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Diffusion Reaction Interaction for a Pair of Spheres - ETD ...

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problems focused on diffusion to two competing particles where the concentration<br />

infinitely far from the two spheres is fixed. Samson and Deutch (1977), Zoia and<br />

Strieder, (1998) and Strieder and Saddawi (2000) all use the bispherical<br />

coordinate system to resolve the impenetrable sink-sink problem. Samson and<br />

Deutch (1977) presented the exact solution <strong>for</strong> the concentration pr<strong>of</strong>iles <strong>of</strong> two<br />

equal sized (monodispersed) spherical sinks with infinitely fast surface reactions<br />

(diffusion control). Zoia and Strieder (1998) extended the work <strong>of</strong> Samson and<br />

Deutch (1977) by producing exact, asymptotic solutions <strong>of</strong> the sink-sink surface<br />

reaction problem <strong>for</strong> two identical sinks with the same first order reaction rate<br />

constant at the surface <strong>of</strong> both spheres. Their work included the development <strong>of</strong><br />

the reaction rate as an asymptotic expansion in the dimensionless inverse reaction<br />

rate <strong>for</strong> the diffusion to reaction-controlled cases. Strieder and Saddawi (2000)<br />

provided an alternate solution <strong>for</strong> two monodispersed spheres with a first order<br />

reaction occurring at the surface <strong>of</strong> the spheres. These authors used an iterative<br />

technique to generate an exact; convergent series expression <strong>for</strong> the reaction rate<br />

<strong>of</strong> the two spheres.<br />

Tsao (2001) used the method <strong>of</strong> twin spherical expansion (Ross, 1968 and<br />

1970) to solve the competitive diffusion-reaction problem <strong>for</strong> diffusion-limited to<br />

reaction-limited conditions <strong>for</strong> two penetrable sinks and two impenetrable sinks.<br />

His series expansion solution <strong>for</strong> the reaction rate <strong>for</strong> two impenetrable spheres <strong>of</strong><br />

equal size was compared with the series solution <strong>for</strong> two permeable spheres <strong>of</strong><br />

equal size. These rates are expressed in terms <strong>of</strong> the center-to-center distance. In<br />

4

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