Antifouling layers on membranes Development of conducting polymer layers on membranes to prevent biofouling and enhance biocide effects

Aims 

The aim of this project is to prevent and reduce biofouling on membranes and to remove any biofilms that have already formed. To achieve this, membranes are coated with conducting polymers e.g. polypyrrole, polythiophene or polyaniline and the polymer layer is polarised. This polarisation inhibits biofouling and enhances the effect of biocides.

The conducting polymer can be modified as cation- or anion-exchanger and its porosity can be controlled to avoid any impairment of the membrane by the polymer layer.

This new method of preventing biofouling offers economic and ecological benefits compared to conventional methods because it avoids or reduces the use of biocides and thus prolongs the operating time of the membranes.
This project is worked on in cooperation with the IWW in Mülheim / Ruhr

Results

A method and a cell for coating membranes have been developed and different membranes, such as cation- and anion-exchanger, ultrafiltration and reverse osmosis membranes, have been coated with polypyrrole (ppy). The coated membranes are investigated by scanning electron microscopy (SEM) and cyclic voltammetry. The ppy coatings can be depicted well by SEM and cyclic voltammograms show the electrochemical activity of the coated membrane.     

Surface angle investigations show that the ppy coating increases the hydrophilicity of the membranes.

The adhesion of microorganisms is tested on stainless steel samples as well as ppy-coated membranes in dependence on different polarisation potentials.

Das IGF-Vorhaben Nr. der Forschungsvereinigung DECHEMA e.V., Theodor-Heuss-Allee 25, 60486 Frankfurt am Main wurde über die AiF im Rahmen des Programms zur Förderung der industriellen Gemeinschaftsforschung (IGF) vom Bundesministerium für Wirtschaft und Energie aufgrund eines Beschlusses des Deutschen Bundestages gefördert.