Some household surfaces are more prone to collecting dust than others, a phenomenon explained by materials engineer Nisa Salim from Swinburne University of Technology. While factors like an object's placement and airborne particle levels contribute, certain materials inherently attract more dust.
Large dust particles settle due to gravity, but finer particles are influenced by van der Waal forces, which are weak molecular attractions. These forces strengthen with increased contact between a particle and a surface. Rough, porous materials offer more contact points, allowing dust to adhere more readily.
Beyond molecular attraction, electrostatic forces can also draw dust to surfaces. When materials rub together, they can transfer electrons, leaving surfaces charged. Many dust particles also carry charges, leading them to be attracted to these charged surfaces. Materials such as acrylic, PVC, polyester, and polypropylene are poor electrical conductors, meaning they retain electrical charges for longer, thus attracting more electrostatically charged dust. In contrast, good conductors like metal neutralise charges quickly, collecting less of this type of dust.
Humidity levels also affect dust accumulation. According to Salim, water molecules in the air help electrical charges dissipate from surfaces. During colder, drier periods or in air-conditioned environments, reduced moisture means electrostatic charges persist longer, causing dust to cling more stubbornly.
An experiment involving a coat rack found that running a dehumidifier, which creates drier conditions, resulted in a dustier surface. Conversely, using an air purifier noticeably reduced dust collection on the coat rack.