Diffusion Sampler for Acidic Ultrafine Particles in the Atmosphere

More than 90% of atmospheric particulate matter is made up of ultrafine particles (i.e. particles of 0.1 micrometer or smaller in diameter). Research findings indicate that the concentration of ultrafine particles in the air is closely related to the incidence and mortality rate of diseases, especially those of the respiratory and cardiovascular systems. However, owing to the lack of effective techniques for measuring acidic ultrafine particles, research in this area remains at an early stage.

The PolyU research team has developed a novel low-flow diffusion sampler based on diffusion deposition. Using iron nano-film detectors, the device can identify acidic ultrafine particles in the air that flows through it, thereby determining the concentration and size distribution of particles.