To construct structurally stable sulfur cathode of Li-S battery with improved cycling performance,poly(acrylic acid)(PAA)crosslinked by cationic hydroxypropyl polyrotaxane(HPRN+)via dynamically reversible boronic este...To construct structurally stable sulfur cathode of Li-S battery with improved cycling performance,poly(acrylic acid)(PAA)crosslinked by cationic hydroxypropyl polyrotaxane(HPRN+)via dynamically reversible boronic ester bonds is synthesized and serves as the cathode binder.The smart polymer networks offer multifunction including buffering the volume change of the cathode during charge/discharge through the pulley effect of polyrotaxanes(PR),suppressing the shuttle effect by adsorption of polysulfide using the plentiful carboxyl,hydroxyl and quaternary ammonium cationic groups,and self-healing the micro-damages to ensure stable conduction pathways of the electrode.As a result,the Li-S batteries based on this novel multifunctional binder and simple commercial sulfur/carbon composites cathode exhibit excellent specific capacity and cycling stability.In particular,the specific capacity decay per cycle of the cell is only 0.064%along with high Coulombic efficiency after 550 cycles at 1.0 C,which is superior to most of the reported binders.Even under high sulfur loading,moreover,the cathode can deliver superior areal capacity and cycling stability.This proposed binder provides a new way for the design of high-stability sulfur cathodes.展开更多
Magnesium and its alloys have gained relevance for their light-weight combined with a high value of strength-to-weight ratio,which makes them useful in fields such as aerospace,automotive as well as biomedical enginee...Magnesium and its alloys have gained relevance for their light-weight combined with a high value of strength-to-weight ratio,which makes them useful in fields such as aerospace,automotive as well as biomedical engineering.Unfortunately,the poor corrosion resistance of Mg-alloys limits their wide acceptance.Advanced composite coatings which are self-healing,superhydrophobic anti corrosive,and wear resistant are new synthetic materials for abating these challenges.The superimposed superhydrophobic surfaces help in minimizing their water contact,thus slowing down the electrochemical reactions on the surface of the alloys,while their self-healing characteristics autonomously aid in the repair of any induced micro-crack,defect or damage towards ensuring the metal's long-term protection.In addition,the integration of wear-resistant materials further improves the durability of coatings under mechanical stress.The most recent research efforts have been directed towards the preparation of multifunctional composites,with an emphasis on nanomaterials,functional polymers,and state-of-the-art fabrication techniques in order to take advantage of their synergistic effects.Some of the methods that have so far exhibited promising potentials in fabricating these materials include the sol-gel method,layer-by-layer assembly,and plasma treatments.However,most of the fabricated products are still faced with significant challenges ranging from long-term stability to homogeneous adhesion of the coatings and their scalability for industrial applications.This review discusses the recent progress and the relationship between corrosion inhibition and self-healing efficiencies of wear resistant polymer nanocomposite coatings.Some challenges related to optimizing coating performance were also discussed.In addition,future directions ranging from the consideration of bioinspired designs,novel hybrid nanocomposite materials,and environmentally sustainable solutions integrated with smart protective coatings were also proposed as new wave technologies that can potentially revolutionize the corrosion protection offered by Mg alloys while opening up prospects for improved performance and sustainability.展开更多
Superhydrophobic surface is a promising strategy for antibacterial and corrosion protection.However,the use of harmful fluorine-containing materials,poor mechano-chemical stability,the addition of fungicides and poor ...Superhydrophobic surface is a promising strategy for antibacterial and corrosion protection.However,the use of harmful fluorine-containing materials,poor mechano-chemical stability,the addition of fungicides and poor corrosion resistance often limit its practical application.In this paper,a high-robustness pho-tothermal self-healing superhydrophobic coating is prepared by simply spraying a mixture of hydropho-bically modified epoxy resin and two kinds of modified nanofillers(carbon nanotubes and SiO2)for long-term anticorrosion and antibacterial applications.Multi-scale network and lubrication structures formed by cross-linking of modified carbon nanotubes and repeatable roughness endow coating with high ro-bustness,so that the coating maintains superhydrophobicity even after 100 Taber abrasion cycles,20 m sandpaper abrasion and 100 tape peeling cycles.The synergistic effect of antibacterial adhesion and pho-tothermal bactericidal activity endows coating with excellent antibacterial efficiency,which against Es-cherichia coli(E.coli)and Staphylococcus aureus(S.aureus)separately reaches 99.6% and 99.8%.Moreover,the influence of modified epoxy resin,superhydrophobicity,organic coating and coating thicknesses on the anticorrosion of magnesium(Mg)alloy is systematically studied and analyzed.More importantly,the prepared coating still exhibits excellent self-cleaning,anticorrosion and antibacterial abilities after 20 m abrasion.Furthermore,the coating exhibits excellent adhesion(level 4B),chemical stability,UV radiation resistance,high-low temperature alternation resistance,stable heat production capacity and photother-mal self-healing ability.All these excellent performances can promote its application in a wider range of fields.展开更多
