Magnetophoretic Evaluation of Interfacial Adsorption of Dysprosium(III) on a Single Microdroplet

Abstract

Magnetophoretic velocimetry is a novel technique to measure the magnetic susceptibility of a single microparticle. This techinique could be applied to study the interfacial adsorption equilibria of a paramagnetic dysprosium(III) ion with capric, lauric or stearic acid for a single 2-fluorotoluene microdroplet. The observed magnetic susceptibility of the microorganic droplets was reciprocally proportional to its radius in each case. From the proportional constant, the interfacial concentration of Dy(III) was determined. Furthermore, the dependences of the interfacial concentration on the initial Dy(III) concentration and pH were examined in order to analyze the adsorption equilibrium. Finally, the saturated interfacial concentration and the interfacial adsorption constant at the infinite dilution of Dy(III)-laurate complex were evaluated as 4.8 × 10 -10 mol cm -2 and 3.4 × 10 -2 dm, respectively.

Particle Manipulation with External Field; From Recent Advancement to Perspectives

“…The magnetophoretic velocity of the droplet became larger due to the interfacial complexation of Dy(III), which changed χp. 68 Whitesides et al developed a novel magnetic manipulation, called magnetic levitation (MagLev). [69][70][71][72][73] MagLev can recognize the density of a particle or a liquid droplet and levitate it at the coordinate, where the magnetic and sedimentation forces are balanced (Fig.…”

Zero-velocity Magnetophoretic Method for the Determination of Particle Magnetic Susceptibility

“…1 The magnetophoresis separation of various particles has been studied, which included paramagnetic particles of biological cells bound with magnetic particles, [2][3][4][5][6][7][8][9][10] as well as diamagnetic particles of nucleic acids and proteins, 11 single emulsion droplets, 12 single red blood cell, 13 a dysprosium(III) adsorbed organic droplet, 14,15 a single crystal of Prussian blue analogue, 16 polystyrene particles, 17 polymer beads, 18 bacillus atrophaeus spores, 19 and allergen-specific immunoglobulin E. 20 However, studies on magnetophoretic velocity analysis, which is sometimes called magnetophoretic velocimetry, to determine the particle magnetic susceptibility are still limited. The one-dimensional horizontal-migration magnetophoretic velocity, v, of a spherical particle in a liquid medium, when the density of the particle is not so far from that of the medium, hence the magnetic force, the magnetic buoyancy, and the viscous force on the particle are balanced, is expressed by the next equation: …”

Brownian motion-magnetophoresis of nano/micro-particles

“…Previously, the increase of magnetic susceptibility of organic droplets in a paramagnetic ion solution was analyzed in terms of an interfacial magnetic susceptibility, which was increased by the interfacial adsorption of the paramagnetic ion. 25,26 Fuh and Chen found the change of the particle magnetic susceptibility by the adsorption of paramagnetic ions on its surface. 27 The interfacial magnetic susceptibility is thought to be a new parameter to evaluate the surface activity of the particle surfaces.…”