Most-Studied Candidates and Coating Methodology

The most studied candidate CP to date remains P(ANi), although P(Py) has also been well studied. Wrobleski et al. [617, 942] have studied a number of poly(3-alkyl thiophenes) and poly(3-thienylene acetates). Chandrasekhar et al. [934] have studied a number of poly(aromatic amines), such as derivatives of poly(diphenyl amine). 

CP coatings have generally been applied in two ways 1) As neat CP coatings per se, which are subsequently topcoated with epoxies or other resins for physical durability (i.e. a two-component system is used). 2) As blends with epoxy or other binders (i.e. in a one-component systems). 

Neat CP coatings have generally been put down from solutions of de-doped CP (in solvents such as l-Me-2-pyrrolidinone (NMP)), since doped CPs are mostly insoluble. These undoped coatings are then chemically doped via immersion in concentrated dopant solution, or, occasionally, electrochemically. Some doped CP coatings have been put down as sols (colloidal suspensions) [934] or as partial solutions [936]. 

One-component coatings generally involve preparing a blend or suspension of the CP, usually in its doped form, with the resin or polymer used as the binder (e.g. an epoxy or an adhesive). The blend is then directly coated on the metal. Coatings have been applied by standard methods, including dip-, spray- and brush-coating. 

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