Researchers at the University of Pennsylvania have devised a new method for aligning isolated single wall carbon nanotubes and, in the process, have created a new kind of material with liquid crystal-like properties, which they call nematic nanotube gels. The gels could potentially serve as sensors in complex fluids, where changes in local chemical environment, such as acidity or solvent quality, can lead to visible changes in the gel shape. The researchers describe their findings in the current issue of Physical Review Letters.
Single wall carbon nanotubes have astounded researchers with their remarkable strength and their ability to conduct heat and electricity. For many of their potential applications, however, these nanotubes work best when they are aligned parallel to one another, without forming aggregates or bundles. In solutions with low concentrations of single wall carbon nanotubes, the nanotubes are isotropic, or not oriented in a particular direction. If the concentration of the single wall carbon nanotubes is increased sufficiently, it becomes energetically favorable for the nanotubes to align. This is the nematic phase that many researchers have sought to create and utilize.
"Unfortunately, experience has shown that single wall carbon nanotubes tend to clump together or form three-dimensional networks in water at concentrations where theories otherwise predict they will form this nematic liquid crystal phase," said Arjun Yodh, senior author and a professor in Penn Department of Physics and Astronomy. "Our gels effectively increase the concentration of isolated single wall carbon nanotubes without allowing them to bundle up or form networks."
Greg Lester | University of Pennsylvania
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
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...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Physics and Astronomy
08.12.2016 | Health and Medicine
08.12.2016 | Life Sciences