Jan. 11 () –
A team of researchers from South Korea and China has discovered a different and unique new form of carbon, called Carbon Porous Long Range Ordering (CPOLA).
The best known forms of carbon are graphite and diamond., but other more exotic nanoscale allotropes of carbon exist as well. Among them are graphene and fullerenes, which are sp2 hybridized carbons with zero (flat) or positive (sphere-shaped) curvatures.
Meanwhile, sp2 hybridized carbon with negative curvature, called schwarzite, has been theoretically proposed, and its discovery has been the dream of some scientists in the field of carbon materials. It has been found that carbon can be patterned into some of the periodic pores of certain zeolites by vapor deposition, but the patterning is incomplete because some pores are too narrow. This has thwarted the fabrication of carbon schwartzites by quenching routes.
Now, a team of researchers from the Center for Multidimensional Carbon Materials at the Institute of Basic Sciences (IBS) in South Korea, led by Director Rodney Ruoff, and their colleagues from the University of Science and Technology of China, led by Prof. Yanwu ZHU, have reported in Nature of the discovery of the new form of carbon.
“Professor Ruoff explained to us his interest in the minimal triply periodic surfaces described by the mathematician Schwartz, and how trivalently bonded carbon can lead to identical structures in principle in mathematical constructions,” says Zhu, who led the USCT team– Now people are talking about schwarzite carbon structures, which can also be called negative curvature carbon. Years ago I told you that it was an exciting research topic and that it would be possible to find a way to collaborate on your suggestion“, remember.
This new form of carbon was produced using as base material C60 fullerene powder (buckminsterfullerene, also called “buckyball molecules”). The C60 was mixed with alpha-Li3N (“alpha lithium nitride”) and then heated to moderate temperatures while held at one atmosphere of pressure. Alpha-Li3N was found to catalyze the breaking of some of the C60 carbon-carbon bonds, and then new CC bonds were formed with neighboring C60 molecules by transferring electrons to the C60 molecules.
“In this particular effort, Professor Zhu and the USTC team used a powerful electron transfer agent (alpha-Li3N) to drive the formation of a new type of carbon from crystalline fullerene,” explains Ruoff.
X-ray diffraction, Raman spectroscopy, magic angle rotation solid-state nuclear magnetic resonance spectroscopy, aberration-corrected transmission electron microscopy, and light scattering were used to understand the structure of this new form of carbon. neutrons.
Numerical simulations based on a type of neural network modeling, combined with the aforementioned experimental methods, show that the new carbon is a metastable structure produced during the transformation of “fullerene-like” to “graphene-like” carbons. And knowing its electrical properties is important to elucidate the possible applications of this new type of carbon, the researchers add.
“While this beautiful new type of carbon has many exciting characteristics, it is not a schwarzite carbon so that experimental challenge is still on the horizon,” Ruoff said. “In fact, this carbon is something different and unique: opens up entirely new possibilities in new directions for carbon materials.”
The preparation of this new type of carbon paves the way for the discovery of other crystalline carbons from C60(s) – and perhaps from other fullerenes like C70, C76, C84, etc. Another interesting option would be to include another element. This can be done by starting with the “endohedral” fullerenes, they note.
Thus, the team sees possible applications in the collection, transformation and storage of energy; in catalysis to generate chemical products; and for the separation of molecular ions or gases.
Another important aspect highlighted by the authors of the study is the scalability of the synthesis. In this sense, Zhu points out that it is easily scalable to the kilogram scale and, with continuous production processes, it may be possible to achieve ton-scale production.
