Manipulating a smart multi-functional nano-carrier based on l-cysteine-GO-ZIF67@ZIF8 core@shell MOFs-LDH for designing an excellent self-healing coating

A novel nano-carrier with tertiary-level corrosion suppression functionalities, i.e., an excellent/long-period barrier against water diffusion/ Cl− ions transfer, high corrosion inhibiting materials loading capacity, and smart (pH-triggered and ion exchange release mechanisms) long-period inhibitor release features were designed. This was done via the nitrate ions intercalated Zn-Al-LDH (LD) 2D-crystals synthesis over the reduced graphene oxide (r-GO) nano-layers, and then in-situ coverage of hierarchically Co-2Im (ZI67-core)/Zn-2Im (shell) and Zn-2Im (core)/Co-2Im (shell) porous MOFs over the r-GOLD nano-hybrids. Monosodium glutamate (SGL) anionic inhibitor was loaded into the inter-galleries of LDH layers and porosities of ZI67/ZI8 and/ or ZI8/ZI67 core@shell structure via ions-exchange and vacuum methods. Characterization of the r-GOLD-ZI67/ZI8 as well as r-GOLD-ZI8/ZI67 core@shell structures was done by various technics. From the polarization test outcomes the mixed corrosion mitigation effect together with high inhibition index of (>95%) was recorded in the saline solution that contained bare metal and SGL-loaded r-GOLD-ZI67/ZI8 core@shell extract. After loading the Core@shell nano-hybrids (containing SGL) into the epoxy coating, the long-term and durable (maintained for about 112 days of exposure) physical water shielding (fb<0.01 Hz,|Z|>1010.5ohm.cm2, Rt>60Gohm.cm2) against ions (Cl-)/water diffusion was obtained due to r-GOLD layers well dispersion, prolonging diffusion paths.