Berlin 2024 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 15: Poster I
CPP 15.10: Poster
Monday, March 18, 2024, 18:00–20:00, Poster C
How Ultrasound Accelerates Microgel Adsorption Kinetics at Liquid Interfaces — •Luca Mirau1, Sebastian Stock1, Amin Rahimzadeh1, Sonja Wismath2, Matthias Rutsch2, Mario Kupnik2, and Regine von Klitzing1 — 1Soft Matter at Interfaces, Institute for Condensed Matter Physics, TU Darmstadt, Hochschulstraße 8, 64289 Darmstadt — 2Measurement and Sensor Technology, TU Darmstadt, Merckstraße 25, 64283 Darmstadt
Poly-N-isopropylacrylamide (PNIPAM) based microgels (MGs) are surface-active and offer great opportunities as stabilizers of emulsions and foams. Due to their thermosensitive response the MGs enable also destabilization on demand. However, emulsion formation implies energy input by stirring or ultrasonication. To understand this formation process, it is important to understand the interfacial adsorption of the MGs. A fast trigger to affect the adsorption process is given by ultrasonication. The present study shows the effect of ultrasound on the adsorption kinetics of PNIPAM MGs at the water-oil interface monitored by drop shape tensiometry. The adsorption kinetics of MGs accelerates with increasing ultrasonication intensity. The variation of different parameters, such as ultrasonic frequency, MG crosslinker density, concentration, phase composition and temperature, indicates that both acoustic streaming as well as ultrasound induced deswelling of MGs due to breakage of hydrogen bonding cause this acceleration.
Keywords: Microgels; Ultrasound; Adsorption Kinetics