German researchers are testing paints that promise to purify and rid the air of nitrogen oxide.
Using a new procedure, researchers at the Fraunhofer Institute for Molecular Biology and Applied Ecology IME in Schmallenberg, Germany, are examining the effectiveness of photo-catalytic coatings at removing nitrogen oxides, a key component in smog.
© Wolfram Scheible/Fraunhofer
Coated samples will be measured at scheduled intervals over the next two years to see how effective they are at mitigating NOx and other pollutants.
The two-year project is also testing how coated building test panels perform over time, according to the researchers.
Nitrogen oxide (NOx) reacts with sunlight to form photochemical pollution. It is generated from combustion and is present in especially high concentrations in urban areas.
Testing Process in Urban Area
“Coatings that are photo-catalytically active can help to reduce nitrogen oxides,” explains Dr. Michael Hüben, of the research team. “There are already a number of products available for the photo-catalytic coating of surfaces, but the measurement method standardized according to ISO 22197-1 cannot be applied to all problems.”
Hüben and his team developed a special measurement cell to test samples. The team says it will place coated “weathering noise barrier” samples at the A 4 interstate in Bergisch Gladbach, Germany.
The samples were coated with titanium dioxide that acts as a catalyst in the presence of sunlight, breaking down the NOx into nitrate, according to the researchers.
“The photo-catalytic activities of the samples are determined using a flow-through process,” according to the scientist.
During the next two years, the team will determine regularly how much NOx is being removed. The process is expected to determine a “solid basis for the long-term effects of the coatings,” the researchers said.
“Only then will we be sure that the coatings really do help and that larger surfaces, such as entire housing tracts, can be economically furnished with coats that are photo-catalytically effective,” the team said.
The German Federal Ministry of Transport and the German Federal Highway Research Institute are sponsoring and supporting the project.
Fraunhofer researchers will formally introduce the new test procedure at the trade fair BAU 2013, set for Jan. 14-19 in Munich. The event is billed as the “World’s Leading Trade Fair for Architecture, Materials, Systems.”
Interior Tests, Too
The researchers are also developing measurements to work up standards and certifications for interior coatings that promise to improve air quality, according to the team.
Other photo-catalytic applications for both the interior and exterior, using a stylized house, will be presented at BAU 2013.