Deformation and necking of liquid droplets in a magnetic field

Pendant droplets of water and paramagnetic solutions are studied in the presence uniform nonuniform magnetic fields produced by small permanent magnet arrays, both static conditions during dynamic pinch-off. Static measurements droplet shape analysed terms an apparent surface tension {\gamma}app or effective density \r{ho}eff. The change deionized a field 450 mT is insignificant, 0.19 - 0.21 mNm-1. Measurements on compensated zero-susceptibility Cu2+, Mn2+ Dy3+ where unaffected any body force show changes about -1% 500 mT. Magnetic gradients up to 100 T2m-1 deform lead \r{ho}eff that negative for diamagnetic (buoyancy effect) positive solutions. profile strongly-paramagnetic 0.1 Dy M DyCl3 solution analysed, treating vertical gradient as spatial variation gravity. influence Maxwell stress discussed. In measurements, at pinch-off recorded high-speed photography relative field. surface-tension-dependent pre-factor scaling law governs dynamics shows no difference pure 0.11 has region because filament diameter much less than capillary length.