Studying the effects of microgravity on materials has many potential benefits and could potentially lead to the discovery of new materials. But conducting experiments in space obviously comes with huge costs. To replicate the conditions found in places such as the International Space Station, the Barcelona team used custom-made microfluidic devices and created 2D porous crystalline molecular structures formed of one layer of atoms, similar to the structure of graphene.
“We confirmed that the experiments under these simulated microgravity conditions have unprecedented effects on the orientation, compactness and generation of 2D crystalline and porous materials,” explained Josep Puigmartí Luis, ICREA researcher at the university’s Department of Physical Chemistry and member of the Institute of Theoretical and Computational Chemistry (IQTCUB).
The microfluidic device consist of two interlinked substrates with a fine silicone film of variable thicknesses. One of the surfaces has two machine inlet ports that enable the complete filling of the microfluidic environment and prevent the appearance of air bubbles.
The system enabled the growth of a 2D metalorganic framework prototype (MOF), which forms a millimetric layer without defects and which has conductivity properties. Using the ALBA Synchrotron on the outskirts of Barcelona, the team was able to study crystallinity, structure and orientation of the 2D material. The work appears on the cover of the latest edition of Advanced Materials.
"The spatio-temporal control in the growth of this material obtained with the simulated microgravity conditions is unprecedented in the scientific literature. The microfluidic device has allowed us to develop centimetre-long thin layers and study the previously undescribed electronic properties of the material," said Noemí Contreras Pereda, from the Catalan Institute of Nanoscience and Nanotechnology.
“This new simulated microgravity system will be like a ‘playground’ for chemists, physicists, and materials scientists who want to process 2D functional devices and materials.”