Hold on Tight and Let Go – Electrically-responsive adsorption and desorption on polypyrrole

Separation is essential in food processing, from purifying valuable ingredients to converting waste into useful products. Conventional high-precision methods, such as chromatography, often rely on chemical changes to release captured molecules (e.g., pH or salt), which can be costly and environmentally harmful. This thesis explores a more sustainable alternative: electrical stimulation. To achieve this, we investigated polypyrrole, a smart polymer that responds to electrical signals. With electricity, we can change the properties of this material, allowing control over the interaction between the material and specific target molecules.

We studied the growth of polypyrrole films, ways to tune their functionality, and whether electrical signals allow controlled binding and release of target molecules. By studying the underlying switching mechanism, we aimed to design polypyrrole surfaces for separating both charged (proteins) and neutral (flavor compounds) molecules. Finally, we propose pathways toward enhancing the three key requirements, the adsorption capacity, reversibility, and selectivity, to eventually work toward greener separation technologies.