A Super-Adhesive 2D Diamond Smart Nanofluid with Self-Healing Properties and Multifunctional Applications.

Smart responsive materials are capable of responding to external stimuli and, compared to traditional materials, can be effectively reused and reduce usage costs in applications. However, smart responsive materials often face challenges such as the inability to repair extensive damage, instability in long-term performance, and inapplicability in extreme environments. This study combines 2D diamond nanosheets with organic fluorinated molecules to prepare a smart nanofluid (fluorinated diamond nanosheets, F-DN) with self-healing and self-adhesion properties. This smart nanofluid can be used to design various coatings for different applications. For example, coatings prepared on textured steel plates using the drop-casting method have excellent superhydrophobic and high oleophobic properties; coatings on titanium alloy plates achieve low friction and wear in the presence of lubricating additives of F-DN in perfluoropolyether (PFPE). Most impressively, coatings on steel plates not only provide effective corrosion resistance but also have the ability to self-heal significant damage (approximately 2 mm in width), withstand extremely low temperatures (-64 °C), and resist long-term corrosion factors (immersion in 3.5 wt % NaCl solution for 35 days). Additionally, it can act as a "coating glue" to repair extensive damage to other corrosion-resistant organic coatings and recover their original protective properties. Therefore, the smart nanofluid developed in this study offers diverse applications and presents new materials system for the future development of smart responsive materials.