How Rain Launches Microplastics into the Air ⚡ экспресс
The transport of microplastics upon raindrop impact onto water was investigated: drops were aimed at monolayers of microparticles (rafts) of varying size, density, and wettability under rain-like conditions. Particle rafts strongly influence splash dynamics, cavity collapse, and the formation of the Worthington jet. The onset of splashing is determined by particle-induced roughness and capillary adhesion: deeply submerged particles stabilize the spreading film, generating only microdroplets, while shallowly submerged particles destabilize the rim, causing fingering and splashing. Post-impact dynamics split into elastic and rigid regimes. Superhydrophobic rafts enable particle ejection upon impact and form particle-armored jets that fragment into liquid marbles — an efficient aerosolization pathway. Less hydrophobic rafts exhibit limited detachment but still support transport via jets. Splash thresholds and jet heights are governed by a unified geometric-inertial-capillary scaling. The results reveal the interfacial conditions for atmospheric microplastic transport and are applicable to drop-granular processes like soil erosion.
The Sun drives the water cycle, and rain returns it to the ground. But now, every drop is a tiny hammer striking the surface. Floating plastic particles (microplastics, mostly carbon) upon impact jump up like popcorn kernels on a hot skillet. But instead of popping, they get wrapped in a thin water film and turn into weightless beads. Wind catches them and carries them thousands of kilometers—from city puddles to mountain glaciers. The particles that fiercely repel water jump the highest: they bounce up several centimeters and can drift in the air.
Researchers have found a simple rule: how much plastic enters the atmosphere depends on the force of the drop's impact and the 'water-hating' nature of the particles. This helps predict what we breathe after a downpour. The same mechanism works when drops hit sand—this is how rain erodes shores and transports soil.
🎯 Plastic particles that fiercely repel water can jump up several centimeters and float in the air like miniature balloons.