Spray‐On Polymer–Clay Multilayers as a Superior Anticorrosion Metal Pretreatment
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© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Pretreatment coatings applied to metals are essential in the overall performance of anticorrosion coating systems. Hexavalent chromium, a widely used pretreatment for aluminum is now considered harmful. Therefore, a need for environment-friendly yet efficient and scalable pretreatment coatings has emerged. Here, the authors present the spray-assisted layer-by-layer (LbL) assembly and anticorrosion performance of a highly ordered polymer–clay nanocomposite coating. This approach is an entirely water-based process, allowing for application over large surface areas. This novel pretreatment coating (25 wt% clay) presents a brick-and-mortar multilayered structure, where the montmorillonite clay (MMT) acts as a physical oxygen barrier, while preventing the dissolution of corrosion products—thus delaying corrosion. The branched polyethylenimine polymer (BPEI) mortar provides surface buffering once the corrosion process initiates. The anticorrosion properties of the LbL coating are evaluated using electrochemical measurements and salt-spray testing. This BPEI/MMT system presents good anticorrosion properties, making it a potential alternative pretreatment. (Figure presented.).
author list (cited authors)
Suarez‐Martinez, P. C., Robinson, J., An, H., Nahas, R. C., Cinoman, D., & Lutkenhaus, J. L.