The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments.Present...The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments.Presently,emphasis has been placed on the development of advanced smart coatings for corrosion protection in different applications.Innovative multifunctional coatings with fascinating stimuliresponsive functionalities are considered“smart”.The stimuli-responsive functionalities of these smart coatings when properly harnessed result in a class of coatings with inherent autonomous control of corrosion.Fundamentally,when metals are exposed to aggressive environments,occurrences at the metalsolution interface cause environmental changes.These changes can be controlled when triggers from external environment set off active components of smart coating,thereby enhancing coating’s life and functionality.Common triggers include the availability of moisture,concentration of chloride ion,p H gradient,mechanical damage,impact,fatigue,light,redox activity and temperature.In this review,recent technological trends in active anticorrosion and self-healing coatings as functional routes for metal protection are summarized,stimuli responsiveness and mechanisms of inhibition are discussed,and recent multi-action protective systems are particularly focused on.展开更多
Conventional nanoparticles incorporated into epoxy coatings suffer from poor compatibility and insufficient corrosion improvement,hindering their practical applications.A dual-strategy approach integrating in-situ hos...Conventional nanoparticles incorporated into epoxy coatings suffer from poor compatibility and insufficient corrosion improvement,hindering their practical applications.A dual-strategy approach integrating in-situ host–vip nanoconfinement and surface self-assembly was devised to fabricate 8HQ@ZIF-8/PDA smart nanocontainers.The vip 8-hydroxyquinoline(8HQ)was encapsulated within the zeolitic imidazolate framework-8(ZIF-8)host,leveraging nanoconfinement effects.A bioinspired polydopamine(PDA)layer was then self-assembled on the 8HQ@ZIF-8 surface through dopamine oxidative self-polymerization,resulting in a robust nanocontainer architecture.Density functional theory(DFT)calculations verify that the molecular interactions between the PDA and the ZIF-8 surface was the chemical adsorption.The resultant 8HQ@ZIF-8/PDA retained the rhombic dodecahedral morphology and crystallinity of ZIF-8,demonstrating controlled pH-responsive release behavior.When incorporated into an epoxy(EP)resin matrix on magnesium alloy,the 8HQ@ZIF-8/PDA/EP smart composite coatings exhibited outstanding interfacial compatibility and long-term stability,achieving a low-frequency impedance(|Z|_(n.n1Hz))of 2.49×10^(7)Ωcm^(2),a maximum phase angle of 82.8°,and a breakpoint frequency(f_(b))of 63.34 Hz after 50 days of immersion in a 3.5 wt%NaCl solution.These findings highlight the exceptional self-healing and corrosion-resistant properties of the 8HQ@ZIF-8/PDA/EP smart composite coatings,underscoring its potential for protecting magnesium alloys in aggressive environments.展开更多
Living organisms rely on materials sequestration from the environment to strengthen their bodies.Such constant activity provides necessary supplies for critical biological functions,which is difficult by man-made stru...Living organisms rely on materials sequestration from the environment to strengthen their bodies.Such constant activity provides necessary supplies for critical biological functions,which is difficult by man-made structures due to the lack of a dynamic sequestration mechanism.In this study,it is shown that an epidermis-like smart coating can respond to changes in salinity to allow a spontaneous and progressive strengthening when supported by steel as a sustained iron source.The self-strengthening is enabled by reaction-coupled diffusion,which makes possible the dynamic sequestration of iron from the in situ rusted steel,partially mimicking the iron accumulation process in a mussel.The emergence of iron-phenolic coordination bonds continuously improves modulus,hardness,and adhesion,achieving a strengthening efficiency comparable to mussel byssus.Interestingly,the bilayer design ensures long-term self-healing performance even during strengthening and a mechanically robust anticorrosion coating with an autonomic protection mechanism and gradually enhanced barrier properties during prolonged service.Our results provide a new venue for the design of stimuli-responsive smart materials characteristic of an open biological system and may serve as the basis for creating highly intelligent devices with sophisticated functionality.展开更多
