Page 68 - Plastics News July 2019

teChNoLogy

Rodriguez, who worked on the project as an undergraduate, emergent patterns are in fact thermodynamically stable,
explains that the team prepared many of these block and revealed the conditions under which the new patterns
copolymer samples and studied them under a scanning would form." Ding says "We understand the system fully in
electron microscope. Yi Ding, who worked on this for his terms of the thermodynamics," and the self-assembling
doctoral thesis, "started looking over and over to see if any process "allows us to create fine patterns and to access some
interesting patterns came up," she says. "That's when all new symmetries that are otherwise hard to fabricate." He
of these new findings sort of evolved." The resulting odd says this removes some existing limitations in the design of
patterns are "a result of the frustration between the pattern optical and plasmonic materials, and thus "creates a new
the polymer would like to form, and the template," explains path" for materials design.So far, the work the team has
Alexander-Katz. That frustration leads to a breaking of the done has been confined to two-dimensional surfaces, but in
original symmetries and the creation of new subregions ongoing work they are hoping to extend the process into the
with different kinds of symmetries within them, he says. third dimension, says Ross. "Three dimensional fabrication
"That's the solution nature comes up with. Trying to fit in would be a game changer," she says. Current fabrication
the relationship between these two patterns, it comes techniques for microdevices build them up one layer at a
up with a third thing that breaks the patterns of both of time, she says, but "if you can build up entire objects in 3-D
them." They describe the new patterns as a "superlattice." in one go," that would potentially make the process much
Having created these novel structures, the team went on more efficient. The research was funded by the Office of
to develop models to explain the process. Co-author Karim General Sciences of the U.S. Department of Energy. The
Gadelrab PhD '19, says, "The modeling work showed that the team also included graduate student Hejin Huang.

Black plastics could create renewable energy

esearch from Swansea University looks a piece of chicken wire wrapped into a cylinder
Rhas found how plastics commonly and when carbon is arranged like this it can conduct both
found in food packaging can be heat and electricity. These two different forms of energy
recycled to create new materials like are each very important to control and use in the right
wires for electricity and could help to quantities, depending on your needs. "Nanotubes can be
reduce the amount of plastic waste in used to make a huge range of things, such as conductive
the future.While a small proportion films for touchscreen displays, flexible electronics fabrics
of the hundreds of types of plastics that create energy, antennas for 5G networks while NASA
can be recycled by conventional has used them to prevent electric shocks on the Juno
technology, researchers found that spacecraft."
there are other things that can be done to reuse plastics During the study, the research team tested plastics, in
after they've served their original purpose.The research, particular black plastics, which are commonly used as
published in The Journal for Carbon Research, focuses on packaging for ready meals and fruit and vegetables in
chemical recycling which uses the constituent elements supermarkets, but can't be easily recycled. They removed
of the plastic to make new materials.While all plastics the carbon and then constructed nanotube molecules
are made of carbon, hydrogen and sometimes oxygen, from the bottom up using the carbon atoms and used
the amounts and arrangements of these three elements the nanotubes to transmit electricity to a light bulb in a
make each plastic unique. As plastics are very pure and small demonstrator model. Now the research team plan
highly refined chemicals, they can be broken down into to make high purity carbon electrical cables using waste
these elements and then bonded in different arrangements plastic materials and to improve the nanotube material's
to make high value materials such as carbon nanotubes.
electrical performance and increase the output, so they
Dr Alvin Orbaek White, a Sêr Cymru II Fellow at the Energy are ready for large-scale deployment in the next three
Safety Research Institute (ESRI) at Swansea University years.Dr Orbaek White said: "The research is significant
said: "Carbon nanotubes are tiny molecules with incredible as carbon nanotubes can be used to solve the problem of
physical properties. The structure of a carbon nanotube overheating of electricity cables overheating .

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