Gold Nanoparticles Go Couture

Marino wool is about to go high-fashion.

By adding nanoparticles made of pure gold and silver to fine Marino 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.

"Silver nanoparticles are a bit trickier," said Johnston.

Sizes and shapes determine the color of silver nanoparticles, which can be spheres, triangles, round plates or even prisms. They can be shades of green, yellow or orange.

Besides the cachet that comes with clothing yourself in precious metal, Johnston also claims that the process is environmentally friendly, an advantage over traditional dyes.

The wool is also fade-free, handles abrasion well and eliminates static electricity, said Johnston. The gold nanoparticles never wash out.

Besides, "it's very soft and has a nice appearance with a subtle color," he added.

Precious-metal nanoparticles are not new. Gold nanoparticles have been used unwittingly for centuries in red stained-glass windows and are being explored for their potential medical benefits.

Over the last decade, silver nanoparticles have been added to everything from socks to teddy bears for their antibacterial properties, despite recent findings that suggest their leakage into water systems.

Precious-metal-dyed wool isn't for the everyday buyer, and a gold- or silver-dyed wool sweater will be at least several times more expensive than the average wool sweater. Johnston estimates that a scarf made of the wool, which was displayed at the conference "hot off the loom," will cost between $200 and $300.

"It's the difference between a BMW and a Toyota," said Johnston.

While Johnston won't mention which specific fashion designers he is in talks with, he hopes that the first precious metal dyed garments will appear in a year or so.

"This is very interesting research," said Kevin Conley, a nanotechnology researcher at Forsyth Technical Community College who attended Johnston's presentation but was not involved in the work.

"I think this will put a smile on people's faces and help advance nanotechnology," said Conley.

Special Thanks to Discovery