Regensburg 2025 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 31: Responsive and Adaptive Polymers
CPP 31.5: Talk
Wednesday, March 19, 2025, 17:30–17:45, H38
Acoustic levitation for dynamic studies of poly(N-isopropylacrylamide) microgels at the air-water interface — •Atieh Razavi1, Regine von Klitzing1, Romain Bordes2, and Amin Rahimzadeh1 — 1Soft Matter at Interfaces, Institute for condensed Matter Physics, Technical University of Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany — 2Applied Surface Chemistry, Chalmers University of Technology, Gothenburg, Sweden
Acoustic levitation provides a unique platform for studying the surface dynamics of an air-water interface covered with poly(N-isopropylacrylamide) (PNIPAM) microgels. By utilizing standing acoustic waves, droplets are trapped at nodal positions, creating a contact-free environment to examine the effects of microgel stiffness, droplet evaporation, and amplitude modulation on droplet deformation. The research focuses on quantifying the aspect ratio (AR) of levitated droplets as a function of frequency of amplitude modulation, microgel concentration, and cross-linker content over time. In addition, we modulate the amplitude of the acoustic pressure at different frequencies (0.005 Hz0 to 05 Hz) to get insight into the interfacial rheology. With this new method, we can qualitatively characterize the interfacial behavior of microgels at the air-water interface such as the elastic modulus of the interface and adsorption kinetics[1].
Keywords: Microgels; Acoustic levitation; elastic modulus; PNIPAM