Noise of the Synthetic Membrane-Electrolyte Interface

We present in this section some interesting results concerning the membrane-electrolyte interface properties in the case of a collodion membrane.The membranes are collodion thick films (sslO m) made from a 4% collodion solution in diethylether these membranes contain fixed negative electrical charges inside. The electrolyte on both sides of the membrane is aqueous NaCl (concentration 2 x 10 -0.1 mol/liter), the active membrane surface is 1.2 cm, and the electrodes are made of platinized platinum. The power spectrum corresponding to the noise emitted by the total system is 

With the Brophy and Webb method it is possible to obtain by noise measurements the R and C values separately. 

FIGURE 4. Schwan s model, (a) Complete model, (b) Device seen by the noise spectrograph. 

This model was generalized in the following way In a first step 

FIGURE 5. Variation of noise resistance Rc and noise capacitance of the cell measurement versus the frequency v. The concentration of the electrolyte (NaCl) inside the cell is 5 X 10 mol/liter. , R in presence of membrane O, in presence of membrane , Rc without membrane , without membrane. 

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