Permselective Collodion Matrix Membranes

Collodion is a mixture of pyroxylin in alcohol and ether. It represents an incomplete nitration of cellulose. Collodion matrix membranes can support high anionic or cationic charge densities and therefore can be made highly selective. Electrical resistance can be adjusted over several orders of 

TABLE 6.1. Concentration Potentials (mV) across Permselective Membranes for 2 1 Concentration Ratios of KCI Solutions at 25° C  

TABLE 6.2. Dependence of Concentration Potentials (mV) upon Concentration for 2 1 Ratios of KCI Solutions across Typical Permselective Protamine Collodion Matrix Membranes for Two Extrema of Membrane Resistance at 25°C  

Membranes using a matrix of materials other than collodion have also been prepared. Heterogeneous membranes are prepared by imbedding particles of ion-exchange resins in an inert binder, which serves as a frame to support the resin between the solutions. 

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