Voltage in an Electro-Osmotic Cell

When either an externally applied voltage or a galvanically created voltage is applied to an electro-osmotic cell, a number of potential drops develop within the cell which together constitute the total voltage. A simple extension of Eq. (20) will give the components of the voltage V, as follows  

On comparison with Eq. (20), which defines various quantities at open circuit (i.e., in the absence of the passage of an externally applied current, although short-circuiting on open circuit will cause the flow of some current owing to the fuel-cell type of effects discussed earlier), it 

In a more detailed analysis, one must decompose for water 

It is thus clear that in most of the empirical studies on EOD, one talks of voltage across the cell or some variation thereof (e.g., field, i.e., voltage divided by the length of the clay column in the cell) as if it were a single quantity. It is, in fact, a quite complex quantity constituted of several components [see Eq. (31)] and this should be taken into account, as far as possible, in interpreting the results from EOD experiments. 

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