Encapsulating polyaniline within porous MIL-101 for high-performance corrosion protection

The metal corrosion possesses a serious threat to the safety and loss of property. The anticorrosion study on metal-organic frameworks (MOFs) remains rarely reported. Therefore, it is desirable to build MOFs-based anticorrosion coating with long-term corrosion resistance. Herein, we prepared a novel MOF-polymer anticorrosion composite PANI@MIL-101 by encapsulating polyaniline (PANI) within the pores of MIL-101 with in-situ polymerization of aniline monomer. The N₂ adsorption-desorption and transmission electron microscopy (TEM) of PANI@MIL-101 illustrate that PANI is successfully encapsulated in the pores of MIL-101 with in-situ polymerization. PANI@MIL-101 was dispersed in epoxy resin (EP) to prepare anti-corrosive coatings. The Tafel potentiodynamic polarization measurements and electrochemical impedance spectroscopy show that PANI@MIL-101/EP coating system has superior corrosion protection with the lowest i_corr value and the highest |Z|_0.01 value compared with MIL-101/EP coating, PANI/EP coating and EP coating. A possible anticorrosion mechanism of PANI@MIL-101 was discussed. This work reveals that MOF-polymer composite materials are superb candidates for high-performance corrosion protection.