A team of researchers from the U.S., China, and Saudi Arabia has developed a new kind of plastic that is able to maintain its original qualities when recycled. In their paper published in the journal Science Advances, the group describes how the new plastic is made and how well it did when tested for recyclability.

For many years, plastics have been seen as a highly desirable modern advancement—they are light, strong, bendable when needed, and can be used in a very wide variety of applications. The down side to plastics, of course, is that they do not recycle very well and they take a very long time to decay. This has led to millions of tons of plastic waste winding up in landfills and in the water table. Because of that, scientists have been hard a work looking for a new kind of plastic that has all the advantages of the old plastic but also can be easily recycled. In this new effort, the researchers claim to have developed just such a plastic.

The researchers made the new plastic by preparing a bridged bicyclic thiolactone monomer from a bio-based olefin carboxylic acid. The result was a plastic (they called PBTL) that had all the qualities of traditional plastics. They next tested their plastic by conducting bulk depolymerization at 100°C using a catalyst. Testing of the result showed the PBTL had been broken down into its original monomer. They followed that up by breaking down samples of PBTL (using a catalyst) at room temperature. And once again, close examination showed the sample had been broken down to the original monomer.

Circa 2012

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Back in 1871, James Clerk Maxwell predicted that light exerts a force on any surface it hits. This radiation pressure was experimentally discovered some 30 years later and has since emerged as a hugely important force that is now exploited in systems such as solar sails and laser cooling.

Today, John Zhang and buddies at the University of Southampton in the UK go one better. These guys predict that a far more powerful optical force can exist between a metal or dielectric plate and a metamaterial, a substance with optical properties that have been engineered to control light in specific ways.

Metamaterials can be designed so they allow tiny oscillations of electrons called plasmons to exist on their surfaces. The oscillations are tiny–measured in nanometres, that’s about the same as the wavelength of visible light.

Novel two-dimensional materials are currently a hot research topic around the world. Of special interest are van der Waals heterostructures, which are made up of individual layers of different materials held together by van der Waals forces. The interactions between the different layers can give the resulting material entirely new properties.

Double layer unlocks crucial properties

There are already van der Waals heterostructures that absorb up to 100 percent of light. Single-layers of molybdenum disulfide offer absorption capacities in this range. When light is absorbed, an electron vacates its original position in the valence band, leaving behind a positively charged hole. The electron moves to a higher energy level, known as the conduction band, where it can move freely.

MEDAN, Indonesia — Indonesia’s rumbling Mount Sinabung erupted Monday, sending a column of volcanic materials as high as 16,400 feet into the sky and depositing ash on villages.

It is the second eruption since Saturday after the volcano sat dormant for more than a year.

Falling grit and ash accumulated up to 2 inches in already abandoned villages on the volcano’s slopes, said Armen Putra, an official at the Sinabung monitoring post on Sumatra Island.