Smart PDDA/PAA multilayer coatings with enhanced stimuli responsive self-healing and anti-corrosion ability

We report the design and fabrication of smart polydiallyldimethylammonium chloride (PDDA)/polyacrylic acid (PAA) multilayer coatings with enhanced stimuli responsive self-healing and anti-corrosion ability for 430 stainless steel (SS). The multilayer coatings were prepared by layer-by-layer (LBL) technique, which allows a fine control over layer numbers (n) and coating thickness. The dependence of anti-corrosion and self-healing properties on layer number was investigated in 3% NaCl solution. The involved self-healing is attributed to the stimuli responsive swelling and electrostatic repairing of the polyelectrolyte multilayers (PEMu) in the vicinity of the scratches. The enhanced corrosion resistance ability is mainly due to the multilayer structure and the self-healing behavior that lengthens and hinders the diffusion pathway of corrosive species. (C) 2015 Elsevier B.V. All rights reserved.