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Elegant art/science: boron nitride nanotubes (BNNTs) — touted for their strength, thermal stability and insulating properties — coaxed into visually striking images

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This is the only ‘art’ boron nitride nanotube i could find,

Langmuir 2025, 41, 24, 15270–15282

A June 24, 2025 Rice University news release (also on EurekAlert) makes an art/science announcement, Note: Links have been removed,

In an elegant fusion of art and science, researchers at Rice University have achieved a major milestone in nanomaterials engineering by uncovering how boron nitride nanotubes (BNNTs) — touted for their strength, thermal stability and insulating properties — can be coaxed into forming ordered liquid crystalline phases in water. Their work, published in Langmuir, the premier American Chemical Society journal in colloid and surface chemistry, was so visually striking it graced the journal’s cover.

That vibrant image, however, represents more than just the beauty of science at the nanoscale. It captures the essence of a new, scalable method to align BNNTs in aqueous solutions using a common bile-salt surfactant — sodium deoxycholate (SDC) — opening the door to next-generation materials for aerospace, electronics and beyond.

“This work is very interesting from the fundamental point of view because it shows that BNNTs can be used as model systems to study novel nanorod liquid crystals,” said Matteo Pasquali, the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, professor of chemistry, materials science and nanoengineering and corresponding author on the study. “The main advantage is that BNNTs are relatively transparent and easily studied via visible light unlike carbon nanotubes, which form dark liquid crystals that are hard to examine via light microscopy.”

For first author Joe Khoury, the study was more than routine science. Trained as an architect in Syria, he transitioned to chemical engineering after moving to the U.S., but his background in visual design may have helped him see something others might have missed. During a routine purification step, he noticed that as water was filtered from the dispersion, the leftover material became thick and glowed under polarized light — a hallmark of liquid crystal formation. Inspired by this observation, the team hypothesized that increasing the SDC concentration would drive BNNTs to self-assemble into ordered nematic phases.

To test their hypothesis, the researchers conducted a meticulous series of experiments, preparing BNNT-SDC dispersions at varying concentrations. They used polarized light microscopy to observe the transition from disordered states to partially ordered and then fully ordered liquid crystalline phases. Cryogenic electron microscopy provided high-resolution confirmation of BNNT alignment.

Crucially, they produced the first comprehensive phase diagram for BNNTs in surfactant solutions — a predictive map that allows scientists to anticipate how BNNTs will behave at different concentration ratios.

“No one had done this before,” Khoury said. “Previous studies either worked at low BNNT concentrations or used too little surfactant. We showed that if you increase both in the right proportion, you can trigger liquid crystalline ordering without using harsh chemicals or complicated procedures.”

In addition to mapping phase behavior, the team followed a simple, reproducible method to turn these dispersions into thin, well-aligned BNNT films. Using a specialized blade to shear the material onto a glass slide, they fabricated transparent, robust films ideal for thermal management and structural reinforcement applications (think lighter, stronger and more heat-tolerant components in tech devices or aircraft). Using X-ray diffraction and electron microscopy, the team confirmed the alignment at the nanoscale level.

“We demonstrated that nematic alignment in solution can be preserved and translated into solid films,” Khoury said. “That makes this a highly scalable platform for next-gen materials.”

The study lays the groundwork for new research into lyotropic liquid crystals formed from nanorods. Its simplicity — no strong acids, no harsh conditions — makes it accessible to labs worldwide. And its implications stretch from theoretical physics to commercial materials engineering.

“This is just the beginning,” Pasquali said. “With this road map, we can now explore how to fine-tune BNNT alignment for specific applications. It’s not just about making films; it’s about understanding a whole new class of functional nanomaterials.”

Pasquali added that the beauty of the images was mesmerizing.

“When Joe sent me candidate images for the cover, I felt like I was looking at paintings by Dali or Van Gogh,” Pasquali said. “The cover image could be the tower of Barad-dur from ‘The Lord of the Rings’ painted by a surrealist artist.”

Khoury added that this research would not have been possible without the guidance and mentorship from his team and co-authors, including Pasquali; Angel Martí, professor and chair of chemistry and professor of bioengineering and materials science and nanoengineering at Rice; Cheol Park of NASA Langley Research Center; Lyndsey Scammell from BNNT LLC; and Yeshayahu Talmon at the Technion-Israel Institute of Technology, among others.

This research was supported by the Welch Foundation, BNNT LLC, the Technion Russell Berrie Nanotechnology Institute and Rice’s Electron Microscopy Center and its Shared Equipment Authority.

Caption: Matteo Pasquali, the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, professor of chemistry, materials science and nanoengineering, and first author Joe Khoury. Credit: Rice University.

Here’s a link to and a citation for the paper,

Lyotropic Liquid Crystalline Phase Behavior of Boron Nitride Nanotube Aqueous Dispersions by Joe F. Khoury, Asia Matatyaho Ya’akobi, Alina Chow, Eldar Khabushev, Irina Davidovich, Davide Cavuto, Mingrui Gong, Lyndsey R. Scammell, Cheol Park, Yeshayahu Talmon, Angel A. Martí, Matteo Pasquali. Langmuir 2025, 41, 24, 15270–15282 DOI: https://doi.org/10.1021/acs.langmuir.5c00563 Published May 5, 2025 Copyright © 2025 American Chemical Society

This paper is behind a paywall.

