Carbon aerogel micro-nanocontainers for high-performance anticorrosive and self-repairing coatings featuring high loading rate, low conductivity, and pH-related release

This work developed APTES-modified sodium alginate-based carbon aerogels (Si-SACA) as smart micro-nanocontainers to enhance epoxy coatings (EP) with superior corrosion resistance and autonomous self-healing functionality. The composite achieved a 29.02 % benzotriazole (BTA) loading via Multiple interactions and demonstrated pH-responsive release kinetics. Electrochemical testing revealed that 0.2 wt% BTA@Si-SACA/EP coatings maintained exceptional barrier properties (|Z| f =0.01Hz  > 10 10  Ω·cm 2 after 50-day immersion in 3.5 % NaCl), outperforming pure EP by two orders of magnitude. Meanwhile, the scratched 0.2 wt% BTA@Si-SACA/EP coating shows a certain self-repairing ability and corrosion resistance with the rise of the low-frequency modulus value to 5.25 × 10 4  Ω·cm 2 after 48 h of immersion. The self-healing ability comes from the release of BTA molecules and their chelation with the metal substrate to form an inert protective film.