Electron transfer partitioning technique

Partitioning technique in electron transfer and excitation energy transfer... 

Partitioning Technique in Electron Transfer and Excitation Energy Transfer 11... 

A physical model for film transport that accommodates the available experimental observations is a conventional film permeation model [10]. Candidate permeant molecules partition into a film from solution via an equilibrium process and then diffuse through the film to the electrode surface where they undergo oxidation or reduction. The redox product molecules then diffuse to the film/solution boundary and exit the film via a reverse partitioning step that, again, is sufficiently rapid to occur at equilibrium. Faradaic electrochemical techniques are especially powerful for interrogating such processes - in part because they require permeants to traverse films essentially completely in order for signals to be observed. (Recall that interfacial electron transfer can occur with reasonable efficiency only over distances of ca 10, or perhaps 20, A. Depending on the compound, these distances correspond to one or two film monolayers.)... 

Purpose. This exercise illustrates the general procedures that are used to determine a partition coefficient at the microscale level. Experience in weighing milligram quantities of materials on an electronic balance, the use of automatic delivery pipets for accurately dispensing microUter quantities of liquids, the transfer of microHter volumes of solutions with the Pasteur filter pipet, and the use of a Vortex mixer, are techniques encountered in this experiment. 

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