Microplastic pollution is on the rise, especially in waterways. Microfibers — millimeters in length but only microns in diameter — are especially prevalent, as they get washed out of synthetic clothing. Collecting these pollutants first requires understanding how they move and cluster in turbulent flows. Researchers investigated that using a small water channel and high-resolution cameras.
The team followed microfiber strands as they moved through turbulence, paying special attention to how the fibers tumbled (rotating about their short axis) and spin (rotating around their long axis). How much fibers tumbled depended on the turbulence level; with more intense turbulence, the fibers tumbled more. Rates of spinning, they found, were consistently even higher than those for tumbling. By better understanding how microfibers behave in turbulence, we’ll be able to, for example, predict how far plastics will travel before settling to the ocean floor. (Image credit: Adobe Stock Photos; research credit: V. Giurgiu et al.; via APS Physics)