(322b) Vertically-Oriented-Capillary Video-Microscopy: Drops Levitated by a (Reacting) Fluid
AIChE Annual Meeting
Tuesday, October 18, 2011 - 12:55pm to 1:15pm
Microscopy in a vertical capillary provides the ability to continuously observe dynamic particle phenomena on microscopic objects levitated by an imposed flow. Such a technique was developed and used to monitor levitated droplets, by manually regulating the imposed flow so as to keep the droplets suspended in the area of view. Local sudden increases and decreases in temperature were achieved with an external heating filament, which produced rapid changes in the fluids’ properties (viscosity and density). Even in such cases it was possible to control the immersed drop’s position in the microscope’s field of vision by adjusting the immersing fluid’s vertical flow. The shrinkage and alteration of acid drops that react with the basic nanoparticles of an immersing flowing oil, verified that fluid flow accelerated significantly the neutralization of the levitated acid drop by the basic nanoparticles of the suspending medium, when compared to flowless conditions. Allowing droplets to be kept suspended in high-temperature regions and to rotate at fixed positions, this technique may be used as an improved way to mix contents in suspended microscopic droplets.