Coatings of marine equipment inevitably suffer from physical or chemical damage in service,together with biofouling from microbial attachment,leading to a shorter service life of them.Herein,a multi-functional corrosi...Coatings of marine equipment inevitably suffer from physical or chemical damage in service,together with biofouling from microbial attachment,leading to a shorter service life of them.Herein,a multi-functional corrosion-resistant coating with efficient photothermal self-healing and anti-biofouling per-formance was designed by using CuO/g-C_(3)N_(4)(CuO/CN)S-scheme heterojunction filler in combination with polydimethylsiloxane(PDMS)as the coating matrix for achieving the effective protection of Q235 steel.The results of the electrochemical impedance spectroscopy(EIS)experiments indicate that the CuO/CN/PDMS composite coatings possessed excellent corrosion resistance,in which the impedance ra-dius of optimal CuO/CN-1/PDMS composite coating could still remain 3.49×10^(9)Ωcm^(2)after 60 d of immersion in seawater under sunlight irradiation.Meanwhile,the as-prepared CuO/CN/PDMS compos-ite coating not only can be rapidly heated up under the Xenon lamp illumination to achieve complete self-repair of scratches within 45 min,but also exhibited excellent antimicrobial effects in the antifouling experiments.This study opens a new avenue for the development of g-C_(3)N_(4)-based multifunctional coat-ings and provides guidance for the development of the next generation of intelligent protective coatings.展开更多
Drug-eluting magnesium(Mg)alloy stents have a slower degradation rate and lower restenosis rate compared with uncoated stents,demonstrating good clinical efficacy.However,the release of anti-hyperplasia drugs from coa...Drug-eluting magnesium(Mg)alloy stents have a slower degradation rate and lower restenosis rate compared with uncoated stents,demonstrating good clinical efficacy.However,the release of anti-hyperplasia drugs from coatings delays endothelial tissue repair,thus leading to late stent thrombosis.To address these issues,a dual self-healed coating with various biological properties was fabricated on magnesium fluoride/polydopamine(MgF_(2)/PDA)-treated Mg alloys by spraying-assisted layer-by-layer(LBL)self-assembly of chitosan(CS),gallic acid(GA),and 3-aminobenzeneboronic acid-modified hyaluronic acid(HA-ABBA).The LBL coating,approximately 1.50μm thick,exhibited a uniform morphology with good adhesion strength(~1065 mN).The annual corrosion rate(Pi)of LBL samples was~1400 times slower than that of the Mg substrate,due to the physical barrier function provided by MgF_(2)/PDA layers and the dual self-healed ability of LBL layers.The rapid self-healing ability(with a healing period of~4 h under dynamic/static conditions)resulted from the synergistic interplay between the recombination of diverse chemical bonds within the LBL coating and the coordination of LBL-released GA with Mg2+,as corroborated by computer simulations.Compared with the drug-eluting coatings,the LBL sample demonstrated substantial advantages in anti-oxidation,anti-denaturation of fibrinogen,anti-platelet adhesion,anti-inflammation,anti-hyperplasia,and promoted-endothelialization.These benefits effectively address the limitations associated with drug-eluting coatings.展开更多
This study investigates the mechanism of action of representative molecules of basalt fibers on the healing of water-soaked asphalt.Thermodynamic parameters,morphological characteristics,interfacial healing energy,and...This study investigates the mechanism of action of representative molecules of basalt fibers on the healing of water-soaked asphalt.Thermodynamic parameters,morphological characteristics,interfacial healing energy,and interfacial healing strength were analyzed using molecular dynamics and macroscopic tests under different time,temperature,and water conditions to evaluate the specific states and critical conditions involved in self-healing.The results indicate that basalt-fiber molecules can induce rearrangement and a combination of water-soaked asphalt at the healing interface.Hydroxyl groups with different bonding states increase the interfacial adsorption capacity of water-soaked asphalt.The interaction between basalt fiber molecules and water molecules leads to a"hoop"phenomenon,while aromatics-2 molecules exhibit a"ring band aggregation"phenomenon.The former reduces the miscibility of water and asphalt molecules,while the latter causes slow diffusion of the components.Furthermore,a micro-macro dual-scale comparison of interfacial healing strength was conducted at temperatures of 297.15 and 312.15 K to identify the strength transition point and critical temperature of 299.4 K during the self-healing process of basalt-fiber modified water-soaked asphalt.展开更多
Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,gr...Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,graphene oxide modified asphalt was prepared and characteristics was studied including the high deformation resistance performance and the self-healing property of modified asphalt.Functional groups and morphology of graphene oxide modified asphalt were described by Fourier transform infrared spectroscopy.The high deformation resistance performance and self-healing effect of asphalt samples were obtained through dynamic slear rheometer(DSR)test.Results shows that graphene oxide dispersions improve the performance of asphalt relatively well compared to graphene oxide powder.There is no chemical reaction between graphene oxide and asphalt,but physical connection.The addition of graphene oxide improved the high deformation resistance of modified asphalt and expedited the self-healing ability of asphalt under fatigue load.展开更多
Self-healing(SH)polymer composites are a transformative achievement in polymer material technology that offers significant potential to extend the lifespan and reliability of materials.This work presents a novel appro...Self-healing(SH)polymer composites are a transformative achievement in polymer material technology that offers significant potential to extend the lifespan and reliability of materials.This work presents a novel approach to developing a hybrid natural-synthetic reinforced polymer composite with SH behavior using urea-free,non-toxic,environment-friendly material encapsulating resin,and hardener within a multicavity microcapsule(MC).This MC offers multiple healing because of its multicavity structure.These Xerogel MCs are integrated into hybrid bamboo/recycled glass fiber reinforced epoxy composite(25 wt% and 40 wt%)and were evaluated for their flexural strength,healing efficiency,moisture absorption,and thermal behavior.The results demonstrated that the composite containing 40 wt% exhibited the highest initial flexural strength and modulus retention after multiple healing cycles,approaching 80.67% and 61.34% respectively at 1st and 2nd cycles of healing efficiency.The behavior of self-healing hybrid composites(SHHC)in different environmental conditions was also investigated.Thermal Analysis TGA and DTA done on hybrid and other SH composites.Scanning electron microscopy shows the surface morphology of Xerogel MCs before and after damage,composite fractured surface,and how Healing Agent(HA)gets released and acquires surface after fracture.To ensure functional groups and chemical reactions between each component of the composite,FTIR analysis confirmed the successful encapsulation of HA inside MC.展开更多
