Gold Nanoparticles Go Couture

June 13, 2008 -- Merino wool is about to go high-fashion.

By adding nanoparticles made of pure gold and silver to fine Merino wool, researchers in New Zealand have created a rainbow of unexpected colors intended for high-end, couture fashion designers.

They unveiled the first scarf dyed with gold nanoparticles last week at the Nano Science and Technology Institute convention in Boston.

"We want to create a fashion icon, like Louis Vutton or Gucci, where the logo will speak for itself," said James Johnston, the lead researcher from Victoria University in New Zealand.

"You could say that you are clothed in pure gold or silver," said Johnston.

The dyed wool is not gold or silver in color, however. When dyed with gold nanoparticles, wool, or just about any other fabric for that matter, ranges from purple to yellow and everything in between.

Silver nanoparticles create bright yellows, greens and oranges.

The researchers can even combine and mix colors to create new ones. Varying the amount of gold or silver nanoparticles determines the shade's intensity.

The color of the wool depends on the type of precious metal used, the size of the nanoparticles, and in some cases, their shape.

Spherical gold nanoparticles about 10 nanometers across create a red wine color. As their size increases to 100 nanometers, the color turns red, then purple, blue, and finishes off in various shades of gray.