Category Chemistry/Nanotechnology

Illustration of a graphene nanoribbon with zigzag edges and the precursor molecules used in its manufacture. Electrons on the two zigzag edges display opposite directions of rotation (spin) — “spin-up” on the bottom edge (red) or “spin-down” on the top edge (blue). Credit: EMPA

Scientists have now managed to synthesise GNR with perfectly zigzagged edges using suitable carbon precursor molecules and a perfected manufacturing process. The zigzags followed a very specific geometry along the longitudinal axis of the ribbons. This is an important step, because researchers can thus give graphene ribbons different properties via the geometry of the ribbons and especially via the structure of their edges.

With molecules in a U-shape, which they allowed to grow together to form a snake-like shape, ...

ORNL’s tough new plastic is made with 50 percent renewable content from biomass. Credit: Oak Ridge National Laboratory, U.S. Dept. of Energy; conceptual art by Mark Robbins (hi-res image)

Your car’s bumper is probably made of a moldable thermoplastic polymer called ABS, shorthand for its acrylonitrile, butadiene and styrene components. Light, strong and tough, it is also the stuff of ventilation pipes, protective headgear, kitchen appliances, Lego bricks and many other consumer products. Useful as it is, one of its drawbacks is that it is made using chemicals derived from petroleum.

Now, Dept of Energy’s Oak Ridge National Lab researchers have made a better thermoplastic by replacing styrene with lignin, a brittle, rigid polymer that, with cellulose, forms the woody cell walls of plants...

The nozzle firing a jet of carbon nanotubes with helium plasma off and on. When the plasma is off, the density of carbon nanotubes is small. The plasma focuses the nanotubes onto the substrate with high density and good adhesion. Credit: NASA Ames Research Center

New method can deposit nanomaterials onto flexible surfaces such as paper or cloth and 3-D objects.. The technique could make it easier and cheaper to build devices like wearable chemical and biological sensors, flexible memory devices and batteries, and integrated circuits.

One of the most common methods to deposit nanomaterials- such as a layer of nanoparticles or nanotubes -onto a surface is with an inkjet printer similar to an ordinary printer found in an office. But inkjets can’t print on textiles etc, let alone 3-D objects...