Graphene Bubbles - Image Credit: The University of Manchester
Researchers at The University of Manchester state that small balloons manufactured using one-atom-thick material graphene can endure huge pressures, much more than those at the bottom of the deepest ocean. This is possible because of the extraordinary strength of graphene, which is 200 times stronger than steel.
The graphene balloons normally form when depositing graphene on flat substrates and are typically thought of as a nuisance and disregarded. The researchers at Manchester were led by Professor Irina Grigorieva, and together they observed the nano-bubbles closely and discovered their interesting properties.
These bubbles can be formed purposely to create miniature pressure machines that can withstand massive pressures. This could be a major step towards quickly identifying the way molecules respond under very high pressure.
The team discovered that the dimensions and shape of the nano-bubbles offer direct data regarding the elastic strength of graphene as well as its interaction with the underlying substrate. They also discovered that these types of balloons can be formed using other 2D crystals, such as single layers of boron nitride or molybdenum disulfide (MoS
They were able to measure the pressure applied by graphene on a material caught within the balloons, or vice versa.
To achieve this, the team indented bubbles made by graphene, monolayer boron nitride, and monolayer MoS
2 using a tip of an atomic force microscope, and measured the force that was essential to make a dent of a specific size.
These measurements exposed the fact that graphene enclosing bubbles of a micron size form pressures reaching as high as 200 MPa, or 2,000 atmospheres. Much higher pressures are anticipated for smaller bubbles.
Such pressures are enough to modify the properties of a material trapped inside the bubbles and, for example, can force crystallization of a liquid well above its normal freezing temperature.
Ekaterina Khestanova, PhD Student, University of Manchester
Sir Andre Geim, a co-author of the paper, added:
“Those balloons are ubiquitous. One can now start thinking about creating them intentionally to change enclosed materials or study the properties of atomically thin membranes under high strain and pressure.”
Video Credit: The University of Manchester - The home of graphene/Youtube.com