Synergistic corrosion protection and bacterial control in a UV-cured UA coating containing TiO2–polyaniline–calixarene nanocomposite

An innovative nanocomposite architecture—TiO 2 –polyaniline‑doped sulfonated calixarene‑GMA (TiO 2 –PA–GSC)—is engineered for integration into UV‑curable waterborne urethane‑acrylate coatings. This design delivers concurrent improvements in cross‑link density, thermal stability (ΔT₅₀% = +31 °C), and electrochemical barrier properties with low‑frequency impedance rising by up to two orders of magnitude during long‑term immersion. The synergistic mechanism comprises: (i) polyaniline‑mediated formation of a redox‑active passive layer, (ii) TiO 2 nanoparticles imparting tortuous diffusion pathways and interfacial charge‑trapping, and (iii) sulfonated calixarene facilitating homogeneous dispersion, cross-linking, and selective metal‑ion complexation. Furthermore, the coating demonstrates Gram‑positive‑selective antibacterial efficacy, exhibiting complete inhibition of Staphylococcus aureus (95.6%, 12 ± 1 mm zone) with negligible activity against Escherichia coli (≈ 10% inhibition). This integrated multifunctional platform advances protective coating technology by simultaneously addressing corrosion degradation and microbial colonization in demanding saline environments.