagnetic shielding that require electrical conductance properties.

Posted in: Briefs

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Enhancing MRI Contrast by Geometrical Confinement of Small Imaging Agents Within Nanoporous Particles

Lyndon B. Johnson Space Center, Houston, Texas Magnetic resonance imaging (MRI) has evolved into one of the most powerful, non-invasive diagnostic imaging techniques in medicine and biomedical research. The superior resolution and in-depth anatomical details provided by MRI are essential for early diagnosis of many diseases. Chemical contrast agents (CAs) have been widely used for improving the sensitivity and diagnostic confidence in MRI.

Posted in: Briefs

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Bonded Magnets: A Versatile Class of Permanent Magnets

Permanent magnets are ubiquitous in modern societies. Devices which use permanent magnets include motors, sensors, actuators, acoustic transducers, etc. These are used in home appliances, speakers, office automation equipment, aerospace, wind turbine generators, medical laboratory diagnostic test equipment, and more. It is estimated, for example, that a typical automobile uses up to 120 permanent magnets in windshield wipers, starter motors, seat adjusters, door lock actuators, fuel pumps, sensors, gauges, etc. The development of Hybrid Electric Vehicle and Electric Vehicle drive technologies has been greatly enhanced by the availability of high performance magnetic materials.

Posted in: White Papers, Coatings & Adhesives

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Case Studies with Poly(p-xylylene) Polymers – Parylene Coated Elastomers

In this Webinar we will focus most of our attention on parylene coating of elastomers. You will see commercially viable solutions that enhance lubricity and ruggedize elastomeric components operating in challenging environments.

Posted in: Webinars, On-Demand Webinars, Coatings & Adhesives

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Breaking Boundaries: Bioabsorbable Polymers in Device Design

It is well known that programming the performance of a bioabsorbable medical device is paramount to its success. But did you know that a large part of this programming takes place at the component level?

Posted in: Webinars, On-Demand Webinars

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Adhesion Reduction of Semiconductor Dicing Tape

Many semiconductor wafer processing techniques involve the fixing of a thin layer of dicing tape to a wafer during the final processing stages. To allow removal of the die from the tape, the adhesion properties of the tape may be reduced with exposure to high-intensity UV light.

Posted in: White Papers, Coatings & Adhesives

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