As a significant branch of smart materials,self-healing polyurethane materials mimic the biological damage repair mechanisms and have been widely applied in flexible electronics,functional coatings,biomedicine,and oth...As a significant branch of smart materials,self-healing polyurethane materials mimic the biological damage repair mechanisms and have been widely applied in flexible electronics,functional coatings,biomedicine,and other fields.This review systematically summarizes the design principles and recent advancements in both extrinsic and intrinsic self-healing polyurethane materials,highlighting their respective self-healing mechanisms and characteristics.For extrinsic system,damage repair is primarily achieved through microcapsules,hollow fibers,nanoparticles,and microvascular networks.However,their healing efficiency remains limited by the stability of carriers and the release kinetics of healing agents.In contrast,intrinsic self-healing polyurethane materials achieve self-healing through the reversibility of dynamic covalent and non-covalent bonds,which confer excellent self-healing capabilities while necessitating a precise balance between mechanical performance and self-healing efficiency.Moreover,their healing behavior is highly dependent on environmental conditions,potentially restricting their practical applications.Recent studies have demonstrated that the synergistic design of dynamic bonding networks can significantly enhance the mechanical properties,self-healing efficiency,and environmental adaptability.These developments offer new insights and theoretical foundations for designing high-performance self-healing polyurethane materials and may broaden their industrial applications.展开更多
Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that ...Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.展开更多
A two-step approach was employed to create a composite coating consisting of TiO_(2)nanoparticles and extremely elastic polydimethylsiloxane(PDMS).The TiO_(2)-PDMS composite coating demonstrates exceptional superhydro...A two-step approach was employed to create a composite coating consisting of TiO_(2)nanoparticles and extremely elastic polydimethylsiloxane(PDMS).The TiO_(2)-PDMS composite coating demonstrates exceptional superhydrophobicity and antifouling efficacy,as evidenced by the static contact angle,contact angle hysteresis,and antifouling tests.The electron microscopic analysis reveals that the composite coating consists of TiO_(2)particles and agglomerates,which forms a dual-level roughness structure at the nanometer and micron scales.This unique structure promotes the Cassie-Baxter state of the coating when in contact with the liquid,resulting in an increased static contact angle and a reduced contact angle hysteresis.The PDMS primer facilitates the attachment of TiO_(2)particles,resulting in a composite coating with excellent scratch-resistant characteristics.Additionally,the PDMS primer possesses the capacity to retain low surface energy modifiers.Simultaneously,the PDMS primer serves as a reservoir for a low surface energy modifier,enhancing the self-repairing properties of the TiO_(2)-PDMS composite coating.This composite coating exhibits effective self-cleaning capabilities against many forms of contaminants,including liquids,solids,and slurries.展开更多
Traditional hydrogels are inevitably damaged during practical applications,resulting in a gradual deterioration of their functional efficacy.A primary strategy to address this issue involves developing hydrogels with ...Traditional hydrogels are inevitably damaged during practical applications,resulting in a gradual deterioration of their functional efficacy.A primary strategy to address this issue involves developing hydrogels with inherent self-healing properties.In this study,we report the synthesis of self-healing polyacrylate hydrogels that integrate zwitterions,hydrophilic nano-silica and aluminum ions.Due to the synergistic effect of multiple hydrogen bonds,coordination bonds and electrostatic interactions,the tensile strength of the hydrogel is enhanced from 15.1 to 162.6 kPa.Moreover,the electrical resistance and tensile strength of the hydrogel can almost recover to its initial values after 20 min of healing at room temperature,exhibiting remarkable self-healing performance.Furthermore,the zwitterionic polyacrylate hydrogel serves as a wearable sensor with the capability of accurately response to the bending and stretching of human joints,exhibting a gauge factor of 1.87 under tensile strain ranging from 80% to 100%.Even after being freezed at-20℃ for 3 h,the zwitterionic polyacrylate hydrogel retains its exceptional writing performance.In conclusion,the hydrogels developed in this study demonstrate significant potential for wearable electronics applications.展开更多
Integrated conductive elastomers with excellent mechanical performance,stable high conductivity,self-healing capabilities,and high transparency are critical for advancing wearable devices.Nevertheless,achieving an opt...Integrated conductive elastomers with excellent mechanical performance,stable high conductivity,self-healing capabilities,and high transparency are critical for advancing wearable devices.Nevertheless,achieving an optimal balance among these properties remains a significant challenge.Herein,through in situ free-radical copolymerization of 2-[2-(2-methoxyethoxy)ethoxy]ethyl acrylate(TEEA)and vinylimidazole(VI)in the presence of polyethylene glycol(PEG;Mn=400),tough P(TEEA-co-VI)/PEG elastomers with multiple functionalities were prepared,in which P(TEEA-co-VI)was dynamically cross-linked by imidazole-Zn^(2+)metal coordination crosslinks,and physically blended with PEG as polymer electrolyte to form a homogeneous mixture.Notably,Zn^(2+)has a negligible impact on the polymerization process,allowing for the in situ formation of numerous