Tuesday, September 11, 2007

US Patent 7267875 - Convertible nanostructure coating


This patent to Nanosys (filed June 7, 2005) presents a very broad patent claim to nanostructure coatings having an alterable property.

1. A discrete coated nanostructure comprising: an individual nanostructure coated with a first coating, wherein the first coating has a first optical, electrical, physical or structural property, and wherein the first coating is convertible to a second coating having a different optical, electrical, physical or structural property than the first coating.

The specification teaches core/shell nanoparticles in which multiple shell layers are used each with different properties. The outer shells may be removed to change the properties of the nanoparticles. However, the claims seem so broadly written that prior art using molecularly configurable coatings such as in electrochromatic films or rotaxanes/catenanes, which have adjustable electrical properties, may " read on" the claims. For example HP has used rotaxane films as coatings for nanowires which may be switched between resistance states in their nanowire crossbar arrays (see http://www.freepatentsonline.com/6128214.html)