Boron nitride nanotubes muscle aside carbon nanotubes

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Boron nitride has been exciting members of the scientific community most recently as an alternative to carbon. A Dec. 22, 2015 news item on ScienceDaily,

When mixed with lightweight polymers, tiny carbon tubes reinforce the material, promising lightweight and strong materials for airplanes, spaceships, cars and even sports equipment. While such carbon nanotube-polymer nanocomposites have attracted enormous interest from the materials research community, a group of scientists now has evidence that a different nanotube — made from boron nitride — could offer even more strength per unit of weight.

A Dec. 22, 2015 American Institute of Physics (AIP) news release by Catherine Meyers, which originated the news item, describes why carbon nanotubes have interested scientists and the advantages presented by boron nitride nanotubes (Note: A link has been removed),

Carbon nanotubes are legendary in their strength — at least 30 times stronger than bullet-stopping Kevlar by some estimates. When mixed with lightweight polymers such as plastics and epoxy resins, the tiny tubes reinforce the material, like the rebar in a block of concrete, promising lightweight and strong materials for airplanes, spaceships, cars and even sports equipment.

While such carbon nanotube-polymer nanocomposites have attracted enormous interest from the materials research community, a group of scientists now has evidence that a different nanotube — made from boron nitride — could offer even more strength per unit of weight. …

Boron nitride, like carbon, can form single-atom-thick sheets that are rolled into cylinders to create nanotubes. By themselves boron nitride nanotubes are almost as strong as carbon nanotubes, but their real advantage in a composite material comes from the way they stick strongly to the polymer.

“The weakest link in these nanocomposites is the interface between the polymer and the nanotubes,” said Changhong Ke, an associate professor in the mechanical engineering department at the State University of New York at Binghamton. If you break a composite, the nanotubes left sticking out have clean surfaces, as opposed to having chunks of polymer still stuck to them. The clean break indicates that the connection between the tubes and the polymer fails, Ke noted.

Plucking Nanotubes

Ke and his colleagues devised a novel way to test the strength of the nanotube-polymer link. They sandwiched boron nitride nanotubes between two thin layers of polymer, with some of the nanotubes left sticking out. They selected only the tubes that were sticking straight out of the polymer, and then welded the nanotube to the tip of a tiny cantilever beam. The team applied a force on the beam and tugged increasingly harder on the nanotube until it was ripped free of the polymer.

The researchers found that the force required to pluck out a nanotube at first increased with the nanotube length, but then plateaued. The behavior is a sign that the connection between the nanotube and the polymer is failing through a crack that forms and then spreads, Ke said.

The researchers tested two forms of polymer: epoxy and poly(methyl methacrylate), or PMMA, which is the same material used for Plexiglas. They found that the epoxy-boron nitride nanotube interface was stronger than the PMMA-nanotube interface. They also found that both polymer-boron nitride nanotube binding strengths were higher than those reported for carbon nanotubes — 35 percent higher for the PMMA interface and approximately 20 percent higher for the epoxy interface.

The Advantages of Boron Nitride Nanotubes

Boron nitride nanotubes likely bind more strongly to polymers because of the way the electrons are arranged in the molecules, Ke explained. In carbon nanotubes, all carbon atoms have equal charges in their nucleus, so the atoms share electrons equally. In boron nitride, the nitrogen atom has more protons than the boron atom, so it hogs more of the electrons in the bond. The unequal charge distribution leads to a stronger attraction between the boron nitride and the polymer molecules, as verified by molecular dynamics simulations performed by Ke’s colleagues in Dr. Xianqiao Wang’s group at the University of Georgia.

Boron nitride nanotubes also have additional advantages over carbon nanotubes, Ke said. They are more stable at high temperatures and they can better absorb neutron radiation, both advantageous properties in the extreme environment of outer space. In addition, boron nitride nanotubes are piezoelectric, which means they can generate an electric charge when stretched. This property means the material offers energy harvesting as well as sensing and actuation capabilities.

The news release does note that boron nitride nanotubes have a drawback ,

The main drawback to boron nitride nanotubes is the cost. Currently they sell for about $1,000 per gram, compared to the $10-20 per gram for carbon nanotubes, Ke said. He is optimistic that the price will come down, though, noting that carbon nanotubes were similarly expensive when they were first developed.

“I think boron nitride nanotubes are the future for making polymer composites for the aerospace industry,” he said.

Here’s a link to and a citation for the paper,

Mechanical strength of boron nitride nanotube-polymer interfaces by Xiaoming Chen, Liuyang Zhang, Cheol Park, Catharine C. Fay, Xianqiao Wang, and Changhong Ke. Appl. Phys. Lett. 107, 253105 (2015); http://dx.doi.org/10.1063/1.4936755

This paper appears to be open access.