Melting gold normally requires temperatures upwards of 1,064° C (1,947° F), but in a scientifically groundbreaking discovery, a way was found to melt gold at room temperature. According to a news story, atoms of a gold cone, when exposed to a strong electric field, break almost all their connections to each other and the surface layers begin to melt. This was noticed to occur when gold was viewed under an electron microscope.
What happened was that the gold atoms became excited. Under the influence of the electric field, they suddenly lost their ordered structure and released almost all their connections to each other. Upon further experimentation, the researchers discovered that it was also possible to switch between a solid and a molten structure.
The discovery of how gold atoms can lose their structure in this way is not just spectacular, but also groundbreaking scientifically. Together with the theoretician Mikael Juhani Kuisma, from the University of Jyväskylä in Finland, Ludvig de Knoop and colleagues have opened up new avenues in materials science. The results are now published in the journal Physical Review Materials.
Thanks to theoretical calculations, the researchers are able to suggest why gold can melt at room temperature. Possibly, the surface melting can be seen as a so-called low-dimensional phase transition. In that case, the discovery is connected to the research field of topology, where pioneers David Thouless, Duncan Haldane and Michael Kosterlitz received the Nobel Prize in Physics 2016. With Mikael Juhani Kuisma in the lead, the researchers are now looking into that possibility.
In any case, the ability to melt surface layers of gold in this manner enables various novel practical applications in the future.
“Because we can control and change the properties of the surface atom layers, it opens doors for different kinds of applications. For example, the technology could be used in different types of sensors, catalysts and transistors. There could also be opportunities for new concepts for contactless components,” says Eva Olsson, Professor at the Department of Physics at Chalmers.
The change was also reversible, as switching off the electric field can solidify the gold again.
I don’t get it. Wasn’t gold electroplating discovered like 213 years ago? Why this is not just simple gold electrolysis?
Italian chemist, Luigi Brugnatelli invented electroplating in 1805. Brugnatelli performed electrodeposition of gold using the Voltaic Pile, discovered by his college Allessandro Volta in 1800.
Electroplating is the process of coating one metal or metal object with a very thin layer of another metal, typically by applying a direct electric current. This partially dissolves the metals and creates a chemical bond between them. The coating applied by electroplating is usually around 0.0002 inches thick.
Gold is a noble metal, meaning it is resistant to corrosion and oxidation in most environments. It is the most non-reactive of all metals. Gold never reacts with oxygen, making this material resistant to rust or tarnishing. … Gold is also an excellent conductor of electricity.
The bond-dissociation energy (BDE, D° or DH°) is one measure of the strength of a chemical bond A–B
The terms “bond enthalpy“, “bond strength” and “bond energy” are interchangeable.
One gold atom (atomic number 79 – (has 79 protons)) alone is (Au+) a postive ion, but gold ions, like other metals, naturally join to form metalic bonds. They join because they are electron deficient and they therefore share electrons.
Metal atoms contain few electrons in their valence shells relative to their periods or energy levels. They are electron deficient elements and the communal sharing does not change that. There remain far more available energy states than there are shared electrons.
The strength of the bond between atoms of elemental gold (chemical symbol Au) has been measured since 1956. At 0 degrees K, it takes 159 ±8 kj/mol or 38 ±2 kcal/mol of energy to break gold molecule bonds. (1970 table of bind energies), but, bond dissociation energy measurements are challenging and have been subject to considerable error. Most currently known values are accurate to within ± 1 or 2 kcal/mol.
One “mol” of gold atoms is by the 2019 definition of a mol 602.214076 sextillion gold atoms. (A mol is a constant and like a dozen, it is always the same number. A mol of you would be 602.214076 sextillion of you.)
In science, 300 K can also be used as room temperature for easy calculations when using absolute temperature. Other common values are 298 K (25°C or 77 °F) and 293 K (20°C or 68 °F).
Temperature is a measure of how fast atoms are moving around (or vibrating in a matrix). The faster the atoms move, the hotter the material liquid, or gas, and the more easily separated. When gold melts at the high temperature of 1,947° F, the atoms of gold are moving so much that they are no longer held in a solid matrix by the shared electrons between gold atoms.
Gold atoms stick together due to sharing electrons. Electicity is a flow of electrons and if you pass more electrons by a gold atom than it has from other gold atoms around it, the gold atom, despite vibrating at only room temperature, will follow the flow of electrons because each atom of gold needs more electrons than it gets from sharing electrons with its own kind. Can you understand the pyramid shape used in this experiment now?
Gold molecules at the tip of the pyramid will have fewer other gold molecules around them to hold them together, so they will break off and follow the electrons outside of the metal when external electrons are able to overcome the power of the metalic bonds ( sharing electrons ) with other gold molecules.
Is there more to this discovery that I’m missing?
Why are they calling this is new scientific breakthrough? Check back here (TrueStrange.com) and I’ll update this post if I ever figure it out.
If you are a materials scientist, leave a comment and enlighten us!