imidazole-Zn^(2+)metal coordination crosslinks,which can effectively dissipate energy upon stretching to largely reinforce the elastomers.The obtained P(TEEA-co-VI)/PEG elastomers exhibited a high toughness of 10.0 MJ·m^(-3) with a high tensile strength of 3.3 MPa and a large elongation at break of 645%,along with outstanding self-healing capabilities due to the dynamic coordination crosslinks.Moreover,because of the miscibility of PEG with PTEEA copolymer matrix,and Li+can form weak coordination interactions with the ethoxy(EO)units in PEG and PTEEA,acting as a bridge to integrate PEG into the elastomer network.The resulted P(TEEA-co-VI)/PEG elastomers showed high transparency(92%)and stable high conductivity of 1.09×10_(-4) S·cm^(-1).In summary,the obtained elastomers exhibited a well-balanced combination of high toughness,high ionic conductivity,excellent self-healing capabilities,and high transparency,making them promising for applications in flexible strain sensors.展开更多
Soft self-healing materials are promising candidates for flexible electronic devices due to their excep-tional compatibility,extensibility,and self-restorability.Generally,these materials suffer from low tensile stren...Soft self-healing materials are promising candidates for flexible electronic devices due to their excep-tional compatibility,extensibility,and self-restorability.Generally,these materials suffer from low tensile strength and susceptibility to fracture because of the restricted microstructure design.Herein,we pro-pose a hydrothermal-freeze-thaw method to construct high-strength self-healing hydrogels with even in-terconnected networks and distinctive wrinkled surfaces.The integration of the wrinkled outer surface with the three-dimensional internal network confers the self-healing hydrogel with enhanced mechan-ical strength.This hydrogel achieves a tensile strength of 223 kPa,a breaking elongation of 442%,an adhesion strength of 57.6 kPa,and an adhesion energy of 237.2 J m-2.Meanwhile,the hydrogel demon-strates impressive self-repair capability(repair efficiency:93%).Moreover,the density functional theory(DFT)calculations are used to substantiate the stable existence of hydrogen bonding between the PPPBG hydrogel and water molecules which ensures the durability of the PPPBG hydrogel for long-term applica-tion.The measurements demonstrate that this multifunctional hydrogel possesses the requisite sensitivity and durability to serve as a strain sensor,which monitors a spectrum of motion signals including subtle vocalizations,pronounced facial expressions,and limb articulations.This work presents a viable strategy for healthcare monitoring,soft robotics,and interactive electronic skins.展开更多
Supramolecular materials that combine toughness,transparency,self-healing,and environmental stability are crucial for advanced applications,such as flexible electronics,wearable devices,and protective coatings.However...Supramolecular materials that combine toughness,transparency,self-healing,and environmental stability are crucial for advanced applications,such as flexible electronics,wearable devices,and protective coatings.However,integrating these properties into a single system remains challenging because of the inherent trade-offs between the mechanical strength,elasticity,and structural reconfigurability.Herein,we report a supramolecular ionogel designed via a simple one-step polymerization strategy that combines hydrogen bonding and ion-dipole interactions in a physically crosslinked network.This dual-interaction architecture enables the ionogel to achieve high tensile strength(9 MPa),remarkable fracture toughness(23.6 MJ·m^(−3)),and rapid self-healing under mild thermal stimulation.The material remains highly transparent and demonstrates excellent resistance to moisture,acid,and salt environments,with minimal swelling and performance degradation.Furthermore,it effectively dissipates over 80 MJ·m^(−3) of energy during high-speed impacts,providing reliable protection to fragile substrates.This study offers a broadly applicable molecular design framework for resilient and adaptive soft materials.展开更多
To enhance the corrosion resistance of Mg-Li alloy,a composite coating system integrating plasma electrolytic oxidation(PEO)with solgel sealing treatment is developed.Two functionalized sepiolite microcontainers(sepio...To enhance the corrosion resistance of Mg-Li alloy,a composite coating system integrating plasma electrolytic oxidation(PEO)with solgel sealing treatment is developed.Two functionalized sepiolite microcontainers(sepiolite-Ce and sepiolite-BA)are constructed by loading cerium ions(Ce3+)via ion exchange and encapsulating barbituric acid(BA)through low-pressure impregnation.The microcontainers are subsequently incorporated into the coating surface through controlled sol-gel deposition process.UV-Vis and ICP-OES analyses reveal that both functionalized sepiolite microcontainers exhibited pH-responsive release characteristics under alkaline conditions.Electrochemical impedance spectroscopy(EIS)tests demonstrate that the inhibitor-containing composite coating has excellent long-term corrosion resistance and self-healing performance.After 240 h of immersion in a 0.5 wt.%NaCl solution,the low-frequency impedance modulus of the composite coating is four orders of magnitude higher than that of the pristine coating.展开更多
The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials(ECMs).However,the currently prepared ECMs with self-heali...The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials(ECMs).However,the currently prepared ECMs with self-healing function have problems such as irregular particle shape and uneven distribution of components,which affect the efficient play of self-healing function.In this paper,HMX-based energetic microspheres with self-healing function were successfully prepared by microchannel technology,which showed excellent self-healing effect in both Polymer-bonded explosives(PBXs)and Composite solid propellants(CSPs).The experimental results show that the HMX-based energetic microspheres with different binder contents prepared by microchannel technology show regular shape,HMX crystal particles are uniformly wrapped by self-healing binder(GAPU).When the content of GAPU in HMX-based energetic microspheres is 10%,PBXs show excellent self-healing effect and mechanical safety is improved by 400%(raw HMX vs S4,5 J vs 25 J).As a high-energy component,the burning rate of CSPs is increased by 359.4%,the time(burning temperature>1700℃)is prolonged by 333.3%,and the maximum impulse force is increased by 107.3%(CSP-H vs CSP-S4,0.84 mm/s vs 3.87 mm/s,0.06 s vs 0.26 s,0.82 m N vs 1.70 m N).It also has excellent storage performance.The preparation of HMX-based energetic microspheres with self-healing function by microchannel technology provides a new strategy to improve the storage performance of ECMs and the combustion performance of CSPs.展开更多
