|Updated: 11/24/2005; 11:38:05 PM.
Interesting tech developments in nanotech, nanostructured materials, etc.
Tuesday, February 18, 2003
Introduction to nanohorns
: "The types of nanotubes used for the experimental fuel cell are named nanohorns due to their irregular horn-like shape, and were discovered in the late 1990s. Although nanohorns have the same graphitic carbon atom structure as normal nanotubes, their distinguishing characteristic is a preference for grouping together to create an aggregate (that is, a secondary particle) of about 100nm. When used as an electrode for a fuel cell, not only is the surface area of the aggregate extremely large, but it is also easy for the fuel to permeate to the inside. Additionally, high purity nanohorns are easy to create (in comparison with other forms of nanotube) and are therefore predicted to be a low-cost raw material." In late 2001, JST and NEC "discovered that single layer nanohorn can storage 160 times methane in volume. By heat-treating single layer nanohorn at 400 °C under oxidizing atmosphere, nanohorn has nano-size fine pores and increases its surface area. In case of ordinary nanohorn, gas can flow through only conical opening, but in case of nanohorn having fine pores, gas can flow through also fine pores and methane gas is changed into super critical liquid by interference of methane molecule and nanohorn wall including fine pores even at room temperature. It is understood that these mechanism make nanohorn possible to storage methane in high density." NEC also reported efficient deposition of platinum
on nanohorns for use in fuel cells. 11:56:55 AM
Copyright 2005 © Ken Novak.
Last update: 11/24/2005; 11:38:05 PM.