3 research outputs found
Experimental Investigation of the Self-Propelled Motion of a Sodium Oleate Tablet and Boat at an Oil–Water Interface
The self-propelled behaviors of macroscopic
inanimate objects at
surfaces and interfaces are ubiquitous phenomena of fundamental interest
in interface science. However, given the existence of a large variety
of systems with their own inherent chemical properties, the kinematics
of the self-propelled motion and the dynamics of the forces driving
these systems often remain largely unknown. Here, we experimentally
investigate the spontaneous motion of a sodium oleate tablet at a
water–nitrobenzene interface, under nonequilibrium and global
isothermal conditions, through measurements of the interfacial tension
with the noninvasive, quasi-elastic laser scattering method. The sodium
oleate tablet was self-propelled due to an imbalance in the interfacial
tension induced by the inhomogeneous adsorption of oleate/oleic acid
molecules. The kinetics of the self-propelled motion of a boat-shaped
plastic sheet bearing sodium oleate tablets at a sodium oleate aqueous
solution–nitrobenzene interface was also studied. The interfacial
tension difference between the front and rear of the boat was quantitatively
identified as the force pushing the boat forward, although the Marangoni
flow due to the uneven distribution of the interfacial tension behind
the boat tended to decelerate the motion
Experimental Investigation of the Self-Propelled Motion of a Sodium Oleate Tablet and Boat at an Oil–Water Interface
The self-propelled behaviors of macroscopic
inanimate objects at
surfaces and interfaces are ubiquitous phenomena of fundamental interest
in interface science. However, given the existence of a large variety
of systems with their own inherent chemical properties, the kinematics
of the self-propelled motion and the dynamics of the forces driving
these systems often remain largely unknown. Here, we experimentally
investigate the spontaneous motion of a sodium oleate tablet at a
water–nitrobenzene interface, under nonequilibrium and global
isothermal conditions, through measurements of the interfacial tension
with the noninvasive, quasi-elastic laser scattering method. The sodium
oleate tablet was self-propelled due to an imbalance in the interfacial
tension induced by the inhomogeneous adsorption of oleate/oleic acid
molecules. The kinetics of the self-propelled motion of a boat-shaped
plastic sheet bearing sodium oleate tablets at a sodium oleate aqueous
solution–nitrobenzene interface was also studied. The interfacial
tension difference between the front and rear of the boat was quantitatively
identified as the force pushing the boat forward, although the Marangoni
flow due to the uneven distribution of the interfacial tension behind
the boat tended to decelerate the motion
Giant Vesicles Containing Superparamagnetic Iron Oxide as Biodegradable Cell-Tracking MRI Probes
A major breakthrough in <i>in vivo</i> cellular
imaging
has been the clinical/preclinical use of magnetic resonance imaging
(MRI) with contrast agent. Superparamagnetic iron oxide (SPIO) is
a promising candidate for the development of smart MRI probes for
cell-tracking. In the present study, we describe biodegradable probes
made of giant vesicles (GVs; closed lipid membranes with diameters
>1 ÎĽm) that encapsulate SPIO for use as an MRI contrast agent.
These SPIO-containing GVs (SPIO-GVs) exhibited excellent contrast
enhancement in the single cell of medaka fish (<i>Oryzias latipes</i>) embryos immediately after their microinjection, and this enhancement
disappeared when the GV membranes were destroyed. Our results demonstrate
that SPIO-GVs are useful MRI probes for single cell-tracking that
have minimum cytotoxicity and will greatly improve clinical/preclinical <i>in vivo</i> cellular imaging techniques