Abstract
Coatings with multiple protective properties are highly desired for
anti-corrosion purposes as they overcome the limitations of conventional
coatings that have limited functionality in field applications. Thus,
this study describes the protective mechanisms of a new class of
composite coatings fabricated by embedding benzotriazole (BTA) laden
nanotubes prior-functionalized with interfacial wrappings of chitosan
hydrogel (CTSH) entrapping excess crosslinking agents (glutaraldehyde
(GTRA) or epichlorohydrin (EPIH)) in epoxy (E44) matrix cured with
polyamide. The modification led to an improvement in the barrier and
physical properties of the composite coatings and introduced
shape-memory self-repairing capabilities. Long-term impedance
spectroscopy (EIS) complemented with the physical property tests was
employed to interrogate the improved barrier properties. The coatings'
microstructure and composition analyzed with SEM and EDS reveal the
shape-memory self-repairing effect which was further characterized with
overtime optical snapshots of samples exposed in a salt-spray chamber.
The antibacterial functionality of the composite coatings against some
marine bacteria (Marinobacter aquaeolei and Marinobacter salsuginis)
was characterized using combined SEM and confocal laser scanning
microscopy (CLSM). UV–visible spectrophotometry data reveal the
pH-responsive release of the entrapped functional materials from the
composite coatings. The experimental findings show that the new
composite coatings exhibited intriguing triple-action protective
functionalities and were more effective in protecting Q235 carbon steel
exposed to 3.5 % NaCl compared to the conventional epoxy coating. This
suggests that comparatively, the composite coatings have promising
applications in structures that are exposed to sea environments.
Original language | English |
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Article number | 130851 |
Journal | Surface and Coatings Technology |
Volume | 484 |
ISSN | 0257-8972 |
DOIs | |
Publication status | Published - 2024 |
Keywords
- Anti-bacterial
- Barrier coatings
- CLSM
- Clay nanotubes
- Corrosion inhibition
- EIS
- Self-repairing