The self-healing properties of dual-component epoxy microcapsules are evaluated when incorporated into an epoxy coating.The performance of the coating was assessed under immersion in a saline solution,simulating seawa...The self-healing properties of dual-component epoxy microcapsules are evaluated when incorporated into an epoxy coating.The performance of the coating was assessed under immersion in a saline solution,simulating seawater conditions.Initially,synthesized microcapsules are incorporated into the epoxy coating.Then,the self-healing capabilities of the coating are studied under immersion using scanning vibrating electrode technique(SVET),open circuit potential(OCP),electrochemical impedance spectroscopy(EIS)and immersion corrosion test on coated samples with intentionally created artificial defects.The last three tests were conducted in a 3.5%NaCl solution.The adhesion of the coating is also studied by pull-off adhesion test.SVET analyses reveal lower ionic current densities in coated samples containing microcapsules during 24 h of immersion.EIS results demonstrate self-healing at the defect site for up to 12 h of immersion.After this time,the corrosion protection diminishes with prolonged immersion in the saline solution.Despite this,the coating with the microcapsules exhibits decrease in the corrosion process compared to the coating without the microcapsules.These results are consistent and complement the outcomes of the immersion tests conducted over 360 and 1056 h,which indicate that coated samples without microcapsules exhibit double the corroded areas around the scribes compared to coated samples containing the microcapsules.These findings offer a promising outlook for applying this coating on offshore carbon steel structures under immersion aiming for a longer lifetime with less maintenance intervention.展开更多
To address the inherent trade-off between mechanical strength and repair efficiency in conventional microcapsule-based self-healing technologies,this study presents an eggshell-inspired approach for fabricating high-l...To address the inherent trade-off between mechanical strength and repair efficiency in conventional microcapsule-based self-healing technologies,this study presents an eggshell-inspired approach for fabricating high-load rigid porous microcapsules(HLRPMs)through subcritical water etching.By optimizing the subcritical water treatment parameters(OH−concentration:0.031 mol/L,tem-perature:240°C,duration:1.5 h),nanoscale through-holes were generated on hollow glass microspheres(shell thickness≈700 nm).The subsequent gradient pressure infiltration of flaxseed oil enabled a record-high core content of 88.2%.Systematic investigations demonstrated that incorporating 3 wt%HLRPMs into epoxy resin composites preserved excellent dielectric properties(breakdown strength≥30 kV/mm)and enhanced tensile strength by 7.52%.In addressing multimodal damage,the system achieved a 95.5%filling efficiency for mechanical scratches,a 97.0%reduction in frictional damage depth,and a 96.2%recovery of insulation following electrical treeing.This biomimetic microcapsule system concurrently improved self-healing capability and matrix performance,offering a promising strategy for the development of next-generation smart insulating materials.展开更多
An evaluation method for self-healing capacity was designed,which includes the control of initial cracks and subsequent permeability testing.This method was employed to evaluate the self-healing behavior of mortars in...An evaluation method for self-healing capacity was designed,which includes the control of initial cracks and subsequent permeability testing.This method was employed to evaluate the self-healing behavior of mortars incorporating crystalline admixtures(CAs)under various conditions,including water immersion,limewater soaking,and wet-dry cycles,with varying CA dosages and crack widths.The experimental results indicate that cement possesses inherently self-healing capability.Limewater environments inhibits healing compared with water immersion;however,wet-dry cycles enhance the effectiveness of higher CA dosages.Increasing the CA content can not improve healing performance,and wide cracks(0.3 mm)substantially reduce the intrinsic self-healing potential of cement.展开更多
基金the National Natural Science Foundation of China(Nos.52033011,51873235 and 51973237)Natural Science Foundation of Guangdong Province,China(Nos.2019B1515120038 and 2021A1515010417)+1 种基金Science and Technology Planning Project of Guangdong Province(No.2020B010179001)Industry-University-Research Collaboration Project of Zhuhai City(No.ZH22017001200004PWC).
文摘To construct structurally stable sulfur cathode of Li-S battery with improved cycling performance,poly(acrylic acid)(PAA)crosslinked by cationic hydroxypropyl polyrotaxane(HPRN+)via dynamically reversible boronic ester bonds is synthesized and serves as the cathode binder.The smart polymer networks offer multifunction including buffering the volume change of the cathode during charge/discharge through the pulley effect of polyrotaxanes(PR),suppressing the shuttle effect by adsorption of polysulfide using the plentiful carboxyl,hydroxyl and quaternary ammonium cationic groups,and self-healing the micro-damages to ensure stable conduction pathways of the electrode.As a result,the Li-S batteries based on this novel multifunctional binder and simple commercial sulfur/carbon composites cathode exhibit excellent specific capacity and cycling stability.In particular,the specific capacity decay per cycle of the cell is only 0.064%along with high Coulombic efficiency after 550 cycles at 1.0 C,which is superior to most of the reported binders.Even under high sulfur loading,moreover,the cathode can deliver superior areal capacity and cycling stability.This proposed binder provides a new way for the design of high-stability sulfur cathodes.
