Oxidation-Mediated, Zwitterionic Polydopamine Coatings for Marine Antifouling Applications

Abstract

We synthesized a zwitterionic dopamine derivative (ZW-DOPA) containing both catechol and amine groups, and we demonstrated an excellent marine antifouling surface by controlling the oxidation of ZW-DOPA. The oxidation was mediated by the deprotonation of catechol or the addition of an oxidant (ammonium persulfate (AP) or sodium periodate (NaIO4)). The oxidation and subsequent molecular transformation of ZW-DOPA was investigated over time by UV–vis spectroscopy. Among the different oxidation conditions tested, NaIO4-induced ZW-DOPA coating was the most efficient and successfully formed on various substrates, such as titanium dioxide, stainless steel, and nylon. Compared with uncoated substrates, ZW-DOPA-coated substrates showed high resistance to marine diatom adhesion. Considering the ease of use and substrate independence of the ZW-DOPA coating, this method shows promise as a basis for inhibiting marine fouling on a variety of substrates used in the marine industry and aquatic environments.

Chemistry of Polydopamine – Scope, Variation, and Limitation

“…[102a] A disulfide containing ester of dopa was used to obtain a polymer by air oxidation, which is cleavable by reduction (Scheme ). [102b] Short interaction of sodium periodate with some side‐chain substituted dopamines was reported to stop at orange colored quinone monomers without providing comprehensive spectroscopic evidence except UV‐spectroscopy (Scheme ). Their rearrangement to 5,6‐dihydroxyindoles mediated by macrophage migration inhibitor factor (MIF) was investigated.…”

“…Oxidative polymerization of a zwitterionic dopa ester[102a] (top), of a dopa ester disulfide (left middle),[102b] formation of 5,6‐dihydroxyindoles by NaIO 4 oxidation of side‐chain substituted DA under controlled conditions (bottom). [102b]…”

Mucopenetrating Zwitterionic Micelles

“…The number of used monomers to synthesis polyzwitterions is rather limited focusing on phosphobetaine, carboxybetaines, 2‐methacryloyloxyethyl phosphorylcholine, and sulfobetaines. However, alternative monomers such as serine methacrylate and ornithine methacrylamide to obtain amino‐acid‐based zwitterionic polymers, or a zwitterionic dopamine derivative started to emerge. Zwitterionic materials are essential for life illustrated by specific phospholipids or osmolytes, inspiring scientists in material design.…”

Catechol‐conjugated Dextran for Marine Antifouling Applications: The Adverse Effects of High Catechol Content

“…Because of the ion-dipole interactions between zwitterions and water molecules, hydration layers are formed on the zwitterionic-polymer-coated surfaces, preventing marine fouling. [22][23][24] Zhang et al reported that coating glass surfaces with poly(sulfobetaine methacrylate) makes them superhydrophilic. 24 Notably, these polymer-coated glass surfaces exhibited an excellent marine antifouling ability, preventing marine diatoms from adhering to the surface.…”

“…The same principle for inhibiting marine fouling was also implemented using zwitterionic polymers. Because of the ion–dipole interactions between zwitterions and water molecules, hydration layers are formed on the zwitterionic‐polymer‐coated surfaces, preventing marine fouling 22–24 . Zhang et al .…”