Coating microdefects and localized corrosion in coating/metal system are inevitable,accelerating the degradation of metal infrastructure.Early evaluating coating microdefects and detecting corrosion sites are urgent y...Coating microdefects and localized corrosion in coating/metal system are inevitable,accelerating the degradation of metal infrastructure.Early evaluating coating microdefects and detecting corrosion sites are urgent yet remain challenge to achieve.Herein,we propose a robust,universal and efficient fluorescence-based strategy for hierarchical warning of coating damage and metal corrosion by introducing the concepts of damage-induced fluorescence enhancement effect(DIE)and ionic-recognition induced quenching effect(RIQ).The coatings with dualresponsiveness for coating defect and steel corrosion are constructed by incorporating synthesized nanoprobes composed of metal organic frameworks(Ni–Zn-MOFs)loaded with Rhodamine B(RhB@MOFs).The initial damage to the coating causes an immediate intensification of fluorescence,while the specific ionic-recognition characteristic of RhB with Fe3t results in an evident fluorescence quenching,enabling the detection of coating damage and corrosion.Importantly,this nanoprobes are insensitive to the coating matrix and exhibit stable corrosion warning capability across various coating systems.Meanwhile,electrochemical investigations indicate that the impedance values of RM/EP maintain above 10^(8)Ωcm^(2)even after 60 days of immersion.Therefore,the incorporation of fluorescent nanoprobes greatly inhibits the intrusion of electrolytes into polymer and improves the corrosion protection performance of the coating.This powerful strategy towards dual-level damage warning provides insights for the development of long-term smart protective materials.展开更多
Smart coating for corrosion protection of metal materials(steel,magnesium,aluminum and their alloys)has drawn great attention because of their capacity to prevent crack propagation in the protective coating by releasi...Smart coating for corrosion protection of metal materials(steel,magnesium,aluminum and their alloys)has drawn great attention because of their capacity to prevent crack propagation in the protective coating by releasing functional molecules(healing agents or corrosion inhibitors)on demand from delivery vehicle,that is,micro/nanocontainer made up of a shell and core material or a coating layer,in a controllable manner.Herein,we summarize the recent achievements during the last 10 years in the field of the micro/nanocontainer with different types of stimuli-responsive properties,i.e.,pH,electrochemical potential,redox,aggressive corrosive ions,heat,light,magnetic field,and mechanical impact,for smart anticorrosion coating.The state-of-the-art design and fabrication of micro/nanocontainer are emphasized with detailed examples.展开更多
The stimuli-responsive anticorrosion coatings have drawn great attention as a prospective corrosion protection approach due to their smart self-repairing properties.In contrast to passive protection mechanism based on...The stimuli-responsive anticorrosion coatings have drawn great attention as a prospective corrosion protection approach due to their smart self-repairing properties.In contrast to passive protection mechanism based on post-corrosion microenvironmental changes,a unique active protection strategy based on nanocatalytic oxygen depletion is proposed in this work to inhibit the occurrence of corrosion.Porous FeeNeC catalysts with outstanding oxygen reduction reaction(ORR)activity(half-wave potential of 0.89 V)is firstly synthesized through pre-coordination with organosilane precursor to obtain homogeneously distributed active sites.When this catalyst is introduced into the coating matrix,uniformly distributed FeeNeC not only compensates the defects but plays a crucial role in adsorption and consumption of diffused oxygen in the coating.Under this dual action,the penetration of corrosive medium,especially oxygen,through coating to metal substrate is greatly suppressed,resulting in effective corrosion inhibition and a significant increase in corrosion resistance of the composite coating compared to pure epoxy coating.This work provides a new perspective and the starting point for the design of high-performance smart coating with active anticorrosion properties.展开更多
Fluorescence-based corrosion detection is an emerging method for surveillance in the early stages of metal corrosion.It is valued for its great responsiveness,non-invasive nature,and capability of in-situ and simultan...Fluorescence-based corrosion detection is an emerging method for surveillance in the early stages of metal corrosion.It is valued for its great responsiveness,non-invasive nature,and capability of in-situ and simultaneous detection.This review paper presents a thorough and up-to-date review of fluorescencebased methods for detecting metal corrosion.It introduces the underlying principles of these detection methods,aligned with the corrosion processes of metals.The paper categorizes fluorescent indicators into those sensitive to pH changes and those responsive to metal ions,both serving as early indicators of corrosion.It also discusses the factors influencing the sensitivity of fluorescence detection and various methods of incorporating fluorescent indicators.Lastly,the paper outlines critical future directions for the betterment of fluorescence-based corrosion diagnosis.展开更多
