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 From foam to bone: Plant cellulose can pave the way for healthy bone implants
19.03.2019 | University of British Columbia

nachricht Additive printing processes for flexible touchscreens: increased materials and cost efficiency
19.03.2019 | INM - Leibniz-Institut für Neue Materialien gGmbH

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Laser processing is a matter for the head – LZH at the Hannover Messe 2019

25.03.2019 | Trade Fair News

A Varied Menu

25.03.2019 | Life Sciences

‘Time Machine’ heralds new era

25.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>