For the first time ever, an international team of physicists from Switzerland, Finland, Japan, Germany, and Sweden successfully measured the very weak and tiny forces between atoms — a force known as van der Waals' interactions.
If you remember from high school chemistry, then you might recall that the van der Waals force is just the weak bond between molecules, triggered by the way electrons move at the atomic level.
The van der Waals force is the result of unstable electric fields around atoms and molecules, which can generate small repulsive or attractive forces. It is considered weaker than chemical bonds such as covalent and ionic bonds.
However, these weaker forces prove to be surprisingly useful when it comes to adhesion, cohesion, friction, and condensation.
Geckos that climb walls take advantage of the van der Waals force. Strapless bras also provide efficient support because of it.
Measuring The Van Der Waals Force
To measure the van der Waals force, scientists from the University of Basel and the Swiss Nanoscience Institute embedded different atoms into a copper molecular grid. The embedded atoms include noble gases such as xenon, argon, and krypton.
Researchers refer to the void between these copper lattices as the "nano-beakers" of atoms where the noble gas atoms are held in place like an egg.
The Basel research team measured the tiny fluctuating forces between atoms through the use of an atomic force microscope. These noble gas atoms were placed at varying distances from one another.
When experts compared their measurements with theoretical calculations, they discovered that the results are approximately consistent. One slight difference was that the force between most xenon atoms was twice than what was predicted.
The research team assumes that even among noble gases, the transfer of charge occurs, causing weak covalent bonds to form. This could explain why the van der Waals force between xenon atoms had higher values.
Implications Of The Study
With this new study, physicists have proven that they can still push ahead into novel fields with the use of atomic force microscopy - a science developed three decades ago.
Scientists will also be able to study the results to better understand the physical behavior of atoms.
The details of the study are published in the journal Nature Communications.
