Materials

Polymer-Reinforced, Non-Brittle, Lightweight Cryogenic Insulation

The primary application for cryogenic insulating foams will be fuel tank applications for fueling systems. It is crucial for this insulation to be incorporated into systems that survive vacuum and terrestrial environments. It is hypothesized that by forming an open-cell silica-reinforced polymer structure, the foam structures will exhibit the necessary strength to maintain shape. This will, in turn, maintain the insulating capabilities of the foam insulation. Besides mechanical stability in the form of crush resistance, it is important for these insulating materials to exhibit water penetration resistance. Hydrocarbon-terminated foam surfaces were implemented to impart hydrophobic functionality that apparently limits moisture penetration through the foam. During the freezing process, water accumulates on the surfaces of the foams. However, when hydrocarbon-terminated surfaces are present, water apparently beads and forms crystals, leading to less apparent accumulation.

Posted in: Materials, Briefs

Read More >>

Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value

This aerogel insulation could be used in fuel cell systems, oil and gas pipelines, and in building and construction applications. A sprayable aerogel insulation has been developed that has good mechanical integrity and lower thermal conductivity than incumbent polyurethane spray-on foam insulation, at similar or lower areal densities, to prevent insulation cracking and debonding in an effort to eliminate the generation of inflight debris.

Posted in: Materials, Briefs

Read More >>

Controlled, Site-Specific Functionalization of Carbon Nanotubes With Diazonium Salts

Possible applications include molecular switches and molecular wires. This work uses existing technologies to prepare a crossbar architecture of nanotubes, wherein one nanotube is fixed to a substrate, and a second nanotube is suspended a finite distance above. Both nanotubes can be individually addressed electrically. Application of opposite potentials to the two tubes causes the top tube to deform and to essentially come into contact with the lower tube. Contact here refers not to actual, physical contact, but rather within an infinitesimally small distance referred to as van der Walls contact, in which the entities may influence each other on a molecular and electronic scale.

Posted in: Materials, Briefs

Read More >>

A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries

A document discusses a thin layer of composite material, made from nano scale particles of nickel and Teflon, placed within a battery cell as a layer within the anode and/or the cathode. There it conducts electrons at room temperature, then switches to an insulator at an elevated temperature to prevent thermal runaway caused by internal short circuits. The material layer controls excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect.

Posted in: Materials, Briefs, TSP

Read More >>

Non-Toxic, Non-Flammable, –80 ºC Phase Change Materials

The objective of this effort was to develop a non-toxic, non-flammable, –80 °C phase change material (PCM) to be used in NASA’s ICEPAC capsules for biological sample preservation in flight to and from Earth orbit. A temperature of about –68 °C or lower is a critical temperature for maintaining stable cell, tissue, and cell fragment storage.

Posted in: Materials, Briefs, TSP

Read More >>

Soft-Bake Purification of SWCNTs Produced by Pulsed Laser Vaporization

A more efficient, cost-effective, environmentally friendly method purifies high-quality carbon nanotubes. The “soft-bake” method is a simple and reliable initial purification step first proposed by researchers at Rice University for single-walled carbon nanotubes (SWCNT) produced by high-pressure carbon mon - oxide disproportionation (HiPco). Softbaking consists of annealing as-produced (raw) SWCNT, at low temperatures in humid air, in order to degrade the heavy graphitic shells that surround metal particle impurities. Once these shells are cracked open by the expansion and slow oxidation of the metal particles, the metal impurities can be digested through treatment with hydrochloric acid.

Posted in: Materials, Briefs, TSP

Read More >>

Improved Wide Operating Temperature Range of Li-Ion Cells

Applications include electric vehicles, where high-energy-density and high-power batteries are needed that can operate at low temperature. Future NASA missions aimed at exploring the Moon, Mars, and the outer planets require rechargeable batteries that can operate over a wide temperature range (–60 to +60 ºC) to satisfy the requirements of various applications including landers, rovers, penetrators, CEV, CLV, etc. This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range.

Posted in: Materials, Briefs, TSP

Read More >>

White Papers

When Wire Feedthroughs Make Sense
Sponsored by Douglas Electrical Components
Uncooled Infrared Imaging: Higher Performance, Lower Costs
Sponsored by Sofradir EC
3D Printing in Space: The Next Frontier
Sponsored by Stratasys
Piezo Engineering Tutorial
Sponsored by aerotech
Software Defined Radio Handbook
Sponsored by Pentek
Manager's Guide to Productivity Gains with Multiphysics Simulation Part II: Speed Innovation & Reduc
Sponsored by COMSOL

White Papers Sponsored By: