Most of us are familiar with the smell of chemicals – soap, drain cleaner, or nail polish remover, etc. These smells are actually molecules of chemicals that have volatilized (turned into a gas) and permeate the air. Unfortunately, many of these volatile organic compounds (VOCs) are toxic. For a long time, scientists have been trying to develop a sensor that would detect VOCs and allow the air to be cleared or the area temporarily evacuated.
I was therefore pleased to read about a recent development from Korea, where a team of chemists have prepared fibers that are embedded with conjugated polymers. I’ve discussed conjugated polymers here before; they’re intensely fascinating materials that are usually fluorescent. The scientists weave swatches of cloth from these special fibers and then use them to test for a variety of solvent vapors. Depending on the chemical makeup of the fiber, the color change upon exposure to a particular vapor is very distinctive. for example, one of their treated cloth swatches turned instantly from blue to red when exposed to a small amount of chloroform vapor. This would give workers in the immediate area of a chemical spill time to evaluate the leak and to begin cleanup procedures, if necessary. The sensing textile can then be regenerated back to its normal blue color simply by drying it in solvent-free air or (better yet) by spraying it with nitrogen from a compressed gas cylinder.
Since many VOCs are being labeled as bad for human health, it’s reassuring that we have ways to detect these elusive compounds, and to take action if we deem it necessary.
These published scientific results were very informative and was a fantastic example of applied research. Workers will be safer, and everyone will soon be able to monitor their own exosure to potentially harmful chemical vapors.
The source of this article can be found at: Yoon, et al. “Colorimetric Sensors for Volatile Organic Compounds (VOCs) Based on Conjugated Polymer-Embedded Electrospun Fibers”. Journal of the American Chemical Society, 2007, 129, 3038-3039.