文摘Magnesium and its alloys have gained relevance for their light-weight combined with a high value of strength-to-weight ratio,which makes them useful in fields such as aerospace,automotive as well as biomedical engineering.Unfortunately,the poor corrosion resistance of Mg-alloys limits their wide acceptance.Advanced composite coatings which are self-healing,superhydrophobic anti corrosive,and wear resistant are new synthetic materials for abating these challenges.The superimposed superhydrophobic surfaces help in minimizing their water contact,thus slowing down the electrochemical reactions on the surface of the alloys,while their self-healing characteristics autonomously aid in the repair of any induced micro-crack,defect or damage towards ensuring the metal's long-term protection.In addition,the integration of wear-resistant materials further improves the durability of coatings under mechanical stress.The most recent research efforts have been directed towards the preparation of multifunctional composites,with an emphasis on nanomaterials,functional polymers,and state-of-the-art fabrication techniques in order to take advantage of their synergistic effects.Some of the methods that have so far exhibited promising potentials in fabricating these materials include the sol-gel method,layer-by-layer assembly,and plasma treatments.However,most of the fabricated products are still faced with significant challenges ranging from long-term stability to homogeneous adhesion of the coatings and their scalability for industrial applications.This review discusses the recent progress and the relationship between corrosion inhibition and self-healing efficiencies of wear resistant polymer nanocomposite coatings.Some challenges related to optimizing coating performance were also discussed.In addition,future directions ranging from the consideration of bioinspired designs,novel hybrid nanocomposite materials,and environmentally sustainable solutions integrated with smart protective coatings were also proposed as new wave technologies that can potentially revolutionize the corrosion protection offered by Mg alloys while opening up prospects for improved performance and sustainability.
基金the National Natural Science Foundation of China(Nos.U2106226,52105297)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)the Science and Technology Development Project of Jilin Province(Nos.20210203022SF,20210508029RQ).
文摘Superhydrophobic surface is a promising strategy for antibacterial and corrosion protection.However,the use of harmful fluorine-containing materials,poor mechano-chemical stability,the addition of fungicides and poor corrosion resistance often limit its practical application.In this paper,a high-robustness pho-tothermal self-healing superhydrophobic coating is prepared by simply spraying a mixture of hydropho-bically modified epoxy resin and two kinds of modified nanofillers(carbon nanotubes and SiO2)for long-term anticorrosion and antibacterial applications.Multi-scale network and lubrication structures formed by cross-linking of modified carbon nanotubes and repeatable roughness endow coating with high ro-bustness,so that the coating maintains superhydrophobicity even after 100 Taber abrasion cycles,20 m sandpaper abrasion and 100 tape peeling cycles.The synergistic effect of antibacterial adhesion and pho-tothermal bactericidal activity endows coating with excellent antibacterial efficiency,which against Es-cherichia coli(E.coli)and Staphylococcus aureus(S.aureus)separately reaches 99.6% and 99.8%.Moreover,the influence of modified epoxy resin,superhydrophobicity,organic coating and coating thicknesses on the anticorrosion of magnesium(Mg)alloy is systematically studied and analyzed.More importantly,the prepared coating still exhibits excellent self-cleaning,anticorrosion and antibacterial abilities after 20 m abrasion.Furthermore,the coating exhibits excellent adhesion(level 4B),chemical stability,UV radiation resistance,high-low temperature alternation resistance,stable heat production capacity and photother-mal self-healing ability.All these excellent performances can promote its application in a wider range of fields.
基金supported by the National Natural Science Foundation of China(Nos.22006057 and 21906072)the China Postdoctoral Science Foundation(No.2023M743178)+2 种基金the Jiangsu Province Industry-University-Research Cooperation Project(No.BY20231482)the Open Fund of the Key Laboratory of Solar Cell electrode Materials in China Petroleum,Chemical Industry(No.2024A093)the Key Laboratory of Functional Inorganic Mate-rial Chemistry(Heilongjiang University),Ministry of Education and Postgraduate Research&Practice Innovation Program of Jiangsu Province(China)(No.SJCX24_2481).
文摘Coatings of marine equipment inevitably suffer from physical or chemical damage in service,together with biofouling from microbial attachment,leading to a shorter service life of them.Herein,a multi-functional corrosion-resistant coating with efficient photothermal self-healing and anti-biofouling per-formance was designed by using CuO/g-C_(3)N_(4)(CuO/CN)S-scheme heterojunction filler in combination with polydimethylsiloxane(PDMS)as the coating matrix for achieving the effective protection of Q235 steel.The results of the electrochemical impedance spectroscopy(EIS)experiments indicate that the CuO/CN/PDMS composite coatings possessed excellent corrosion resistance,in which the impedance ra-dius of optimal CuO/CN-1/PDMS composite coating could still remain 3.49×10^(9)Ωcm^(2)after 60 d of immersion in seawater under sunlight irradiation.Meanwhile,the as-prepared CuO/CN/PDMS compos-ite coating not only can be rapidly heated up under the Xenon lamp illumination to achieve complete self-repair of scratches within 45 min,but also exhibited excellent antimicrobial effects in the antifouling experiments.This study opens a new avenue for the development of g-C_(3)N_(4)-based multifunctional coat-ings and provides guidance for the development of the next generation of intelligent protective coatings.
基金supported by the National Key Research and Development Program of China(No.2021YFC2400703)the Key Scientific and Technological Research Projects in Henan Province(Nos.232102311155 and 232102230106)Zhengzhou University Major Project Cultivation Special Project(No.125-32214076).
