Journal Science – Carbon Nanotubes with Temperature-Invariant Viscoelasticity from –196° to 1000°C The material seems like it will be great for things like O-rings (a part that failed in the Space Shuttle).
Viscoelasticity describes the ability of a material to possess both elasticity and viscosity. Viscoelastic materials, such as rubbers, possess a limited operational temperature range (for example, for silicone rubber it is –55° to 300°C), above which the material breaks down and below which the material undergoes a glass transition and hardens. We created a viscoelastic material composed from a random network of long interconnected carbon nanotubes that exhibited an operational temperature range from –196° to 1000°C. The storage and loss moduli, frequency stability, reversible deformation level, and fatigue resistance were invariant from –140° to 600°C. We interpret that the thermal stability stems from energy dissipation through the zipping and unzipping of carbon nanotubes at contacts.
Nanotube arrangements leading to rubbery materials.
Images are from atomistic models of the displacement of entangled nanotubes relative to each other or temporary collapse (flattening) of thin tubes. (A) Three nanotubes (single-walled, double-walled, and triple-walled) are shown in contact with each other and interacting only by van der Waals forces. (B) The dumbbell shape of the collapsed nanotube decreases the distance between the walls to the interplanar spacing of graphite and temporarily creates van der Waals bonding in the middle area of the tube. (C) A hypothetical material consisting of interlocking nanotube rings that would be expected to display viscoelastic behavior.
var MarketGidDate = new Date();