Graphene skeletal nanotemplate coordinated with pH-Responsive porous Double-Ligand Metal-Organic frameworks (DL-MOFs) through ligand exchange theory for High-Performance smart coatings

For the first time, thermally stable and high-performance pH-responsive anti-corrosive nanoreservoirs based on double-ligand zinc phosphate framework (ZPF) decorated graphene oxide skeletal template (G-ZPF) was pre-pared through the ligand exchange theory. The G-ZPF nanoreservoirs, and pristine materials were monitored by X-ray diffraction (XRD), Thermo gravimetric analysis (TGA), Field emission scanning electron microscopy (FE-SEM), Fourier transforms infrared (FT-IR) spectroscopy, and Brunauer-Emmett-Teller (BET) analyses. The out-comes revealed that a highly thermal stable double-ligand porous coordination polymer was synthesized prop-erly. pH-responsive corrosion inhibitors release ability of G-ZPF nanoreservoirs was studied in the acidic, neutral, and alkaline saline (3.5 wt% concentration of NaCl) solutions, and the release rate of active corrosion inhibiting substances (Zinc and phosphate ions, and 2-methylimidazole molecules) was measured by inductively coupled plasma-optical emission spectrometry (ICP-OES), and total organic carbon (TOC) techniques. Electrochemical (polarization, and EIS), and surface analyses were conducted for investigating the G-ZPF nanoreservoirs corro-sion inhibition ability in the saline solution, and mild steel samples coated with the epoxy-polyamide incorpo-rated with G-ZPF nanoreservoirs in intact and scratched forms. The results showed that structural inhibitors -loaded G-ZPF nanoreservoirs guarantee both active (self-healing), and passive (ion-water barrier) characteris-tics of the organic coating. The results of Pull off, salt spray, cathodic disbonding, dynamic mechanical analysis (DMTA), and tensile tests showed robust corrosion prevention and excellent thermo/mechanical performance of the epoxy-polyamide coating loaded with G-ZPF nanoreservoirs.

Automated summary

Thermally stable and high-performance pH-responsive anti-corrosive nanoreservoirs based on double-ligand zinc phosphate framework (ZPF) decorated graphene oxide skeletal template (G-ZPF) were prepared through ligand exchange theory. The nanoreservoirs showed active corrosion inhibiting substance release ability and corrosion inhibition ability in saline solutions. They also enhanced the corrosion prevention and thermo/mechanical performance of the epoxy-polyamide coating.