Detecting bombs in places such as airports could be getting easier, thanks to a new fluorescing polymer. While you might expect the material to glow in the presence of explosives, they actually cause it to stop glowing.
The polymer was developed at Cornell University by chemist William Dichtel and his graduate student, Deepti Gopalakrishnan.
Ordinarily, its random cross-linked structure lets it absorb light, transport the energy through itself, and ultimately release that energy back out as light. Should the energy meet up with even a single molecule of explosive as it moves through the polymer, however, it will be released as heat instead of light. This causes the polymer to promptly cease fluorescing.
Prof. Dichtel and Gopalakrishnan designed the polymer specifically to detect research department explosive (RDX), a very powerful and commonly-used explosive that has proven popular with terrorists. They also tested their material against commonly-carried substances such as lipstick and sunscreen to make sure that it wouldn’t react to them also, causing false alarms.
One of the polymer’s other attributes is the fact that it can detect RDX molecules not just on surfaces, but even in the air adjacent to them.
It is now hoped that the polymer could be incorporated into low-cost hand-held sensors, which could be used with or instead of bomb-sniffing dogs.
Source: Cornell University