Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New composite material as CO2 sensor

08.06.2015

Material scientists at ETH Zurich and the Max Planck Institute of Colloids and Interfaces in Potsdam have developed a new type of sensor that can measure carbon dioxide (CO2).

Compared with existing sensors, it is much smaller, has a simpler construction, requires considerably less energy and has an entirely different functional principle. The new sensor consists of a recently developed composite material that interacts with CO2 molecules and changes its conductivity depending on the concentration of CO2 in the environment. ETH scientists have created a sensor chip with this material that enables them to determine CO2 concentration with a simple measurement of electrical resistance.

The basis of the composite material is a chain-like macromolecule (polymer) made up of salts called ionic liquids, which are liquid and conductive at room temperature. The name of the polymers is slightly misleading as they are called «poly(ionic liquid)s» (PIL), although they are solid rather than liquid.

Unexpected properties

Scientists worldwide are currently investigating these PIL for use in different applications, such as batteries and CO2 storage. From their work it is known that PIL can adsorb CO2. "We asked ourselves if we could exploit this property to obtain information on the concentration of CO2 in the air and thereby develop a new type of gas sensor," says Christoph Willa, doctoral student at the Laboratory for Multifunctional Materials.

Willa and Dorota Koziej, a team leader in the laboratory, eventually succeeded by mixing the polymers with specific inorganic nanoparticles that also interact with CO2. By experimenting with these materials, the scientists were able to produce the composite. "Separately, neither the polymer nor the nanoparticles conduct electricity," says Willa. "But when we combined them in a certain ratio, their conductivity increased rapidly."

Chemical changes in the material

It was not only this that astonished the scientists. They were also surprised that the conductivity of the composite material at room temperature is CO2-dependent. "Until now, chemoresistive materials have displayed these properties only at a temperature of several hundred degrees Celsius," explains Koziej. Thus, existing CO2 sensors made from chemoresistive materials had to be heated to a high operating temperature. With the new composite material, this is not necessary, which facilitates its application significantly.

Exactly how the CO2-dependant changes in conductivity were produced is not yet clear; however, the scientists have found indications that a chemical change induced by the presence of CO2 occurs foremost at the interface between the nanoparticles and the polymers at the nanometre scale. "We think that CO2 effects the mobility of the charged particles in the material," says Koziej.

Breathing gauges for scuba divers

With the new sensor, scientists are able to measure CO2 concentration over a wide range - from a concentration of 0.04 volume percent in the earth's atmosphere to 0.25 volume percent.

Existing devices that can detect CO2 measure the optical signal and capitalise on the fact that CO2 absorbs infrared light. In comparison, researchers believe that with the new material much smaller, portable devices can be developed that will require less energy. According to Koziej, "portable devices to measure breathing air for scuba diving, extreme altitude mountaineering or medical applications are now conceivable".

###

Literature reference

Willa C, Yuan J, Niederberger M, Koziej D: When Nanoparticles Meet Poly(Ionic Liquid)s: Chemoresistive CO2 Sensing at Room Temperature. Advanced Functional Materials 2015, 25: 2537-2542, doi: 10.1002/adfm.201500314

Media Contact

Dr. Dorota Koziej
dorota.koziej@mat.ethz.ch
41-446-336-055

 @ETH_en

http://www.ethz.ch/index_EN 

Dr. Dorota Koziej | EurekAlert!

More articles from Materials Sciences:

nachricht New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University

nachricht Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>