doi:10.1038/nindia.2013.80 Published online 19 June 2013
Researchers have designed a new kind of sensor that can detect minute traces of chloroform in various biological and environmental samples. The sensor was made from a polymer nanocomposite consisting of organic-acid-modified multi-walled carbon nanotubes.
Chloroform may be released into the air through its formation in the chlorination of drinking water, wastewater and swimming pools. It also emanates from pulp and paper mills, hazardous-waste sites and sanitary landfills. Chloroform affects the central nervous system and the liver causing hepatitis and jaundice. In addition, animal studies have shown that it can cause kidney and liver tumours. It is thus necessary to detect traces of chloroform. However, current techniques for monitoring chloroform involve complex steps and are not selective.
To develop a simple and effective chloroform sensor, the researchers synthesized a nanocomposite by mixing the polymer polyaniline with organic-acid-modified multi-walled carbon nanotubes. They compared the response of the prepared nanocomposite to different chlorinated methane vapours with that of the pure polymer.
The nanocomposite sensor exhibited better selectivity to chloroform vapour in the presence of the other chlorinated methane vapours than the pure polymer. The researchers investigated the effect of nanotube concentration on detection sensitivity and [Consider adding this.] found that the nanocomposite containing 2 percent weight of multi-walled carbon nanotubes exhibited the highest chloroform detection sensitivity.