Deposition, surface, dynamic processes

Once the initial layer of PPy is deposited, it becomes a reactant that determines the course of the remainder of the polymerization process. Polymerization occurs more readily (at a lower potential) on the already-deposited PPy than on the anode surface. This process of product becoming reactant continues until the reaction is stopped. A more detailed investigation of the polymerization process reveals the intricacies involved in producing these sophisticated dynamic structures. Thus, the overall process may be broken into several discrete steps, as shown in Figure 2.1 (details are available in Reference 4). 

You may be surprised, but fouling is not always detrimental. The term dynamic membrane describes deposits that benefit the separation process by reducing the membrane s effective MWCO Molecular Weight cut-off) so that a solute of interest is better retained. Concentration polarization refers to the reversible build-up of solutes near the membrane surface. Concentration polarization can lead to irreversible fouling by altering interactions between the solvent, solutes and membrane. 

---