This article employed a layer-by-layer approach to modify the interfacial boundary of halloysite clay nanotubes(HNTs)using(poly(diallyldimethylammonium chloride))(PDDA)and poly(styrene sulfonate)(PSS)polyelectrolytes ...This article employed a layer-by-layer approach to modify the interfacial boundary of halloysite clay nanotubes(HNTs)using(poly(diallyldimethylammonium chloride))(PDDA)and poly(styrene sulfonate)(PSS)polyelectrolytes to form core(inhibitor-loaded HNTs)-shell(polyelectrolytes layers(PDDA/PSS))structured smart microcapsules or micro-containers.Responses of the smart microcapsules to changes in pH(H^(+)),Cl^(-),OH^(-)and H_(2)O during the release of the loaded inhibitor(2-mecaptobenzothiazole inhibitor(2-MBT))coupled with the number of PDDA/PSS polyelectrolytes layers(n)required to obtain optimal response were characterized.The anticorrosion efficacies of several organic compounds were screened to identify the most suitable inhibitor for the protection of Al alloy 2024 in 3.5 wt.%NaCl.2-MBT which exhibits the best inhibition efficiency was successfully loaded into the HNTs lumen as demonstrated by TGA and DSC results.The release profiles of 2-MBT reveal that the sensitivity of the smart microcapsules to the various external stimuli decreased in the following order:pH>Cl^(-)>H_(2)O>OH^(-);and three-layered polyelectrolyte(3n)displays the highest sensitivity amongst the studied layer numbers(n).The release profiles were fitted to the Pappas and Weibull’s models which describe the release mechanisms.Compatibility of the smart microcapsules with epoxy coating coupled with the anticorrosion effect on Al alloy 2024 substrate were evaluated by means of long-term salt spray and immersion tests.展开更多
The development of smart materials capable of underwater self-healing,mechanical robustness and damage-healing sensing attributes holds great promise for applications in marine energy exploitation.However,achieving ex...The development of smart materials capable of underwater self-healing,mechanical robustness and damage-healing sensing attributes holds great promise for applications in marine energy exploitation.However,achieving excellent humidity self-healing,superior adhesion,and effective damage sensing and monitoring properties simultaneously is challenging because the disturbance of water molecules to dynamic-interaction reconstruction.Herein,inspired by gecko's toes,an ultra-robust environmental adaptative self-healing supramolecular elastomer is designed by molecular engineering of water-insensitive dynamic network,which possesses efficient self-healing and visual damage sensing capabilities.Through coupling design of hierarchical hydrogen bonds,humidity-tolerant catechol coordination and photothermal sensitivity moiety,the elastomer achieves high Young's modulus(157.72 MPa)and superior self-healing efficiency(84.68%).Moreover,the autonomous association between catechol groups and steel surface endows the resultant elastomer with outstanding adhesion force(12.82 MPa)in humid conditions.Furthermore,this elastomer can be fabricated as a patch covered on steel substrates.The damage-healing dynamics and interfacial failure characteristics are visually demonstrated by the reversible fracture and reconstruction of iron-catechol coordination bonds,realizing real-time damage sensing and monitoring.This study provides a novel strategy for the design of next-generation smart protective materials in harsh marine environment,and expected for ensuring the stable operation of marine energy mining equipment.展开更多
基金financial support from the National Natural Science Foundation of China(Nos.52171089 and 51571202)Ling Chuang Research Project of China National Nuclear Corporation。
文摘The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments.Presently,emphasis has been placed on the development of advanced smart coatings for corrosion protection in different applications.Innovative multifunctional coatings with fascinating stimuliresponsive functionalities are considered“smart”.The stimuli-responsive functionalities of these smart coatings when properly harnessed result in a class of coatings with inherent autonomous control of corrosion.Fundamentally,when metals are exposed to aggressive environments,occurrences at the metalsolution interface cause environmental changes.These changes can be controlled when triggers from external environment set off active components of smart coating,thereby enhancing coating’s life and functionality.Common triggers include the availability of moisture,concentration of chloride ion,p H gradient,mechanical damage,impact,fatigue,light,redox activity and temperature.In this review,recent technological trends in active anticorrosion and self-healing coatings as functional routes for metal protection are summarized,stimuli responsiveness and mechanisms of inhibition are discussed,and recent multi-action protective systems are particularly focused on.
