Colorful poly(dopamine) coated aluminum pigments, their corrosion resistance and color performance

Colorful aluminum pigments are commercial demand for the pursuit of a range of aesthetic over the last few years. In this study, a general approach for preparation of colored aluminum pigments is reported by two-step process of poly(dopamine) (PDA) encapsulation and dye conjugation. Firstly, the surface of the aluminum pigment was encapsulated by a PDA layer in an alkaline/ethanol environment (PDA@Al), and orthogonal experiments were investigated to explore the optimal reaction conditions. Secondly, using Disperse orange 11 as typical dye, the PDA@Al were colored by the Michael addition reaction between the functional dyes and quinone structures in the PDA layer. The morphology, component and structure of the colored aluminum pigments was characterized by FTIR, SEM , XPS and TG. The results showed that the corrosion resistance and wettability of colored aluminum pigments were significantly improved. This wok provides a new general strategy for the preparation of colorful aluminum pigments with PDA as the protected and functional layer.