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
  • bet23
    bet23Tuesday, March 3, 2020 at 12:37 pm
    sick bro
    • alicorn2222
      alicorn2222Tuesday, March 3, 2020 at 7:56 am
      this is soooooo cool
      • ronaasefa
        ronaasefaMonday, March 2, 2020 at 11:22 am
        i can make that easy
        • gachaboy2020
          gachaboy2020Monday, March 2, 2020 at 7:51 am
          its not that bad
          • gachaboy2020
            gachaboy2020Monday, March 2, 2020 at 7:40 am
            this was so cool
            • tinydancer1122
              tinydancer1122Sunday, March 1, 2020 at 6:38 pm
              I thank the engineers who made the light weight gold! Now if I have to wear gold to any of my dance competitions it will be light weight! Woot woot! I bet you 100 bucks that salesman selling gold will have a lot more success!
              • sciencenews
                sciencenewsFriday, February 28, 2020 at 1:33 pm
                soooooo cooooool
                • foxygurl123
                  foxygurl123Friday, February 28, 2020 at 8:53 am
                  Thats cool but is it the same value as real gold????
                  • itzbugzooo
                    itzbugzoooThursday, March 5, 2020 at 1:37 pm
                    Sadly, no. This is very similar to crushing coal under heat into artificial diamonds. The process is not very expensive, but because it was not found naturally (from the earths crust, or from rare meteors), it is considered not as valuable. A while back scientist were taking lead (Pb, 82 on the Periodic scale) and knocking off a few protons. The were able to successful able to make in into gold, but because it was not found naturally, it is worth much less. Sorry, but no you wont go rich from turning plastic to gold.
                    • hmm_no
                      hmm_noTuesday, March 10, 2020 at 7:33 am
                      welp shes right i checked google for like 10 minutes seeing if she or he copyed it from google and other search engines bravo
                      • cloudstar_360
                        cloudstar_360Thursday, March 5, 2020 at 5:28 pm
                        WOW. You are really smart, I didn't even know that! 🤓
                      • dorischou
                        dorischouTuesday, March 3, 2020 at 6:19 am
                        I... think so.
                      • amatuer
                        amatuerFriday, February 28, 2020 at 7:33 am
                        so cool
                        • lightfury
                          lightfuryThursday, February 27, 2020 at 12:10 pm
                          also Im in 4TH grade! larsen elementary