Research On The Fabrication Of Biomimetic High-Adhesion Coating With Anticorrosion And Antifouling Performance

Widespread corrosion of metals causes serious economic losses worldwide.A series of corrosion prevention research work provides effective corrosion inhibition program,in which elastomer materials are commonly used in metal corrosion prevention,anti-fouling,anti-cavitation coating construction.Such coatings in the initial stage can effectively resist corrosion,with the extension of service time,metal interface corrosion induced by elastomer coating adhesion rapidly decreased,resulting in coating peeling failure.Especially in the marine corrosion,fouling,cavitation environment,metal-elastomer rigid-flexible interface premature delamination is more serious,the coating adhesion will not be able to meet the high adhesion performance requirements of anti-corrosion coatings.Strong and stable interfacial adhesion is the key to realize the long-lasting function of the coating.Aiming at the problems of insufficient adhesion and weak interfacial corrosion inhibition of traditional elastomeric coatings,the research utilizes bionic strategies to develop a series of technical routes to enhance the active corrosion inhibition,passive barrier and interfacial cross-linking capabilities of the coatings.The study starts from three perspectives of substrate bionic structural processing,interface anti-corrosion strengthening and material composite modification to prepare a series of high adhesion elastomer coating system to solve the weak interfacial bonding and corrosion inhibition of elastomeric anti-corrosion and antifouling coatings,and to provide technological support for the realization of long-lasting and stable application of elastomeric functional coatings in corrosive environments.The research is carried out in four chapters to construct biomimetic high adhesion anticorrosion and antifouling coating systems applicable to different scenarios,the main contents are as follows:1.Integrated assembly of rigid-flexible interfaces for pearl-like layer brick-mortar structural anti-corrosion coatings.A pearl-like layer brick-mortar structure anti-corrosion primer with random distribution of MNSs and regional enrichment of Fe₃O₄@mSiO₂/MBT was developed by integrating prepared mica nanosheets（MNSs）and magnetically responsive mesoporous nanoparticles（Fe₃O₄@mSiO₂/MBT）under magnetic field induction.After magnetron-induced assembly,Fe₃O₄@mSiO₂/MBT enriched at the bottom responds quickly to release the corrosion inhibitor MBT,forming a passivation layer at the corrosion site to inhibit corrosion,and its corrosion inhibitory property is enhanced by 30.36%.The formation of a pearl-like brick-mortar structure by the MNSs and the organic system greatly improves the corrosive shielding property of the composite coating,and the impedance modulus is higher compared with that of the undoped MNSs after a corrosive seawater soak for 30 d.The MNSs and organic system are also more effective in preventing corrosion than the undoped MNSs.After 30 d of seawater corrosion immersion,the impedance modulus value of the composite coating was improved by 5 orders of magnitude compared with that of the undoped MNSs sample.The nanocomposite primer has strong interfacial adhesion（10.9 MPa）and covalently crosslinks elastomeric antifouling and cavitation topcoats.Its covalently crosslinked elastomer adhesion（2.2 MPa）was approximately 3.5 times higher than physical adhesion（0.6 MPa）.The integrated assembly of rigid and flexible interfaces enhances the adhesion performance of traditional elastomeric coating substrates and imparts anti-cavitation and anti-fouling properties to the rigid interfaces.The corrosion inhibition layer primer combined with the anti-fouling and anti-cavitation layer paint further improves the shielding of the coating against corrosive media.2.Preparation and optimization of cross-linking interlocking structure of bionic iron beetle sheath-wing sutures.In order to simplify the introduction of chemically reactive active sites in elastomeric topcoat materials and the pre-curing process of primer,and to realize the universality of rigid-flexible interfacial adhesion enhancement,inspired by the crosslinked interlocking structure of sheath-wing sutures of the iron beetle（Phloeodes diabolicus）,simple magnetic molding technology was used to create interlocking microarrays for enhanced heterogeneous assembly.Thanks to the interfacial cross-linking of the bionic microarray structure,the tensile adhesion of the polydimethylsiloxane（PDMS）coatings was increased by 270%and the shear resistance by 520%,which is close to the tensile limit of PDMS（2.2 MPa）.The bionic structure can be prepared on a variety of substrates such as glass,aluminum alloy,and brass surfaces,and also has significant adhesion enhancement effects on commonly used elastomeric materials such as polyurethane（PU）,demonstrating the universality of substrate,material interface anchoring.The interlocking structure arrays are optimized and the anchoring mechanism is analyzed through validation experiments and finite element analysis methods,and 3D printing is used to replicate the bionic structures and prepare microarray structures on a variety of curved substrate surfaces in a variety of materials.The replica bionic structures enhance the interfacial bonding of heterogeneous materials such as polytetrafluoroethylene（PTFE）and non-adhesive materials such as PDMS.In engineering applications,the bionic interlocking structures provide inspiration and technical support for realizing durable bonding at incompatible interfaces.3.Construction of high adhesion anticorrosion and antifouling system with bionic interlocking structure.Interfacial adhesion performance is related to material adhesion and material cohesion,strengthening material cohesion can enhance interfacial adhesion.Due to the defective cohesion of elastomer PDMS,the crosslinking system is insufficient to fully realize the anchoring performance of bionic interlocking structure.In order to strengthen the interfacial anchoring,this work performed material composite modification to prepare elastomeric polyurethane-polyamide（PUPI）materials with high mechanical stability.The bionic interlocking structure-anchored elastomeric PUPI coating exhibits strong adhesion performance of 10.8 MPa and maintains long-lasting adhesion stability.The interlocking structure provides strong cross-linking and corrosion inhibition effects compared to conventional sandblasting and silane coupling agent surface treatment strategies.The coating on the blank substrate surface exhibited low initial adhesion（4.2 MPa）and retained only about 20%of its adhesion strength after 30 d of immersion.The PUPI coatings integrated with the microarrays exhibited excellent corrosion resistance,cavitation resistance,and long-term adhesion.Composite capsaicin biomolecule PUPI@CAP realizes efficient green antifouling properties.4.Self-assembled ZIF-L structures for enhanced interfacial anchoring and corrosion inhibition of anti-corrosion and anti-fouling coatings.In order to achieve simple structural anchoring and corrosion inhibition enhancement effects,this work performs a self-assembly strategy of metal-ion framework structures（ZIF-L）to cross-link biobased elastic oxazine polymer PUBO antifouling coatings.This work assembles ZIF-L structures on the surface of Fe,Al or Cu substrates by in situ growth method for efficient corrosion protection and coating interface anchoring,which greatly improves the interfacial corrosion inhibition effect and adhesion performance of elastomeric coatings such as PUBO and PDMS.ZIF-L as a cross-linking and corrosion inhibition layer can greatly improve the interfacial bonding and stability of the synthesized PUBO materials on metal substrates.Due to the introduction of the bionic structure ZIF-L,the interfacial bonding of PDMS and PUBO with metal was enhanced to 475%and 192%of the original.As the ZIF-L structure decomposes rapidly under alkaline conditions to release the corrosion inhibitor dimethylimidazole（MI）to inhibit the corrosion of the metal,the ZIF-L structure remains on the surface of the metal substrate even after removal of the organic coated portion by pulling test to provide long-lasting corrosion protection for the metal.This bionic crosslinking system solves the defect of unstable adhesion of polymer functional coatings,and provides a solution for various functional coatings to maintain long and stable adhesion in corrosive environments.