Berlin 2024 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 15: Poster I

CPP 15.9: Poster

Monday, March 18, 2024, 18:00–20:00, Poster C

Influence of single particle softness on the elasticity of microgel covered interfaces — •Carina Schneider, Sebastian Stock, Joanne Zimmer, and Regine von Klitzing — Department of Physics, TU Darmstadt, Hochschulstraße 8, 64289 Darmstadt

Softness strongly influences the behavior of microgels (MG) adsorbed at liquid interfaces. Therefore, it is fundamental to understand and quantify its effect via the microscopic scale on the macroscopic layer. For this purpose, we spread homogeneous and heterogeneous poly-NIPAM MGs at the air-water interface of a Langmuir trough, and determine the compression isotherms. This enables the calculation of the compression dependent elasticity. We control the stiffness of the MG particles by varying the cross-linker density. To artificially increase the stiffness of the single particles we add latex particles to the system. Simultaneously, we observe the lateral structure formation, by transferring and subsequently scanning the particle layer on a Silicon wafer using atomic force microscopy. The elasticity of the particle layer at the interface exhibits a maximum as a function of the surface pressure. Counterintuitively, the maximum value increases with decreasing stiffness of the particles.

Keywords: Microgels; Elasticity; Interfaces; Softness; Compression