Self-Healing Superhydrophobic Coatings with Multiphase Repellence Property

Abstract

Developing versatile, scalable, and durable coatings that repel various matters in different service environments is of great importance for engineered materials applications but remains highly challenging. Here, the mesoporous silica microspheres (HMS) fabricated by the hard template method were utilized as micro-nanocontainers to encapsulate the hydrophobic agent of perfluorooctyltriethoxysilane (F13) and the corrosion inhibitor of benzotriazole (BTA), forming the functional microsphere of F-HMS(BTA). Moreover, the synthesized organosilane-modified silica sol adhesive (SMP) and F-HMS(BTA) were further employed as the binder and functional filler to construct a superhydrophobic self-healing coating of SMP@F-HMS(BTA) on various engineering metals through scalable spraying. The prepared coating exhibits good mechanical durability and strong resistance to accretion of multiphase substances including large molecule compounds, liquids, and ice crystals, demonstrating good antifouling and anti-icing properties. Moreover, the coatings possess hydrophobic and anticorrosion self-healing properties owing to the self-migration release of the functional additives in the micro-nanocontainers, showing the “active–passive” synergistic properties mechanism. At a frequency of 0.01 Hz, the charge transfer resistance R_ct and the constant phase element C_cpe were measured to be 2.62 × 10⁹ Ω cm² and 9.63 × 10^–10 F cm², respectively. In addition, the corrosion current density was reduced by 3–5 orders of magnitude, indicating superior corrosion resistance. This work provides a feasible strategy to prepare functional protective coatings for a wide range of applications in addressing adhesion and corrosion issues.