In this work, a novel electroactive silsesquioxane precursor, N-(3-triethoxysilylpropylureido) aniline tetramer (TESPAT), was synthesized via one-step coupling reaction between phenyl-capped aniline tetramer (AT) and 3-(triethoxysilyl)propyl isocyanate (TESPIC) under mild conditions. The chemical structure and electroactivity of the resulting silsesquioxane precursor were investigated by FTIR, NMR, UV-vis spectra, and cyclic voltammetry. Subsequently, the sol–gel reactions of TESPAT with triethoxymethylsilane (TEMS) at various compositions were carried out to achieve new electroactive siliceous hybrid materials with good thermal stability. Furthermore, polarization curves and electrochemical impedance spectroscopic (EIS) measurements indicated that the obtained hybrid materials exhibit remarkably enhanced corrosion protection on Q235 electrodes as compared to pure silica coating. The significantly improved anticorrosion performance is attributed to the redox catalytic capabilities of the AT units in the hybrid materials.

Corrosion of aluminum alloys (Al alloys) has been a ubiquitous problem, and this seriously restricts its range of applications.

In this work, a water-soluble host–guest complex containing carboxymethylated beta-cyclodextrin (CM-β-CD) and an aniline trimer (AT) was synthesized. The application of AT–CM-β-CD as an inhibitor for alleviating the corrosion of Q235 carbon steel in 1 M HCl solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Results showed that the inhibition efficiency was significantly increased in the presence of AT–CM-β-CD, and the inhibition efficiency was up to 99.2% when the concentration of AT–CM-β-CD was 250 mg L⁻¹. Field emission scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) confirmed that the corrosion inhibitor had excellent corrosion inhibition effects due to the formation of an adsorption film on the surface of Q235 carbon steel. According to the data extracted from the Langmuir adsorption model, AT–CM-β-CD absorption involves both physisorption and chemisorption.

Given their outstanding versatile properties, multilayered anticorrosion coatings have drawn great interest from researchers in the academic and engineering fields. However, the application of multilayered coatings is restricted by some limitations such as low interlayer compatibilities, the harsh preparation process, etc. This work introduced a composite film fabricated on a 2A12 aluminum alloy surface, including an anodic oxide film, a sol–gel film, and a layer-by-layer (LBL) self-assembling film from bottom to top. The microstructure and elemental characterization indicated that the finish of the coating with the LBL film resulted in a closely connected multilayered coating with a smoother surface. The anticorrosion performance was systematically evaluated in the simulated corrosive medium and neutral salt spray environment. The integrated coating with the LBL film presented an excellent anticorrosion ability with system impedance over 10⁸ Ω·cm² and a self-corrosion current density two orders of magnitude lower than that of the other coatings. After the acceleration test in a salt spray environment, the multilayered coatings could still show a good protective performance with almost no cracks and no penetration of chloride ions. It is believed that the as-constructed multilayered coating with high corrosive properties and a fine surface state will have promising applications in the field of anticorrosion engineering.