Role of Adhesion in Electrochemical Impedance Spectroscopy

Electrochemical impedance spectroscopy (EIS) is a valuable method with which to study the barrier property and corrosion protection performance of polymer-coated metals it has been widely used in this field in recent years [11-15]. Many examples can be found in the literature, which illustrate the performance deterioration of different coatings on metals as well as pretreatment effects on the properties of 

The overall corrosion protection of a metal, as well as general protective coatings irrespective of their function of coating, depends on the performance of a system as a whole, including its many interfaces and coating layers. These factors are not only mutually dependent as a combination but also in the order of application (permutation). Any single factor cannot be treated as a dominant one. There is very little work in the literature that focuses on the role of interfacial factors in the corrosion protection performance of coated systems. 

An ideal model system was selected to study the interfacial factors with EIS [19]. The model system was Parylene C-coated Alclad (aluminum-clad aluminum alloy). In this system, the surface state of the top surface (salt solution/coating interface) and the adhesion of the coating (coating/metal interface) were modified to study the influence of these factors on the corrosion protection performance of the system. 

Parylene C film does not adhere well to any smooth surface due to its unique polymerization mechanisms as described in Chapter 5. A freestanding film can be easily peeled off of the substrate surface, although a film does not peel off by itself in many cases, even if immersed in water. This feature enables us to investigate a system 

Combination of Interfaciai Factors for Each Sampie Studied 

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