Engineers have developed a method for manufacturing gas analyzing threads that change the color when various hazardous gases are found in air or under water. They can be woven into clothing, do not wet and allow you to visually identify even complex mixtures of poisonous substances.
According to scientists from the University of Tafts, the sensitivity of the threads is not inferior to electronic devices and they can be applied without additional equipment or special training.
To create them, researchers dipped the thread into various dyes based on manganese, methyl red and brommatome blue. Then treated with acetic acid, from which the fiber swelling, and the surface became coarse, improving the interaction of indicators with the fibers of the base. After that, the polydimethylsiloxane (PDMS) was covered, creating a flexible physical protective layer transmitting gas, but repulsing water, preventing the dyes washing.
Researchers say that since the indicators used are working in different ways, it is possible to determine gases with various chemical properties, and the use of simple dyes provides a wide selection of functional chemicals.
Changing the color of the gas analyzing thread depends on the gas concentration. If you need to clarify the quantitative assessment of the indicator or interpretation of the color signatures of several «smart» threads and analytes, you can use applications on the smartphone.
In the course of underwater tests, engineers successfully recorded the presence of dissolved ammonia. According to them, such sensors can be built into clothing or create tissue from them using industrial, military, rescuers and health workers as an affordable security.
Previously, scientists have found that cellulose, impregnated with a special polymer mixture,