The introduction of purified carbon nanotubes appears to have a beneficial effect on the early growth of wheatgrass, according to scientists. But in the presence of contaminants, those same nanotubes could do great harm.

The Rice University lab of chemist Andrew Barron grew wheatgrass in a hydroponic garden to test the potential toxicity of nanoparticles on the plant. To their surprise, they found one type of particle dispersed in water helped the plant grow bigger and faster.

They suspect the results spring from nanotubes’ natural hydrophobic (water-avoiding) nature that in one experiment apparently facilitated the plants’ enhanced uptake of water.

The lab mounted the small-scale study with the knowledge that the industrial production of nanotubes will inevitably lead to their wider dispersal in the environment. The study cites rapid growth in the market for nanoparticles in drugs, cosmetics, fabrics, water filters, and military weapons, with thousands of tons produced annually.

Despite their widespread use, Barron says few researchers have looked at the impact of environmental nanoparticles—whether natural or human-made—on plant growth.

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Image: APPER/Wikimedia Commons

Carbon nanotubes have a potentially wide variety of applications due to their strength, flexibility, and other promising properties. While many researchers have been focused on applying carbon nanotubes in nanotechnology and electronics, ECS members Kris Dahl and Mohammad Islam are looking to give the nanotubes a new use in medical applications.

Dahl, a chemical and biomedical engineer; and Islam, a materials scientists; are taking their respective skills and putting them to use in the novel interdisciplinary development, making possible carbon nanotubed-based structures for drug delivery.

This from Carnegie Mellon University:

Picture feeding a dog a pill. In order to do so, one would wrap it in cheese to mask the medicine and make it more appealing. In a similar vein, to enhance drug delivery, Dahl and Islam have engineered proteins that wrap around the drug-coated carbon nanotubes. The cells, which love these proteins, more readily take up the drug—much as a dog would more readily eat the cheese-coated pill.

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A research team, including ECS members Stephen Doorn and Erik H Hároz, has created flexible, wafer-scale films of highly aligned and closely packed carbon nanotubes thanks to a simple filtration process. In a discovery that was previously though impossible, the researchers found that in the right solution and under the right conditions, the tubes can assemble themselves by the millions into long rows.

(ICYMI: Get the freshman 101 on carbon nanotubes from nanocarbons expert Bruce Weisman.)

“Once we have centimeter-sized crystals consisting of single-chirality nanotubes, that’s it,” said Junichiro Kono, Rice University physicist leading the study. “That’s the holy grail for this field. For the last 20 years, people have been looking for this.”

Bruce Weisman, chemistry and materials science professor at Rice University, is internationally recognized for his contributions to the spectroscopy and photophysics of carbon nanostructures. He is a pioneer in the field of spectroscopy, leading the discovery and interpretation of near-infrared fluorescence for semiconducting carbon nanotubes. Aside from his work at Rice University, Weisman is also the founder and president of Applied NanoFluorescence.

Weisman is currently the Division Chair of the ECS Nanocarbons Division, which will be celebrating 25 years of nanocarbons symposia at the upcoming 229th ECS Meeting in San Diego, CA, May 2016. Since starting in 1991, the symposia has totaled 5,853 abstracts at ECS biannual meetings, with Nobel Laureate Richard Smalley delivering the inaugural talk.

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The space elevator: a concept first conceptualized in the late 19th century that has been highly disputed and contested over the years. Many scientists and research institutions believe that the space elevator can be actualized in our lifetime. Up until 2014, Google X’s Rapid Evaluation R&D team was still working on bringing this concept to life. However, the project came to a halt due to the lack of advancement in the field of carbon nanotubes—the material that many deemed necessary to meet the strength requirements for the space elevator.

But work in the field of carbon nanotubes pressed on, and in 2014 diamond nanothreads were first synthesized. With strength properties similar to that of carbon nanotubes, researchers are once again interested in the development of the space elevator.

After testing from the Queensland University of Technology in Australia, researchers are putting a breath of fresh air into the space elevator with large scale diamond nanothreads, which may potentially be the world’s strongest substance.

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Carbon nanotubes, seamless cylinders of graphene, do not display a total dipole moment. While not zero, the vector-induced moments cancel each other out.
Image: Rice University

Theoretical physicist at both Rice University and institutes in Russia have concluded that the best way to control graphene’s electrical qualities is to flex the material.

Rice University’s Boris Yakobson and his lab are collaborating with Moscow researchers to calculate the electrical properties of nanocones, which should be universal for other forms of graphene.

(PS: You can take a look at some of Yakobson’s past meeting abstracts in the Digital Library.)

This from Rice University:

The researchers discovered it may be possible to access what they call an electronic flexoelectric effect in which the electronic properties of a sheet of graphene can be manipulated simply by twisting it a certain way. The work will be of interest to those considering graphene elements in flexible touchscreens or memories that store bits by controlling electric dipole moments of carbon atoms, the researchers said.

Read the full article here.

“While the dipole moment is zero for flat graphene or cylindrical nanotubes, in between there is a family of cones, actually produced in laboratories, whose dipole moments are significant and scale linearly with cone length,” Yakobson said.

ICYMI: Check out our podcast, “A Word About Nanocarbons,” featuring another Rice University carbon nanotube expert, Dr. Bruce Weisman.

Interested in carbon nanotubes, fullerenes, and nanocarbons? Make sure to check out ECS’s Nanocarbons Division!

While CNT alignment is still not perfect, it will now be able to be scaled up for large-scale production.
Source: North Carolina State University

A new process called “microcombing” has been developed to created ultra-strong and highly conductive carbon nanotubes (CNTs).

The films produced from the microcombing technique could have practical applications in improving electronics and aerospace technology.

“It’s a simple process and can create a lightweight CNT film, or ‘bucky paper,’ that is a meter wide and twice as strong as previous such films—it’s even stronger than CNT fibers,” said Yuntian Zhu, Distinguished Professor of Material Science and Engineering at NC State.

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Scientists have developed a new type of energy-efficient flat light source with a power consumption about a hundred times lower than that of an LED.
Credit: N. Shimoi/Tohoku University

Scientists all around the globe are constantly looking for a way to create the even-better-bulb of tomorrow. In order to do this, researchers are looking toward carbon electronics.

This from the American Institute of Physics:

Electronics based on carbon, especially carbon nanotubes (CNTs), are emerging as successors to silicon for making semiconductor materials, and they may enable a new generation of brighter, low-power, low-cost lighting devices that could challenge the dominance of light-emitting diodes (LEDs) in the future and help meet society’s ever-escalating demand for greener bulbs.

Read the full article here.

With this in mind, scientists from Tohoku University have developed a new type of energy-efficient flat light source with a very low power consumption that comes in around 0.1 Watt for every hour of operation. This is about one hundred times lower than that of an LED.

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