基金the Natural Science Foundation of Hunan Province(2024JJ6364)the National Natural Science Foundation of China(52271073)+1 种基金the Sichuan Science and Technology Program(2024NSFJQ0034)the Innovation Team Funds of China West Normal University(KCXTD2024-1).
文摘Conventional nanoparticles incorporated into epoxy coatings suffer from poor compatibility and insufficient corrosion improvement,hindering their practical applications.A dual-strategy approach integrating in-situ host–vip nanoconfinement and surface self-assembly was devised to fabricate 8HQ@ZIF-8/PDA smart nanocontainers.The vip 8-hydroxyquinoline(8HQ)was encapsulated within the zeolitic imidazolate framework-8(ZIF-8)host,leveraging nanoconfinement effects.A bioinspired polydopamine(PDA)layer was then self-assembled on the 8HQ@ZIF-8 surface through dopamine oxidative self-polymerization,resulting in a robust nanocontainer architecture.Density functional theory(DFT)calculations verify that the molecular interactions between the PDA and the ZIF-8 surface was the chemical adsorption.The resultant 8HQ@ZIF-8/PDA retained the rhombic dodecahedral morphology and crystallinity of ZIF-8,demonstrating controlled pH-responsive release behavior.When incorporated into an epoxy(EP)resin matrix on magnesium alloy,the 8HQ@ZIF-8/PDA/EP smart composite coatings exhibited outstanding interfacial compatibility and long-term stability,achieving a low-frequency impedance(|Z|_(n.n1Hz))of 2.49×10^(7)Ωcm^(2),a maximum phase angle of 82.8°,and a breakpoint frequency(f_(b))of 63.34 Hz after 50 days of immersion in a 3.5 wt%NaCl solution.These findings highlight the exceptional self-healing and corrosion-resistant properties of the 8HQ@ZIF-8/PDA/EP smart composite coatings,underscoring its potential for protecting magnesium alloys in aggressive environments.
基金M.Y.thanks the National Natural Science Foundation of China(grant no.22071075)for financial supportS.H.Feng thanks the National Natural Science Foundation of China(grant nos.21831003 and 91959201)for financial support.
文摘Living organisms rely on materials sequestration from the environment to strengthen their bodies.Such constant activity provides necessary supplies for critical biological functions,which is difficult by man-made structures due to the lack of a dynamic sequestration mechanism.In this study,it is shown that an epidermis-like smart coating can respond to changes in salinity to allow a spontaneous and progressive strengthening when supported by steel as a sustained iron source.The self-strengthening is enabled by reaction-coupled diffusion,which makes possible the dynamic sequestration of iron from the in situ rusted steel,partially mimicking the iron accumulation process in a mussel.The emergence of iron-phenolic coordination bonds continuously improves modulus,hardness,and adhesion,achieving a strengthening efficiency comparable to mussel byssus.Interestingly,the bilayer design ensures long-term self-healing performance even during strengthening and a mechanically robust anticorrosion coating with an autonomic protection mechanism and gradually enhanced barrier properties during prolonged service.Our results provide a new venue for the design of stimuli-responsive smart materials characteristic of an open biological system and may serve as the basis for creating highly intelligent devices with sophisticated functionality.
基金support by the National Natural Science Foundation of China(52201077)the Natural Science Foundation of Shandong Province(ZR2022QE191)+1 种基金Elite Scheme of Shandong University of Science and Technology(0104060541123)Talent introduction and Research Start-up Fund of Shandong University of Science and Technology(0104060510124).
