Gelatin electrolytic separation

Consider two compartments, occupying the regions — 1 < x < 0 and 0 < x < 1, respectively, filled with solutions of the same univalent electrolyte at concentrations 1 and A, respectively. Let at some moment t — 0 the wall separating the compartments at x = 0 be removed. The solution within the compartments is assumed immobilized, say, with gelatin, so that the entire transport is due to electro-diffusion only. The initial values of the electrolyte concentration are maintained at the external walls x = 1. These walls are electrically insulated so that no electric current can pass through them. 

Fig. 291 which represents an electrol5d ic cell divided into three compartments, illustrates the use of these membranes. Cations cannot escape from the anode compartment because they cannot penetrate the anion exchange membrane A both cations and anions can leave the centre compartment, but anions cannot pass from the cathode compartment. Thus the liquid in the centre compartment is demineralised. A process for separating electrolytes from non-electrolytes such as glycerol, sucrose or gelatin is based on this idea. 

With the use of sohd to gelatinous, polymeric electrolyte layers that ensure electrical separation of the electrodes and the unity of the cell components combined with good conductivity for lithium ions, it is not necessary to employ hquid electrolytes in lithium batteries. This simplifies the production of lithium polymer batteries, which are also safer in operation because the electrolyte is polymeric, not liquid. This battery cell structure facilitates production of thin foil batteries, a favorable form for use in portable devices. The expected performance data correspond to what is obtained with other lithium ion systems. 

Colloidal dispersions of proteins, such as a gelatin, can often be caused to separate into two layers by addition of a solution of an electrolyte. Given that protein molecules may carry electrical charges on their outer surface as illustrated in Figure 13.30, what do you believe happens when the electrolyte solution is added ... 

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