Electrophoretic deposition double-layers

Electrophoretic deposition is used extensively in the automobile industry to form undercoats on car bodies and in many other applications. The successful application of electrophoretic deposition relies on choosing the correct environment, particle size, and system chemistry to achieve coatings of the desired properties. Of critical importance is the ability to determine and control surface charge and the structure of the electrical double layer. 

Fig. 11 Diagram of the electrophoretic expression rolls extmder Elephant , 1979 1. outlet of excess slip to be recycled, 2. deposit being formed by electrophoresis, 3. counter electrode (cathode), 4. inlet of the slip, 5. zinc anode, 6. double-layer band of ceramic body, 7. band...

It can be concluded from the above-mentioned differential capacitance curve and cathodic polarization curve analyses that the mechanistic model of electrolytic codeposition of Hquid microcapsules is associated with the stable chelation of—OH and -O groups of the wall material (e.g., PVA, gelatin) with metal ions (e.g., Ni ", Cu +), and this gives rise to positively charged microcapsules. This in turn helps to accelerate the electrophoretic migration of microcapsules in the plating solution. The liquid microcapsules were also adsorbed onto the electrode due to the presence of a surfactant. Consequently, it is feasible for microcapsules to enter the electrical double layer at the interface and to become embedded in the co-deposited coating. 

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