Projects per year
Ferrofluids are magnetic liquids known for the patterns they form in external magnetic fields. Typically, the patterns form at the interface between a ferrofluid and another immiscible non-magnetic fluid with a large interfacial tension γ ∼ 10−2 N m−1, leading to large pattern periodicities. Here we show that it is possible to reduce the interfacial tension several orders of magnitude down to ca. γ ∼ 10−6 N m−1 by using two immiscible aqueous phases based on spontaneous phase separation of dextran and polyethylene glycol and the asymmetric partitioning of superparamagnetic maghemite nanoparticles into the dextran-rich phase. The system exhibits classic Rosensweig instability in a uniform magnetic field with a periodicity of ∼200 μm, significantly lower than in traditional systems (∼10 mm). This system paves the way towards the science of pattern formation at the limit of vanishing interfacial tension and ferrofluid applications driven by small external magnetic fields.
FingerprintDive into the research topics of 'Ferrofluidic aqueous two-phase system with ultralow interfacial tension and micro-pattern formation'. Together they form a unique fingerprint.
-: Controlling and Probing Dynamics, Phase Transitions and Collective Behavior of Active Matter with Magnetic Tweezers
01/09/2018 → 31/08/2023
Project: Academy of Finland: Other research funding