A self-regulating shuttle for autonomous seek and destroy of microplastics from wastewater
Dennis Kollofrath, Florian Kuhlmann, Sebastian Requardt, Yaşar Krysiak, Sebastian Polarz
Abstract
Microplastics pose a significant environmental challenge, causing harm to organisms through inflammation and oxidative stress. Although traditional adsorbents effectively capture pollutants, they are limited by their localized action and require laborious recycling processes. We introduce a buoyancy-driven hybrid hydrogel that functions as a self-regulating shuttle, capable of transporting and decomposing contaminants without external intervention. By leveraging thermally switchable buoyancy, the material cyclically ascends from the seabed to the water surface, facilitating pollutant degradation, before descending to restart the process. This motion is enabled by vinyl-functionalized porous organosilica and thermoresponsive poly(N-isopropylacrylamide) (pNIPAM), which allow for reversible gas bubble storage and precise control over ascent and descent dynamics. As a demonstration, we apply this platform to microplastic decomposition, where light-induced reactive oxygen species effectively degrade collected particles. Adjustments to catalyst concentration further optimize transport kinetics, enhancing efficiency across various conditions. While microplastic remediation showcases its capabilities, this shuttle represents a broadly adaptable system for sustainable pollutant removal and environmental remediation.