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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 30: Charged Soft Matter, Polyelectrolytes and Ionic Liquids II
CPP 30.3: Talk
Wednesday, March 20, 2024, 15:30–15:45, H 0107
Attractive Interactions of Eco-corona Covered Microplastic Particles in Aqueous Environment — •Thomas Witzmann1, Günter Auernhammer1, Andreas Fery1, 2, Simon Wieland3, and Holger Kress3 — 1Leibniz Institute of Polymer Research Dresden — 2Physical Chemistry of Polymeric Materials, Technische Universität Dresden — 3Biological Physics, University of Bayreuth
Microplastic particles in the environment are covered by a so-called eco-corona. The eco-corona is made up of natural organic matter (NOM) like biomolecules, humic substances and other natural molecules. NOM changes the surface properties of microplastic particles and therefore the interaction with other surfaces in the aqueous environment influencing their aggregation behaviour. Using Colloidal Probe-AFM we studied the interactions of eco-corona covered microplastic particles. Measurements were performed in different ionic concentrations to mimic changing environmental conditions and to step-wise reduce electrostatic contributions. We found that the eco-corona is able to "pull" at the colloidal probe by polymer bridging. This bridging energy decreases with increasing eco-corona coverage of the probe surface. Bridging was present at 1, 10 and 150 mM KCl. No bridging occurred at 0.1 mM KCl. In conclusion, we show that the eco-corona is able to form polymer bridges and "pull" surfaces towards itself. This mechanism may contribute substantially to microplastic aggregation in the aqueous environment.
Keywords: Eco-corona; Microplastic; Polymer Bridging; Adhesion