New Radiation Fluorescent Plastic Made From Plastic Soft Drink Bottles
See that glow, time to go! Thanks to a discovery by a Japanese research team, future wearers of radiation dosimeters could contain plastic made from soft drink bottles. The new plastic compound, dubbed “Sintirex”, uses clear PET (polyethylene terephthalate) plastic and can be produced at about one-tenth the cost of current dosimeters which use traditional plastic scintillators (above).
The modified pop-bottle plastic responds to all three main types of radiation - alpha, beta and gamma – making it ideal for use in “whole body counters” that are employed to measure a person's total internal radiation exposure.
The research team responsible for the discovery is made up of H. Nakamura, Y. Shirakawa, S. Takahashi and H. Shimizu; working under the auspices of Kyoto University, Japan's National Institute of Radiological Sciences (NIRS), and Teijin Chemicals Ltd.
The team published their findings, titled “Evidence of deep-blue photon emission at high efficiency by common plastic”, in the June 29th digital issue of the Europhysics Letters.
Team leader Hidehito Nakamura (above, left) serendipitously stumbled onto the basic properties of the new plastic last year when he noted that disposable, unmodified PET bottles would glow blue, albeit very faintly, when exposed to ionizing radiation. When Nakamura eventually determined that oxygen atoms in the plastic were reacting to radiation, he was then able to formulate increasingly sensitive plastics.
The variation of PET Nakamura's team finally arrived at actually glows more strongly than current plastic scintillators fluorescing at 10,500 photon/MeV vs 10,000 photon/MeV. Off-the-shelf PET plastic is no slouch, by the way, fluorescing at 2,200 photon/MeV.
Nakamura demonstrated the properties of the new glowing plastic at Kyoto University, where he was quick to relate the discovery to Japan's ongoing nuclear crisis. “Because of the Fukushima No. 1 Nuclear Power Plant disaster,” said Nakamura, “it's become necessary for people to keep a dosimeter close at hand. I'd like to see this plastic put to use in portable radiation detectors that could just be hung from mobile phone straps.” (via Mainichi Daily News, Chuinichi Web and IOP Science)