Electrets are materials able to store electrical charges for a long period of time. Such charge storage media can be used as microphones, transducers or as filter media. The research activities at the department deal with the development and characterization of new polymeric electret materials from different polymer blends/or additives. For this purpose, electrets, with exceptional charge stability, based on polypropylene (PP), polyetherimide (PEI), polyphenylene ether (PPE) and its blends are developed. The materials are electrically charged using corona-charging (in the case of films and foams) or electrospinning (in the case of fibers) and the stability of such charges is evaluated as function of time and/or temperature. The charge storage properties can be improved by using additives and/or by the modification and tailoring the morphology. Porous polymers with high anisotropy (see the picture) show a significant improvement of the electret properties, as the pores act as spatial barriers to the charge carrier migration.


Contact: M.Sc. Merve Demir
Phone: +49(0)921 55 74 60
Fax: +49(0)921 55 74 73
Email: merve.demir@uni-bayreuth.de



Polymer electrets

Improving electret properties by tailoring the polymer foam morphology