Suspended-drop

One or more sparingly soluble monomers are charged to the reactor to form suspended drops. The monomer quickly saturates the aqueous phase. 

Mass transfer of monomer from the suspended drops through the aqueous phase to the seeded particles continues throughout the polymerization. 

The suspended drops of monomer are eventually depleted and polymerization stops. 

These three equations can be solved simultaneously (by iteration) for rx/R, r2/R, and r-JR. It is assumed that the size of the suspended drops is known as well as the density and viscosity of the liquids and the overall dimensions and speed of the centrifuge. 

Various equilibrium forms of suspended drops can be obtained for different values of the radius of curvature at the drop tip and for different values of surface tension and gravitational forces, as calculated by Tanasawa and Toyoda.[41] These researchers also... 

Figure 4.9 Two modes of liquid phase microextraction, (a) Suspended drop method and (b) membrane loop method.

Bolt, Boyle, and Mirsky (2E) discuss and evaluate different techniques of producing droplets. Their work includes photographing drops falling through a vertical furnace. They have successfully suspended drops in a vertical wind tunnel, using a stationary ultrasonic field to center the drop. 

A large portion of the literature discusses the use of suspended drops on fine filaments. This technique has been used with visual and photographic observation (5E, 6Ef 8E, 9E, llEt 16E). Results show the mass rate of change of size due to evaporation to be proportional to the first power of the diameter. Kobayasi (HE, 15E) first suspends the droplet on a silica filament and then moves a heated furnace to surround the droplet. Nishiwaki (19E) uses a similar experimental device. Instead of a filament to support the drop, Wakil, Uyehara, and Myers (25E) use a fine thermocouple. 

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