文摘Drug-eluting magnesium(Mg)alloy stents have a slower degradation rate and lower restenosis rate compared with uncoated stents,demonstrating good clinical efficacy.However,the release of anti-hyperplasia drugs from coatings delays endothelial tissue repair,thus leading to late stent thrombosis.To address these issues,a dual self-healed coating with various biological properties was fabricated on magnesium fluoride/polydopamine(MgF_(2)/PDA)-treated Mg alloys by spraying-assisted layer-by-layer(LBL)self-assembly of chitosan(CS),gallic acid(GA),and 3-aminobenzeneboronic acid-modified hyaluronic acid(HA-ABBA).The LBL coating,approximately 1.50μm thick,exhibited a uniform morphology with good adhesion strength(~1065 mN).The annual corrosion rate(Pi)of LBL samples was~1400 times slower than that of the Mg substrate,due to the physical barrier function provided by MgF_(2)/PDA layers and the dual self-healed ability of LBL layers.The rapid self-healing ability(with a healing period of~4 h under dynamic/static conditions)resulted from the synergistic interplay between the recombination of diverse chemical bonds within the LBL coating and the coordination of LBL-released GA with Mg2+,as corroborated by computer simulations.Compared with the drug-eluting coatings,the LBL sample demonstrated substantial advantages in anti-oxidation,anti-denaturation of fibrinogen,anti-platelet adhesion,anti-inflammation,anti-hyperplasia,and promoted-endothelialization.These benefits effectively address the limitations associated with drug-eluting coatings.
文摘This study investigates the mechanism of action of representative molecules of basalt fibers on the healing of water-soaked asphalt.Thermodynamic parameters,morphological characteristics,interfacial healing energy,and interfacial healing strength were analyzed using molecular dynamics and macroscopic tests under different time,temperature,and water conditions to evaluate the specific states and critical conditions involved in self-healing.The results indicate that basalt-fiber molecules can induce rearrangement and a combination of water-soaked asphalt at the healing interface.Hydroxyl groups with different bonding states increase the interfacial adsorption capacity of water-soaked asphalt.The interaction between basalt fiber molecules and water molecules leads to a"hoop"phenomenon,while aromatics-2 molecules exhibit a"ring band aggregation"phenomenon.The former reduces the miscibility of water and asphalt molecules,while the latter causes slow diffusion of the components.Furthermore,a micro-macro dual-scale comparison of interfacial healing strength was conducted at temperatures of 297.15 and 312.15 K to identify the strength transition point and critical temperature of 299.4 K during the self-healing process of basalt-fiber modified water-soaked asphalt.
基金supported by Gansu Provincial Science and Technology Plan(23CXGA0195)Longnan Science and Technology Plan(2024CX03)。
文摘Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,graphene oxide modified asphalt was prepared and characteristics was studied including the high deformation resistance performance and the self-healing property of modified asphalt.Functional groups and morphology of graphene oxide modified asphalt were described by Fourier transform infrared spectroscopy.The high deformation resistance performance and self-healing effect of asphalt samples were obtained through dynamic slear rheometer(DSR)test.Results shows that graphene oxide dispersions improve the performance of asphalt relatively well compared to graphene oxide powder.There is no chemical reaction between graphene oxide and asphalt,but physical connection.The addition of graphene oxide improved the high deformation resistance of modified asphalt and expedited the self-healing ability of asphalt under fatigue load.
文摘Self-healing(SH)polymer composites are a transformative achievement in polymer material technology that offers significant potential to extend the lifespan and reliability of materials.This work presents a novel approach to developing a hybrid natural-synthetic reinforced polymer composite with SH behavior using urea-free,non-toxic,environment-friendly material encapsulating resin,and hardener within a multicavity microcapsule(MC).This MC offers multiple healing because of its multicavity structure.These Xerogel MCs are integrated into hybrid bamboo/recycled glass fiber reinforced epoxy composite(25 wt% and 40 wt%)and were evaluated for their flexural strength,healing efficiency,moisture absorption,and thermal behavior.The results demonstrated that the composite containing 40 wt% exhibited the highest initial flexural strength and modulus retention after multiple healing cycles,approaching 80.67% and 61.34% respectively at 1st and 2nd cycles of healing efficiency.The behavior of self-healing hybrid composites(SHHC)in different environmental conditions was also investigated.Thermal Analysis TGA and DTA done on hybrid and other SH composites.Scanning electron microscopy shows the surface morphology of Xerogel MCs before and after damage,composite fractured surface,and how Healing Agent(HA)gets released and acquires surface after fracture.To ensure functional groups and chemical reactions between each component of the composite,FTIR analysis confirmed the successful encapsulation of HA inside MC.
基金sponsored by the National Key Research and Devel-opment Program of China(2023YFD1800105)Guangdong Province Science&Technology Program(2024B1515040004)Guangzhou Sci-ence and Technology Plan Project(2024A04J6354).
文摘As a significant branch of smart materials,self-healing polyurethane materials mimic the biological damage repair mechanisms and have been widely applied in flexible electronics,functional coatings,biomedicine,and other fields.This review systematically summarizes the design principles and recent advancements in both extrinsic and intrinsic self-healing polyurethane materials,highlighting their respective self-healing mechanisms and characteristics.For extrinsic system,damage repair is primarily achieved through microcapsules,hollow fibers,nanoparticles,and microvascular networks.However,their healing efficiency remains limited by the stability of carriers and the release kinetics of healing agents.In contrast,intrinsic self-healing polyurethane materials achieve self-healing through the reversibility of dynamic covalent and non-covalent bonds,which confer excellent self-healing capabilities while necessitating a precise balance between mechanical performance and self-healing efficiency.Moreover,their healing behavior is highly dependent on environmental conditions,potentially restricting their practical applications.Recent studies have demonstrated that the synergistic design of dynamic bonding networks can significantly enhance the mechanical properties,self-healing efficiency,and environmental adaptability.These developments offer new insights and theoretical foundations for designing high-performance self-healing polyurethane materials and may broaden their industrial applications.