文摘Coating microdefects and localized corrosion in coating/metal system are inevitable,accelerating the degradation of metal infrastructure.Early evaluating coating microdefects and detecting corrosion sites are urgent yet remain challenge to achieve.Herein,we propose a robust,universal and efficient fluorescence-based strategy for hierarchical warning of coating damage and metal corrosion by introducing the concepts of damage-induced fluorescence enhancement effect(DIE)and ionic-recognition induced quenching effect(RIQ).The coatings with dualresponsiveness for coating defect and steel corrosion are constructed by incorporating synthesized nanoprobes composed of metal organic frameworks(Ni–Zn-MOFs)loaded with Rhodamine B(RhB@MOFs).The initial damage to the coating causes an immediate intensification of fluorescence,while the specific ionic-recognition characteristic of RhB with Fe3t results in an evident fluorescence quenching,enabling the detection of coating damage and corrosion.Importantly,this nanoprobes are insensitive to the coating matrix and exhibit stable corrosion warning capability across various coating systems.Meanwhile,electrochemical investigations indicate that the impedance values of RM/EP maintain above 10^(8)Ωcm^(2)even after 60 days of immersion.Therefore,the incorporation of fluorescent nanoprobes greatly inhibits the intrusion of electrolytes into polymer and improves the corrosion protection performance of the coating.This powerful strategy towards dual-level damage warning provides insights for the development of long-term smart protective materials.
基金the National Natural Science Foundation of China (Nos.41576079,41922040)the Qingdao National Laboratory for Marine Science and Technology (No.QNLM20160RP0413)the AoShan Talent Program Supported by Qingdao National Laboratory for Marine Science and Technology (No.2017ASTCP-ES02)
文摘Smart coating for corrosion protection of metal materials(steel,magnesium,aluminum and their alloys)has drawn great attention because of their capacity to prevent crack propagation in the protective coating by releasing functional molecules(healing agents or corrosion inhibitors)on demand from delivery vehicle,that is,micro/nanocontainer made up of a shell and core material or a coating layer,in a controllable manner.Herein,we summarize the recent achievements during the last 10 years in the field of the micro/nanocontainer with different types of stimuli-responsive properties,i.e.,pH,electrochemical potential,redox,aggressive corrosive ions,heat,light,magnetic field,and mechanical impact,for smart anticorrosion coating.The state-of-the-art design and fabrication of micro/nanocontainer are emphasized with detailed examples.
基金financially supported by the“National Natural Science Foundation of China”(52304072)“Funded by Shandong Postdoctora1 Science Foundation”(SDBX2023019)+1 种基金the“Fundamental Research Funds for the Central Universities”(23CX06022A)the“Applied Research Project of Qingdao Postdoctoral Researchers”(QDBSH20230202010).
文摘The stimuli-responsive anticorrosion coatings have drawn great attention as a prospective corrosion protection approach due to their smart self-repairing properties.In contrast to passive protection mechanism based on post-corrosion microenvironmental changes,a unique active protection strategy based on nanocatalytic oxygen depletion is proposed in this work to inhibit the occurrence of corrosion.Porous FeeNeC catalysts with outstanding oxygen reduction reaction(ORR)activity(half-wave potential of 0.89 V)is firstly synthesized through pre-coordination with organosilane precursor to obtain homogeneously distributed active sites.When this catalyst is introduced into the coating matrix,uniformly distributed FeeNeC not only compensates the defects but plays a crucial role in adsorption and consumption of diffused oxygen in the coating.Under this dual action,the penetration of corrosive medium,especially oxygen,through coating to metal substrate is greatly suppressed,resulting in effective corrosion inhibition and a significant increase in corrosion resistance of the composite coating compared to pure epoxy coating.This work provides a new perspective and the starting point for the design of high-performance smart coating with active anticorrosion properties.
基金financially supported by the National Natural Science Foundation of China(Nos.52171089 and 51571202)the Liaoning Province International Science and Technology Coopera-tion Program Project(No.2024JH2/101900013)+1 种基金the Key Program of Basic Research Projects of Liaoning Provincial Department of Edu-cation(No.JYTZD2023114)the LingChuang Research Project of China National Nuclear Corporation(No.E041F212Z1).
