Nanotubes have large inner and outer surface areas that are accessible to many smaller molecules, meaning they have the potential to be developed into new types of sensors and catalysts.
Efficient techniques to synthesize nanotubes, however, are uncommon. Now, Takuzo Aida and Takanori Fukushima of the RIKEN Advanced Science Institute in Wako and colleagues from the Japan Science and Technology Agency have developed a way to controllably self-assemble graphitic molecules and platinum metals into nanotubes with specific dimensions and structural features1.
Aida and his team used a molecule called hexabenzocoronene (HBC) as the base for their new nanotubes. Consisting of thirteen aromatic benzene rings interlocked into a large, flat cyclic structure that resembles graphite, HBC is normally used as a building block for liquid crystalline semiconductors.
In 2004, Aida, Fukushima, and colleagues discovered that by adding long hydrocarbon groups and polar chains called triethylene glycol to HBC, they could make the graphitic molecule into an amphiphile2—a surfactant that can be dissolved in organic solvents. Recrystallizing a solution of the HBC amphiphiles spontaneously produced new graphitic nanotubes.
In their latest work, the researchers incorporated platinum metals into their nanotubes structures. According to Fukushima, transition metals such as platinum can add useful catalytic, electronic, luminescent, and magnetic functionalities to the nanotubes.
In order to attach platinum metals to the nanotubes, the scientists added a molecule known as pyridine, a nitrogen-containing benzene ring, to the ends of the triethylene glycol chains on the HBC amphiphile.
“Pyridine is one of the simplest and most common molecules for binding transition metals,” explains Fukushima. “We thought it fit to use such a general binding molecule in our first attempt to functionalize the HBC nanotubes with transition metals.”
By heating a solution of the HBC amphiphiles with platinum metal ions, then allowing the mixture to cool to room temperature, the scientists observed spontaneous formation of new metal-ion-coated graphitic nanotubes. Altering the assembly conditions produced tubular assemblies with different diameters, lengths, and wall widths.
“Our nanotube can serve as a unique one-dimensional nano-scaffold with not only high structural integrity, but also with beneficial electronic properties such as energy and charge transport capabilities,” says Fukushima. “We expect that the combination of these two components might lead to unprecedented phenomenon and functions.”
1. Zhang, W., Jin, W., Fukushima, T., Ishii, N. & Aida, T. Metal-ion-coated graphitic nanotubes: controlled self-assembly of a pyridyl-appended gemini-shaped hexabenzocoronene amphiphile. Angewandte Chemie International Edition 121, 4841–4844 (2009).
2. Hill, J. P., Jin, W., Kosaka, A., Fukushima, T., Ichihara, H., Shimomura, T., Ito, K., Hashizume, T., Ishii, N. & Aida, T. Self-assembled hexa-peri-hexabenzocoronene graphitic nanotube. Science 304, 1481–1483 (2004).
The corresponding author for this highlight is based at the RIKEN Functional Soft Matter Engineering Team
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine