Self-healing Behavior Regulation And Anti-corrosion Mechanism Of Silicone Oil-based Composites

In the field of corrosion protection,organic coatings effectively protect metal substrates and prevent corrosion reactions.However,the microcracks and pores of the coating caused by the external environment and mechanical damage can induce local corrosion.Self-healing material is a new type of intelligent material that can automatically sense and repair damage and has great potential in intelligent anti-corrosion coatings.The disadvantage of traditional self-healing anticorrosive coatings is that they cannot achieve precise directional repair.At the same time,there are a large number of fouling organisms in the complex marine environment,which requires the self-healing coating to have excellent anti-corrosion performance while also taking into account anti-fouling properties.Inspired by the natural phenomenon of "no traces from the ship passing through the water",the fluid silicone oil quickly restore the original state after external force as the driving force for self-healing to prepare silicone oil-based self-healing composite materials.The modified nano-filler is used as thickeners to form the three-dimensional particle network in silicone oil to increase the viscosity,stability and anti-corrosion performance of silicone oil-based composites.This article studies the self-healing behavior regulation and anti-corrosion mechanism of oil-based composites.The main research content and conclusions of this article are as follows:(1)The magnetic filler of rGO-Fe3O4 is prepared by the hydrothermal synthesis method,and rGO-Fe3O4 is evenly dispersed in silicone oil to prepare rGO-Fe3O4/Oil.The synergistic effect of the magnetic responsiveness and impermeability of rGO-Fe3O4 makes the flowable rGO-Fe3O4/Oil move to the corrosion target area with the action of the magnetic field,effectively inhibiting local corrosion.The effect of rGO-Fe3O4 content on the corrosion performance of rGO-Fe3O4/Oil in 3.5 wt%NaCl solution is studied.The results show that when the filler added in the oil film is 7.5 wt%,the low-frequency impedance modulus is still as high as 2.0×1010 ?·cm2 after immersing in the corrosive solution for 384 h,showing excellent anticorrosion performance.This is mainly due to the efficient dispersion of rGO-Fe3O4 in silicone oil to construct a labyrinth structure with good barrier properties,which effectively inhibits the penetration and diffusion of corrosive media.(2)The attapulgite as the nano-container to adsorb 2-undecylimidazoline corrosion inhibitor to prepare ATP@ULM filler,and ATP@ULM filler is uniformly dispersed in silicone oil to prepare anti-corrosion and anti-fouling dual-effect ATP@ULM/Oil coating.The corrosion protection performance of ATP@ULM/Oil is investigated through electrochemical tests.The research results show that the low-frequency impedance modulus of ATP@ULM/Oil-7.5 wt%after being immersed in the corrosion solution for 20 days is still stable at 1010 ?·cm2.This is mainly because the synergistic protective effect of attapulgite and 2-undecylimidazoline effectively improves the long-term anti-corrosion performance of ATP@ULM/Oil.The antifouling performance of ATP@ULM/Oil is investigated by the biological laser copolymerization microscope test and the 24 h inhibition zone experiment of Escherichia coli.The results show that 2-undecylimidazoline has excellent antibacterial performance.ATP@ULM/Oil reduces the fouling biological activity and has excellent antibacterial and anti-algae functions.(3)The particle network formed by rGO-Fe3O4 and ATP@ULM nano-fillers in silicone oil can effectively improve the viscosity and stability of silicone oil-based composites.The self-healing behavior of silicone oil-based composites is studied by the open circuit potential test and the scratch self-healing test in different corrosive environments.The results show that the silicone oil-based composite material can achieve repeatable self-heal without external triggering in air,underwater,acid(pH=1),alkali(pH=14),and salt(pH=7)corrosion solutions.The corrosion protection performance of each self-healing process is restored to the initial state within hundreds of seconds,and the silicone oil-based composite material exhibits highly efficient and repeatable self-healing performance.