文摘Fluorescence-based corrosion detection is an emerging method for surveillance in the early stages of metal corrosion.It is valued for its great responsiveness,non-invasive nature,and capability of in-situ and simultaneous detection.This review paper presents a thorough and up-to-date review of fluorescencebased methods for detecting metal corrosion.It introduces the underlying principles of these detection methods,aligned with the corrosion processes of metals.The paper categorizes fluorescent indicators into those sensitive to pH changes and those responsive to metal ions,both serving as early indicators of corrosion.It also discusses the factors influencing the sensitivity of fluorescence detection and various methods of incorporating fluorescent indicators.Lastly,the paper outlines critical future directions for the betterment of fluorescence-based corrosion diagnosis.
基金the financial supports from the National Natural Science Foundation of China(Nos.51871227 and 51671198)financial support from the Shenzhen Science and Technology Innovation Council(No.JCYJ20170413141208098)+2 种基金the Innovation Technology Fund(No.9440175)the Research Grants Council of Hong Kong(Nos.C1018-17G and 11275216)the City University of Hong Kong(Nos.9360140 and 9667139)
文摘This article employed a layer-by-layer approach to modify the interfacial boundary of halloysite clay nanotubes(HNTs)using(poly(diallyldimethylammonium chloride))(PDDA)and poly(styrene sulfonate)(PSS)polyelectrolytes to form core(inhibitor-loaded HNTs)-shell(polyelectrolytes layers(PDDA/PSS))structured smart microcapsules or micro-containers.Responses of the smart microcapsules to changes in pH(H^(+)),Cl^(-),OH^(-)and H_(2)O during the release of the loaded inhibitor(2-mecaptobenzothiazole inhibitor(2-MBT))coupled with the number of PDDA/PSS polyelectrolytes layers(n)required to obtain optimal response were characterized.The anticorrosion efficacies of several organic compounds were screened to identify the most suitable inhibitor for the protection of Al alloy 2024 in 3.5 wt.%NaCl.2-MBT which exhibits the best inhibition efficiency was successfully loaded into the HNTs lumen as demonstrated by TGA and DSC results.The release profiles of 2-MBT reveal that the sensitivity of the smart microcapsules to the various external stimuli decreased in the following order:pH>Cl^(-)>H_(2)O>OH^(-);and three-layered polyelectrolyte(3n)displays the highest sensitivity amongst the studied layer numbers(n).The release profiles were fitted to the Pappas and Weibull’s models which describe the release mechanisms.Compatibility of the smart microcapsules with epoxy coating coupled with the anticorrosion effect on Al alloy 2024 substrate were evaluated by means of long-term salt spray and immersion tests.
基金supported by the National Natural Science Foundation of China(52201077,52401096)the Natural Science Foundation of Shandong Province(ZR2022QE191,ZR2024QE462)the Project 24-4-4-zrij-54-jch supported by Qingdao Natural Science Foundation and State Key Laboratory of Marine Coatings Funded Project(02030124902)。
文摘The development of smart materials capable of underwater self-healing,mechanical robustness and damage-healing sensing attributes holds great promise for applications in marine energy exploitation.However,achieving excellent humidity self-healing,superior adhesion,and effective damage sensing and monitoring properties simultaneously is challenging because the disturbance of water molecules to dynamic-interaction reconstruction.Herein,inspired by gecko's toes,an ultra-robust environmental adaptative self-healing supramolecular elastomer is designed by molecular engineering of water-insensitive dynamic network,which possesses efficient self-healing and visual damage sensing capabilities.Through coupling design of hierarchical hydrogen bonds,humidity-tolerant catechol coordination and photothermal sensitivity moiety,the elastomer achieves high Young's modulus(157.72 MPa)and superior self-healing efficiency(84.68%).Moreover,the autonomous association between catechol groups and steel surface endows the resultant elastomer with outstanding adhesion force(12.82 MPa)in humid conditions.Furthermore,this elastomer can be fabricated as a patch covered on steel substrates.The damage-healing dynamics and interfacial failure characteristics are visually demonstrated by the reversible fracture and reconstruction of iron-catechol coordination bonds,realizing real-time damage sensing and monitoring.This study provides a novel strategy for the design of next-generation smart protective materials in harsh marine environment,and expected for ensuring the stable operation of marine energy mining equipment.
