Air pollution sponge could clean up cars and industrial chimneys

The new sponge works well in high temperature and high humidity environments and is made of environmentally friendly materials, say the team of researchers from Fuzhou University in China.

Particulate matter from automobile exhaust and industrial chimneys poses a significant health danger to both the environment and humans, where it can impair the central nervous system and the respiratory system.

Air filters typically do not perform well in harsh environments, where high temperatures, high humidity, or the need for long periods of filtration bring added challenges.

To build a better air filter, the research team designed a three-dimensional particle capture device using a polydimethylsiloxane (PDMS) sponge.

The team tested their sponge under high temperature (250°C) and high humidity (90 per cent relative humidity) conditions that simulated an industrial high-temperature environment.

They also tested the composite sponge under the conditions required for use in filtering automobile exhaust. The sponge can be easily shaped and has structural stability, allowing it to be used in different scenarios, as needed.

In automobile exhaust tests, which simulated the exhaust emitted by automobiles during normal operation, the composite sponge achieved over 99 per cent efficiency in removing particulate matter. Even after 65 hours of filtration, the composite sponge still achieved excellent performance.

“This study provides a new idea for designing 3D high-efficiency air filters that can adapt to harsh environments,” said Yuekun Lai, a Fuzhou University professor.

Because the composite sponge has good structural stability and can also be easily shaped, it is suitable for use in applications ranging from automobile exhaust to industrial chimneys to kitchen fans.

“In the next step, our research team will explore gas filters that can adapt to higher temperatures, as well as ways to treat certain components of air pollutants, not just particulate matter filtration,” said Lai.

“Our ultimate goal is to achieve a gas filter that can be used in a variety of environments, and a high-efficiency filter material with a variety of functions.”

In June, the National Audit Office found that UK government initiatives to cut air pollution have “not moved as fast as expected” and it is unclear how current 2030 targets will be met.