10 years back, researchers saw something exceptionally unusual happening when buckyballs—soccer ball shaped carbon molecules—were dumped onto a particular kind of multilayer graphene, a flat carbon nanomaterial. As opposed to moving around arbitrarily like marbles on a hardwood floor, the buckyballs suddenly amassed into single-file chains that extended over the graphene surface.
Presently, scientists from Brown University’s School of Engineering have clarified how the phenomenon works, and that clarification could make ready for another kind of controlled molecular self-assembly. In a paper distributed in Proceedings of the Royal Society A, the Brown group demonstrates that small, electrically charged creases in graphene sheets can cooperate with molecules on the surface, arranging those molecules in electric fields along the ways of the creases.
“What we show is that crinkles can be used to create ‘molecular zippers’ that can hold molecules onto a graphene surface in linear arrays,” said Kyung-Suk Kim, director of the Center for Advanced Materials Research in Brown’s Institute for Molecular and Nanoscale Innovation and the study’s senior author. “This linear arrangement is something that people in physics and chemistry really want because it makes molecules much easier to manipulate and study.”
The new paper is a follow-up to prior research by Kim’s group. In that first paper, they portrayed how tenderly squeezing sheets of layered graphene from the side makes it disfigure curiously. As opposed to framing tenderly inclining wrinkles like you may discover in a rug that has been scrunched against a divider, the compacted graphene forms pointy saw-tooth creases over the surface. They form, Kim’s research appeared, in light of the fact that the arrangement of electrons of electrons in the graphene lattice causes the curvature of a wrinkle limit along a sharp line. The creases are likewise electrically polarized, with crease crests conveying a solid negative charge and valleys conveying a positive charge.
Kim and his group figured the electrical charges along the creases may clarify the bizarre conduct of the buckyballs, somewhat in light of the fact that the sort of multilayer graphene utilized in the original buckyball experiments was HOPG, a kind of graphene that normally shapes creases when it’s created. In any case, the group expected to demonstrate unquestionably that the charge made by the creases could interface with external molecules on the graphene’s surface. That is the thing that the analysts could do in this new paper.
Their investigation utilizing density functional theory, a quantum mechanical model of how electrons are arranged in a material, predicted that positively charged crease valleys ought to make an electrical polarization in the generally electrically neutral buckyballs. That polarization should make buckyballs line up, each in a similar orientation in respect to one another and spaced around two nanometers apart.
Those theoretical predictions coordinate intently the consequences of the original buckyball experiments just as rehash experiments recently revealed by Kim and his group. The nearby assention among hypothesis and analysis affirms that graphene creases can in fact be utilized to direct molecular self-assembly, with buckyballs as well as conceivably with other molecules too.
Kim says that this molecular zippering ability could have numerous potential applications, especially in contemplating biomolecules like DNA and RNA. For instance, if DNA molecules can be extended straightly, it could be sequenced all the more rapidly and effectively. Kim and his group are at present attempting to check whether this is conceivable.
“There’s a lot of potential here to take advantage of crinkling and the interesting electrical properties they produce,” Kim said.