Fig. 5: Interfacial normal-field instability of a FF-ATPS in a horizontal glass capillary.
From: Ferrofluidic aqueous two-phase system with ultralow interfacial tension and micro-pattern formation
a Scheme of glass capillary geometry, and front view scheme of a FF-ATPS sample in a capillary, showing the direction of the magnetic field and gravity in relation to the interface between light and dense phases. b Images of the view along the z-axis in function of the magnetic field applied (first row), zoom of the central area of the images (second row), and scheme of the proposed shape of the interface between the two phases for a section along the x–z plane. c processed \(-\ln ({{{{{{{{\rm{I/I}}}}}}}}}_{0})\) image detail of the pattern. The two red arrows represent the two main directions in the unit cell of the pattern lattice. d 3-dimensional reconstruction of the pattern shape. e Plot of the \(-\ln ({{{{{{{{\rm{I/I}}}}}}}}}_{0})\) values calculated along the a1 + a2 direction for three different magnetic fields (yellow squares for B = 0.0 mT, red circles for B = 5.2 mT and purple triangles for B = 6.4 mT). f Plot of the pattern periodicity as a function of the magnetic field applied for three different samples (red squares for Sample 0, blue circles for Sample 1, and black triangles for Sample 2). The full lines represent linear interpolation of the data. g Plot of the pattern amplitude as a function of the magnetic field applied for three different samples (same colors and shape coding of panel f).
