Both discoveries, published in separate studies, highlight the university’s research into nanomaterials.
Researchers at Brown University have unveiled two advancements in nanotechnology. The first, a 80-atom boron “buckyball,” represents a cousin to the carbon-based buckyball that helped launch the nanotechnology revolution. The second, a novel method for creating vertically aligned graphene nanochannels, could be useful for filtering water and other liquids of nanoscale contaminants. Both findings, detailed in separate studies, underscore research at Brown.
A Boron Buckyball Emerges
Lai-Sheng Wang, a professor of chemistry at Brown and the paper’s corresponding author, admitted he doubted the structure’s stability. I really didn’t think this structure was going to be stable and that we were going to disprove its existence,
he said. However, photoelectron spectroscopy revealed a highly symmetrical and stable configuration.
The research, published in *Chemical Science*, involved creating boron clusters by blasting a boron target with a high-powered laser and analyzing their electron binding energy spectra. The team found that the 80-atom cluster produced a spectrum with distinct peaks, suggesting a highly symmetric structure. This contradicts density functional theory (DFT) calculations, which suggest the boron buckyball shouldn’t be stable. I think the DFT calculations are wrong in this case,
Wang remarked, noting he thinks DFT has some of the bond lengths wrong for the B80 buckyball.
The implications of this discovery are that the structures could have even more interesting properties than their carbon cousins. Wang’s team has previously explored boron clusters, including a 36-atom planar disc and a 40-atom hollow cage. The 80-atom buckyball adds another layer to this work.
Graphene Nanochannels Redefined
Separate research from Brown’s School of Engineering has looked at the potential of graphene-based filtration systems. The team, including coauthor Robert Hurt, a professor in Brown’s School of Engineering, developed a method to create vertically aligned graphene membranes (VAGMEs) by stacking graphene sheets on an elastic substrate and stretching it. Releasing the tension causes the graphene to wrinkle into sharp peaks and valleys. This process aligns the nanochannels between graphene layers almost vertically.
In the last decade, a whole field has sprung up to study these spaces that form between 2-D nanomaterials,
Hurt said. The VAGMEs, as the researchers call their creation, allow water molecules to pass through narrow channels while blocking larger contaminants like organic molecules and metal ions. Proof-of-concept tests demonstrated that water vapor permeated the membrane, while hexane, a larger molecule, was filtered out.
The method’s potential applications range from industrial or household filtering applications. The research, published in *Nature Communications*, was supported by the National Institute of Environmental Health Sciences Superfund Research Program (P42 ES013660).
Controversy and Consensus
The boron buckyball study has sparked debate within the scientific community. While the experimental evidence is robust, the discrepancy with DFT calculations—the gold-standard method for determining molecular properties—raises questions about the reliability of computational models in predicting nanomaterial behavior. Wang says he hopes to work with colleagues at Brown and elsewhere to better understand why DFT might have gone awry in this case.
Both studies, however, share a common thread: they challenge conventional assumptions about nanomaterials. The boron buckyball defies expectations about boron’s ability to form stable, symmetrical structures, while the VAGMEs demonstrate a novel approach to manipulating 2D materials for practical applications.
What’s Next for Nanotechnology?
For the boron buckyball, Wang says he hopes to work with colleagues at Brown and elsewhere to better understand why DFT might have gone awry in this case. Meanwhile, the VAGME researchers plan to continue developing the technology, with an eye toward potential industrial or household filtering applications.
The broader implications of these discoveries extend beyond their immediate applications. By expanding the toolkit of nanomaterials, they could enable new technologies in energy, medicine, and environmental science.
Both breakthroughs underscore research at Brown University. From the atomic-scale engineering of boron clusters to the macro-scale applications of graphene membranes, the research highlights the interplay between theoretical predictions, experimental validation, and practical implementation.
