Regensburg 2019 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 12: Poster II

BP 12.39: Poster

Dienstag, 2. April 2019, 14:00–16:00, Poster B2

The impact of antifoam agents on lipid membranes at the air-water-interface — •Mike Moron, Michael Paulus, Julia Nase, Susanne Dogan, and Metin Tolan — Fakultät Physik/DELTA, TU Dortmund, 44221 Dortmund, Germany

The control of foam by means of antifoam agents is of great importance in a number of industrial and medical applications. For example, the oral medication of simethicone is prescribed in the case of surfactant intoxication and also in order to dispose patients for coloscopy. While the macroscopic behavior of liquid systems containing antifoam agents and lipids is well described, the behavior of antifoam agents on the molecular scale is not completely understood.

We present surface pressure-dependent in-situ X-ray reflectometry (XRR) experiments and a Brewster-angle microscopy (BAM) study on Langmuir monolayers consisting of different lipids and antifoam agents. Both, the XRR and BAM measurements were performed at the liquid-air interface.

A stearic acid monolayer served as a model for a foam lamella and the impact of an industrial used antifoam agent was analysed. Furthermore, a dipalmitoylphosphatidylcholine (DPPC) monolayer was prepared to mimic a cell membrane and the impact of the medical antifoam agent simethicone was studied. The measurements showed a strong effect on the lipid layers structure for low surface pressures of the lipid films. For high surface pressures the antifoam agents had little to nearly no effect on the lipid films.