A new form real gold, almost as light as air

A new form of real gold, almost as light as air

9:25 AM, 27th November 2015
A new form of real gold, almost as light as air
The 20 carats gold foam is lighter than milk foam, so light that it does not sink.

ZURICH, SWITZERLAND: Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible to tell the difference with the naked eye. There are many possible applications.

A nugget of real 20 carats gold, so light that it does not sink in a cappuccino, floating instead on the milk foam – what sounds unbelievable has actually been accomplished by researchers from ETH Zurich.

Scientists led by Raffaele Mezzenga, prof of food and soft materials, have produced a new kind of foam out of gold, a three-dimensional mesh of gold that consists mostly of pores. It is the lightest gold nugget ever created.

“The so-called aerogel is a thousand times lighter than conventional gold alloys. It is lighter than water and almost as light as air,” said Mezzenga.

The new gold form can hardly be differentiated from conventional gold with the naked eye – the aerogel even has a metallic shine. But in contrast to its conventional form, it is soft and malleable by hand. It consists of 98 parts air and only two parts of solid material. Of this solid material, more than four-fifths are gold and less than one-fifth is milk protein fibrils. This corresponds to around 20 carat gold.

The scientists created the porous material by first heating milk proteins to produce nanometre-fine protein fibres, so-called amyloid fibrils, which they then placed in a solution of gold salt. The protein fibres interlaced themselves into a basic structure along which the gold simultaneously crystallised into small particles. This resulted in a gel-like gold fibre network.

This study is published in the journal Advanced Materials.

The method chosen, in which the gold particles are crystallised directly during manufacture of the aerogel protein structure, is new. The method’s biggest advantage is that it makes it easy to obtain a homogeneous gold aerogel, perfectly mimicking gold alloys.

“The optical properties of gold depend strongly on the size and shape of the gold particles,” said Gustav Nystrom, postdoc in Mezzenga’s group and first author of the study. “Therefore we can even change the colour of the material in order that the gold doesn't crystallise into microparticles but rather smaller nanoparticles, it results in a dark-red gold.”

The new material could be used in many of the applications where gold is currently being used, said Mezzenga. The substance's properties, including its lighter weight, smaller material requirement and porous structure, have their advantages.

The material could also be used in applications where light is absorbed or reflected. Finally, the scientists have also shown how it becomes possible to manufacture pressure sensors with it.

“At normal atmospheric pressure the individual gold particles in the material do not touch, and the gold aerogel does not conduct electricity,” explained Mezzenga. “But when the pressure is increased, the material gets compressed and the particles begin to touch, making the material conductive.”

© ETH Zurich News

0 Comments

Login

Your Comments (Up to 2000 characters)
Please respect our community and the integrity of its participants. WOC reserves the right to moderate and approve your comment.

Related News


New ‘self-healing’ gel makes electronics more flexible

AUSTIN, US: Researchers in the Cockrell School of Engineering at The University of Texas at Austin have developed a first-of-its-kind self-healing gel ...

Read more
Chemical design made easier

HOUSTON, US: Rice University scientists using an efficient metal-free process have synthesized dozens of small-molecule catalysts, tools that promise ...

Read more
Atom-sized craters make a catalyst much more active

MENLO PARK, US: Bombarding and stretching an important industrial catalyst opens up tiny holes on its surface where atoms can attach and react, greatl ...

Read more
Paras to use Novozymes’ osteoporosis treatment technology Veltis

OULU, FINLAND: Paras Biopharmaceuticals Finland Oy said that it has collaborated with Novozymes A/S to use the latter’s Veltis technology to dev ...

Read more
DSM to boost Akulon XS capacity for flexible packaging films

HEERLEN, NETHERLANDS: Royal DSM said it is expanding production capacity for Akulon XS at its facility in Emmen, Netherlands. The capacity increase is ...

Read more
Tap water, salt in cooking may make food toxic: Study

BEIJING, CHINA: Cooking with chloraminated tap water and iodised table salt could put potentially harmful toxins in your food, a new study has warned. ...

Read more
www.worldofchemicals.com uses cookies to ensure that we give you the best experience on our website. By using this site, you agree to our Privacy Policy and our Terms of Use. X