Regensburg 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 32: Poster Session II

CPP 32.10: Poster

Thursday, March 20, 2025, 09:30–12:00, P3

Molecular Imprinting of PEDOT in Polyelectrolyte Multilayers — •Martin Hunger, Muhammad Khurram, Sven Neuber, and Christiane A. Helm — martin.hunger@uni-greifswald.de

Electrically conductive films of Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid) (PEDOT:PSS) are formed by sequential adsorption of oppositely charged macromolecules. PEDOT:PSS serves as polyanion, and PDADMA is the polycation. When the top layer is PEDOT:PSS, the electrical conductivity is large (8 kS/m), when the top layer is PDADMA, the electrical conductivity is three orders of magnitude lower. In addition, vis-IR absorption spectroscopy shows that the PEDOT density in PEDOT:PSS-terminated films is high, while it is low in PDADMA-terminated films. When a PDADMA layer is adsorbed, turbidity measurements of the adsorption solution show that PEDOT diffuses out of the film. This can be explained entropically: a few PDADMA molecules with many positive charges replace many small molecules with few positive charges. Furthermore, exposure to solutions with divalent or trivalent cations reduce the conductivity of PEDOT-PSS-terminated films. We discuss whether PSS returns to previous binding sites upon adsorption of PEDOT:PSS, a behaviour that is typical for molecular imprinting.

Keywords: PEDOT:PSS; Conductive coating; Polyelectrolyte multilayer; Layer-by-Layer coating; Molecular Imprinting