Scientists Use Plastic To Create Lightweight 18-Carat Gold

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The new plastic gold closely resembles its metallic gold but it's much lighter (Credit: ETH Zurich/Peter Rüegg)

While jewelry crafted from gold can be gorgeous, even ardent fans will admit that wearing the heavy metal over long periods of time can get a little cumbersome and annoying. Now, researchers from Swiss university ETH Zurich have created a new form of lightweight gold that weighs five to ten times less than traditional 18-carat gold — which typically comprises 75 percent gold and 25 percent copper — but retains the same purity.

The researchers began by mixing gold nanocrystals with protein fibers, polymer latex, water, and salt to create a gel. They then replaced the water with alcohol and placed the gel inside a high-pressure carbon dioxide (CO2) chamber. The reaction between the gas and alcohol transformed the golden plastic into a light aerogel that could be heated to melt and mold into whatever form was needed. "This gold has the material properties of a plastic," says team leader Raffaele Mezzenga, professor of Food and Soft Materials at ETH Zurich.

A microscope image of gold nanoplatelets embedded in a latex matrix (Credit: Stephan Handschin/ScopeM/ETH Zurich)

In addition to being lighter, the "plastic" gold has other advantages over traditional forms. It can be melted into shape at about 105 degrees Celsius (221 degrees Fahrenheit), much lower than the 1,064 degrees Celsius (1,947 degrees Fahrenheit) required to melt pure 24-carat gold. The metal's firmness can be easily tweaked by changing the composition at the beginning of the process. It is also possible to vary the color by swapping the shape of the gold nanoparticles inside the matrix. For example, irregularly-shaped nanoplatelets will produce the conventional yellow shimmer, while spherical nanoparticles will result in gold with a violet hue. "As a general rule, our approach lets us create almost any kind of gold we choose, in line with the desired properties," says Mezzenga.

The researchers, who published their study in the journal Advanced Functional Materials on January 10, 2020, believe the new lightweight gold will be able to replace the metallic version in most traditional applications, including jewelry and watches. However, given that most buyers associate high-quality gold with weight, that may take some time. But the gleaming material will undoubtedly be beneficial for use inside electronic devices, chemical catalysts, and even radiation shielding.

Resources: newsatlas.com, phys.org, cnet.com

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150 Comments
  • gamerkidjoe
    gamerkidjoeMonday, March 16, 2020 at 5:39 am
    I wonder how long it takes to make the gold
    • bobypandas123
      bobypandas123Thursday, March 12, 2020 at 7:24 am
      "it is so cool"
      • loveroflegos
        loveroflegosTuesday, March 10, 2020 at 3:09 pm
        so we can all be rich right
        • texasrocks88
          texasrocks88Sunday, March 22, 2020 at 4:21 pm
          no we cant
          • rand
            randWednesday, March 11, 2020 at 12:55 pm
            it would actually be less value
            • apex_games297
              apex_games297Sunday, April 19, 2020 at 6:25 am
              Yes and no because gold's price is measured by it's weight, but gold is very rare.
          • griindz
            griindzTuesday, March 10, 2020 at 10:25 am
            to all the people who say just make a huge profit, just no, just, no, please god no, NO
            • skeletron707
              skeletron707Tuesday, March 10, 2020 at 7:27 am
              cool i what to make gold like that
              • melzippydog
                melzippydogFriday, March 6, 2020 at 8:32 pm
                It sounds a bit tricky
                • cloudstar_360
                  cloudstar_360Thursday, March 5, 2020 at 5:26 pm
                  I want to try and make my own gold, now. ;)
                  • gachaboy2020
                    gachaboy2020Thursday, March 5, 2020 at 7:27 am
                    its easy to make all you need is plastic and a special type of gel
                    • jmanepic
                      jmanepicWednesday, March 4, 2020 at 7:53 am
                      this is cool
                      • bet23
                        bet23Tuesday, March 3, 2020 at 12:37 pm
                        sick bro