Modified chitosan/SiO2 hybrid nano-composite corrosion inhibitor for the protection of mild steel

Purpose This study aims to fabricate an organic-inorganic hybrid nanocomposite inhibitor (CLS) by innovatively integrating inorganic fillers into a chitosan-based matrix (CL), followed by a comprehensive evaluation of its anticorrosion properties for mild steel in HCl medium. Design/methodology/approach This study designed an organic–inorganic hybrid inhibitor CLS by strategically integrating SiO2 nanoparticles into an L-tryptophan-modified CS matrix CL. The design rationale was to leverage a synergistic “anchor-and-fill” mechanism: the chemically modified CL acts not only as a primary corrosion-inhibiting moiety through strong chemisorption onto the steel surface but also as a dispersing agent and polymeric scaffold for the inorganic phase. The incorporated SiO2 nanoparticles, in turn, are intended to enhance the hydrophobicity (102.88° contact angle) and mechanical integrity of the formed protective film. The anti-corrosion properties of this designed composite were comprehensively evaluated for mild steel in HCl medium. Findings These analyses ultimately elucidated the corrosion inhibition mechanism of the organic/inorganic hybrid nanocomposite. The concept of this organic/inorganic hybrid inhibitor opens new directions for the development of low-concentration, high-efficiency green corrosion inhibitors, with the potential to inject new vitality into the field of metal corrosion protection. Originality/value This study aims to achieve a synergistic hybrid of organic and inorganic components, overcoming the limitations of single modification methods, further improving the corrosion performance of CS derivatives, and elucidating the mechanisms of organic/inorganic hybridization to lay a foundation for future research.