“Two-dimensional nanomaterials are extraordinarily skinny — solely a number of atoms thick — sheet-shaped supplies,” mentioned Utana Umezaki, a Rice graduate scholar who’s a lead writer on a research revealed in ACS Nano. “They behave very otherwise from supplies we’re used to in each day life and might have actually helpful properties: They will stand up to a number of pressure, resist excessive temperatures and so forth. To reap the benefits of these distinctive properties, we’ve got to search out methods to show them into larger-scale supplies like movies and fibers.”

To be able to keep their particular properties in bulk kind, sheets of 2D supplies should be correctly aligned — a course of that usually happens in answer part. Rice researchers targeted on graphene, which is made up of carbon atoms, and hexagonal boron nitride, a fabric with an analogous construction to graphene however composed of boron and nitrogen atoms.

“We have been notably fascinated about hexagonal boron nitride, which is usually referred to as ‘white graphene’ and which, not like graphene, would not conduct electrical energy however has excessive tensile energy and is chemically resistant,” mentioned Angel Martí, a professor of chemistry, bioengineering, supplies science and nanoengineering and chair of Rice’s chemistry division. “One of many issues that we realized is that the diffusion of hexagonal boron nitride in answer was not very nicely understood.

“Actually, after we consulted the literature, we discovered that the identical was true for graphene. We could not discover an account of diffusion dynamics on the single molecule stage for these supplies, which is what motivated us to deal with this downside.”

The researchers used a fluorescent surfactant, i.e. glowing cleaning soap, to tag the nanomaterial samples and render their movement seen. Movies of this movement allowed researchers to map out the trajectories of the samples and decide the connection between their measurement and the way they transfer.

“From our remark, we discovered an attention-grabbing development between the velocity of their motion and their measurement,” Umezaki mentioned. “We might specific the development with a comparatively easy equation, which implies we are able to predict the motion mathematically.”

Graphene was discovered to maneuver slower within the liquid answer, probably because of the truth that its layers are thinner and extra versatile than hexagonal boron nitride, giving rise to extra friction. Researchers consider that the system derived from the experiment could possibly be used to explain how different 2D supplies transfer in related contexts.

“Understanding how diffusion in a confined surroundings works for these supplies is necessary as a result of — if we wish to make fibers, for instance — we extrude these supplies by way of very skinny injectors or spinnerets,” Martí mentioned. “So this is step one towards understanding how these supplies begin to assemble and behave when they’re on this confined surroundings.”

As one of many first research to research the hydrodynamics of 2D nanosheet supplies, the analysis helps fill a niche within the area and could possibly be instrumental to overcoming 2D materials fabrication challenges.

“Our last goal with learning these constructing blocks is to have the ability to generate macroscopic supplies,” Martí mentioned.

Anatoly Kolomeisky, professor of chemistry and chemical and biomolecular engineering at Rice, and Matteo Pasquali, the A.J. Hartsook Professor of Chemical and Biomolecular Engineering and professor of chemistry and of supplies science and nanoengineering, are corresponding authors on the research.

The analysis was supported by the Nationwide Science Basis (1807737, 2108838), the Air Power Workplace of Scientific Analysis (FA9550-19-1-7045) and the Welch Basis (C-2152, C-1668, C-1559).