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A New Lightweight Gold Made with Plastic Developed

All that glitters (might be) gold.

A new, lightweight gold made with plastic has been developed. This concoction has all the sheen and glitter you expect in gold, only far lighter. Here’s what we know about plastic gold so far.

The Inspiration

Researchers at ETH lab set out to create a new form of gold that weighed five to 10 times less than traditional 18-karat gold. Prior to creating plastic gold, the team had already made a name for themselves by developing the lightest gold in the world— gold that was so light it could float on cappuccino froth. Their latest creation marks yet another advancement in the manufacturing of gold.

The Scoop on Traditional Gold

Gold in its purest state is not practical for jewelry. Crafting gold jewelry for everyday wear requires mixing it with a stronger metal to make it lighter and more resistant to damage. However, alloying gold with another metal reduces its purity. For example, 24-karat gold is commonly blended with copper resulting in a lower purity karat such as 18-karat. Fortunately, the team at ETH knew it could replace the metal with plastic to make it even lighter while retaining the same level of purity.

How Plastic Gold Was Created

ETH developed plastic gold by mixing, namely, plastic in place of metals. What resulted was a new, lightweight gold with a much lighter density than traditional gold.

The process of creating plastic gold follows four steps:

  1. Tiny gold platelets, polymer latex, protein fibers, water and salt are combined to create a gel.
  2. After the gel is formed, the water inside is replaced by alcohol. The new alcoholic gel is placed into a pressure chamber where the supercritical CO2 atmosphere allows the alcohol and CO2 to mix the properties of the gel.
  3. The pressure in the chamber is released, and the substance turns into a homogenous aerogel.
  4. Heat is applied to the aerogel to toughen its plastic polymers, resulting in an 18 carat plastic gold piece.

“This gold has the material properties of a plastic,” researcher Raffaele Mezzenga said. “If a piece of it falls onto a hard surface, it sounds like plastic. But it glimmers like metallic gold, and can be polished and worked into the desired form.”

Why Use Plastic Gold?

Traditional gold watches and jewelry are heavy. Using a lightweight, plastic gold allows people to wear their favorite accessories comfortably without losing any luster.

There are many unusual uses for gold. Plastic gold applications include:

  • Chemical catalysis
  • Electronics applications
  • Radiation shielding

Plastic gold allows for much lighter, comfortable jewelry and can also be used functionally in certain applications. What remains to be seen is whether people will accept the costume jewelry feel of plastic gold as opposed to the heavier consistency of traditional gold.

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