The Department of Science and Technology (DST) said on Friday that our scientists have created a thermally stable and cost-effective electronic polymer-based sensor for quickly detecting nitro-aromatic compounds used in high-energy explosives for the first time.
Criminal investigations, minefield remediation, military applications, munitions cleanup sites, security applications, and chemical sensors all play a part in detecting explosives without destroying them, according to the report.
Instrumental methods are typically used to analyse explosive poly-nitroaromatic compounds. However, the DST said that the needs for rapid decision-making at criminology labs or reclaimed military sites, or to identify bombs in extremists’ hands, frequently necessitate simple, inexpensive, and selective field methods that are non-destructive in character.
It is said that non-destructive detection of nitroaromatic compounds (NACs) is challenging.
Detection based on conducting property has not been studied before, it added, while previous research has mainly focused on photoluminescent properties.
According to the department, detection based on conducting property aids in the creation of portable detection equipment with findings visible through the LED.
To overcome these drawbacks, a group of scientists led by Neelotpal Sen Sarma of the Institute of Advanced Study in Science and Technology, Guwahati, an autonomous DST institute, developed a layer-by-layer (LBL) polymer detector made up of two organic polymers: poly-2-vinyl pyridine with acrylonitrile (P2VP-Co-AN) and copolysulfone of cholesteryl methacrylate with hexane
In the presence of extremely low concentrations of NACs vapour, this experiences a dramatic shift in impedance (resistance in an ac circuit) within a few seconds, according to the DST.
Picric acid (PA) was selected as the model NAC in this study, and a simple and cost-effective electrical prototype for optical detection of PA was created. It was announced that the team has submitted a patent for the new technology, which was sponsored by the Department of Electronics and Information Technology.
“An electronic detecting device based on a polymer gas sensor can identify the explosion on-site rapidly,” Sarma said.
According to the DST, the sensor device is made up of three layers: PCHMASH, a polymer copolymer of cholesteryl methacrylate with 1-hexene (PCHMASH), and a copolymer of poly-2-vinyl pyridine with acrylonitrile, sandwiched between two P2VP-Co-AN outer layers by stainless steel mesh.
The system’s sensitivity is evaluated by measuring the change in impedance response over time (seconds) in the presence of the analyte’s vapour (picric acid), according to the report.
The tri-layer polymer matrix was discovered to be a highly effective nitroaromatic chemical molecular sensor. The sensor is basic and reversible in nature, and its response does not change when the working temperature changes, even when other common chemicals and humidity are present.
The gadget may be used at room temperature, has a quick reaction time, and has little chemical interference. According to the DST, the manufacturing is extremely easy, is unaffected by humidity, and the cholesterol-based polymers utilised are biodegradable.
Source: Business Standard