Anodic Coating of 1.4622 Stainless Steel with Polydopamine by Repetitive Cyclic Voltammetry and Galvanostatic Deposition

Abstract

Polydopamine exhibits high potential as coating of materials used for medical devices, antifouling, and corrosion prevention. Repetitive cyclic voltammetry on gold electrodes was used to deposit polydopamine by anodic oxidation. Investigation of polydopamine formation in the pH range 5–8 showed that coating at pH 6.5 permits selective polydopamine formation on the electrode, while auto-oxidation of dopamine in the electrolyte could be suppressed. The optimized conditions then were transferred to stainless steel electrodes. At pH 6.5–6.6, an anodic peak current density of 12.9 μA/mm2 was measured using a plane stainless steel anode in 5 mM dopamine solution. During experimental scale-up, anodic coating of 1.4622 steel plates in galvanostatic experiments led to formation of a colored polydopamine surface, which exhibited reduction of the water contact angle by 13.5°. The controlled anodic polydopamine formation is of a particular value for an economic polydopamine coating of the conductive material in larger-scale applications.

Physicochemical and Electrochemical Characterization of Electropolymerized Polydopamine Films: Influence of the Deposition Process

“…Predominantely, cyclic voltammetry (CV) in oxygen-free basic dopamine solution is employed to deposit PDA [ 13 ]. Other electrochemical methods, such as galvanostatic deposition [ 14 ] and pulsed deposition [ 15 , 16 , 17 ], have been described in the literature. Although electrochemical PDA deposition is limited to (semi)conductive substrates, the electrochemical route allows fast deposition times in the range of seconds, in contrast to dip coating, which usually takes several hours to form PDA.…”

Redox Switchable Polydopamine-Modified AFM-SECM Probes: A Probe for Electrochemical Force Spectroscopy

“…To date, most PDA coatings are obtained by dip coating, as PDA films can be formed on almost any kind of surface, ranging from inorganic to organic materials including noble metals, oxides, and polymers. Apart from auto-oxidation, PDA films can also be obtained via electrochemical deposition by cyclic voltammetry, , galvanostatic, or by pulsed deposition, which was demonstrated in direct mode scanning electrochemical microscopy (SECM) . Electrochemical deposition results in uniform films with increased film thickness compared to films obtained via dip coating.…”

Improving the Anticorrosion and Self-Healing Properties of the Epoxy Coating Using the Mn–Zn2SiO4/PDA Composite

“…27,28 Additionally, PDA exhibits an abundance of planar conjugated structures and donor−acceptor configurations, which contribute to its broad absorption spectra and excellent electrochemical properties. 29,30 The remarkable adaptability, strong adhesion to substrates, environmentally friendly degradation, and self-healing capabilities make PDA a promising material for corrosion-resistant modification. Li et al 31 applied a PDA anticorrosion coating on the surface of N80 steel through PDA self-polymerization and assembly.…”

“…PDA is a bioinspired material that draws inspiration from mussel adhesive proteins. − The structure contains catechol and primary amine groups, , which impart it excellent adhesion to metal substrates, , metal coordination, , and antioxidant capabilities. , The abundant modifiable sites in its structure enable PDA to undergo chelation with metals, making it suitable for the modification of various functional materials. , Additionally, PDA exhibits an abundance of planar conjugated structures and donor–acceptor configurations, which contribute to its broad absorption spectra and excellent electrochemical properties. , The remarkable adaptability, strong adhesion to substrates, environmentally friendly degradation, and self-healing capabilities make PDA a promising material for corrosion-resistant modification. Li et al applied a PDA anticorrosion coating on the surface of N80 steel through PDA self-polymerization and assembly.…”