In collaboration with the Fraunhofer Institutes IOSB and IKTS, we are working in the interdisciplinary project "SOT Microplastics" on the development and testing of a robust and inline-capable analysis tool for measuring microplastic concentrations in the sea. The installation of the tool on autonomously operating underwater vehicles will enable measurements in the pelagic, i.e. in the open water area far from the shore above the benthic zone. This allows to make more efficient statements than before about the concentration and distribution of microplastics, which is a prerequisite for successfully combating marine pollution. Analytically challenging is especially the differentiation between microplastics and other particulate matter in the real environment. For this purpose, the focus is on the one hand on the possibilities and limitations of image analysis combined with AI based algorithms and on the other hand on spectroscopic methods such as Raman spectroscopy.
The change of the particle properties depending on the duration of stay in the ocean is another analytical challenge. Understanding the weathering processes that take place, e.g. as a function of exposure times to UV light or to biofilm growth, helps to train the sensors to be developed. The aging of polymer materials in the maritime environment is quantitatively investigated in both laboratory and field tests to gain an in-depth understanding of the aging processes taking place and their influencing factors. This knowledge will be used in polymer development in the future.