基金supported by the National Natural Science Foundation of China(Nos.51973025 and 52222307)Jilin Science and Technology Bureau(Nos.20220204107YY and 20230204086YY)+1 种基金Changchun Science and Technology Bureau(No.21ZGY06)Jilin Province Development and Reform Commission(No.2023C028-4).
文摘Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.
基金Funded by the National Science and Technology Major Project(No.J2019-VII-0015-0155)the National Natural Science Foundation of China(No.51705533)。
文摘A two-step approach was employed to create a composite coating consisting of TiO_(2)nanoparticles and extremely elastic polydimethylsiloxane(PDMS).The TiO_(2)-PDMS composite coating demonstrates exceptional superhydrophobicity and antifouling efficacy,as evidenced by the static contact angle,contact angle hysteresis,and antifouling tests.The electron microscopic analysis reveals that the composite coating consists of TiO_(2)particles and agglomerates,which forms a dual-level roughness structure at the nanometer and micron scales.This unique structure promotes the Cassie-Baxter state of the coating when in contact with the liquid,resulting in an increased static contact angle and a reduced contact angle hysteresis.The PDMS primer facilitates the attachment of TiO_(2)particles,resulting in a composite coating with excellent scratch-resistant characteristics.Additionally,the PDMS primer possesses the capacity to retain low surface energy modifiers.Simultaneously,the PDMS primer serves as a reservoir for a low surface energy modifier,enhancing the self-repairing properties of the TiO_(2)-PDMS composite coating.This composite coating exhibits effective self-cleaning capabilities against many forms of contaminants,including liquids,solids,and slurries.
基金financially supported by the National Key Research and Development Program of China(2022YFE0138900)the National Natural Science Foundation of China(21972017)+1 种基金the Fundamental Research Funds for the Central Universities of Ministry of Education of China(D5000240188)the"Scientific and Technical Innovation Action Plan"Basic Research Field of Shanghai Science and Technology Committee(19JC1410500)。
文摘Traditional hydrogels are inevitably damaged during practical applications,resulting in a gradual deterioration of their functional efficacy.A primary strategy to address this issue involves developing hydrogels with inherent self-healing properties.In this study,we report the synthesis of self-healing polyacrylate hydrogels that integrate zwitterions,hydrophilic nano-silica and aluminum ions.Due to the synergistic effect of multiple hydrogen bonds,coordination bonds and electrostatic interactions,the tensile strength of the hydrogel is enhanced from 15.1 to 162.6 kPa.Moreover,the electrical resistance and tensile strength of the hydrogel can almost recover to its initial values after 20 min of healing at room temperature,exhibiting remarkable self-healing performance.Furthermore,the zwitterionic polyacrylate hydrogel serves as a wearable sensor with the capability of accurately response to the bending and stretching of human joints,exhibting a gauge factor of 1.87 under tensile strain ranging from 80% to 100%.Even after being freezed at-20℃ for 3 h,the zwitterionic polyacrylate hydrogel retains its exceptional writing performance.In conclusion,the hydrogels developed in this study demonstrate significant potential for wearable electronics applications.
基金supported by the National Natural Science Foundation of China(Nos.52273023,51973103,and 21774069).
文摘Integrated conductive elastomers with excellent mechanical performance,stable high conductivity,self-healing capabilities,and high transparency are critical for advancing wearable devices.Nevertheless,achieving an optimal balance among these properties remains a significant challenge.Herein,through in situ free-radical copolymerization of 2-[2-(2-methoxyethoxy)ethoxy]ethyl acrylate(TEEA)and vinylimidazole(VI)in the presence of polyethylene glycol(PEG;Mn=400),tough P(TEEA-co-VI)/PEG elastomers with multiple functionalities were prepared,in which P(TEEA-co-VI)was dynamically cross-linked by imidazole-Zn^(2+)metal coordination crosslinks,and physically blended with PEG as polymer electrolyte to form a homogeneous mixture.Notably,Zn^(2+)has a negligible impact on the polymerization process,allowing for the in situ formation of numerous imidazole-Zn^(2+)metal coordination crosslinks,which can effectively dissipate energy upon stretching to largely reinforce the elastomers.The obtained P(TEEA-co-VI)/PEG elastomers exhibited a high toughness of 10.0 MJ·m^(-3) with a high tensile strength of 3.3 MPa and a large elongation at break of 645%,along with outstanding self-healing capabilities due to the dynamic coordination crosslinks.Moreover,because of the miscibility of PEG with PTEEA copolymer matrix,and Li+can form weak coordination interactions with the ethoxy(EO)units in PEG and PTEEA,acting as a bridge to integrate PEG into the elastomer network.The resulted P(TEEA-co-VI)/PEG elastomers showed high transparency(92%)and stable high conductivity of 1.09×10_(-4) S·cm^(-1).In summary,the obtained elastomers exhibited a well-balanced combination of high toughness,high ionic conductivity,excellent self-healing capabilities,and high transparency,making them promising for applications in flexible strain sensors.
基金supported by the National Natural Science Foundation of China(Nos.U21A6004,U21A20172,61804091,21574076,and U1510121)the Science and Technology Major Project of Shanxi(No.202101030201022)+1 种基金the Fundamental Research Program of Shanxi Province(No.202103021223019)the Open Fund of the Key Lab of Organic Optoelectronics&Molecular Engineering.
文摘Soft self-healing materials are promising candidates for flexible electronic devices due to their excep-tional compatibility,extensibility,and self-restorability.Generally,these materials suffer from low tensile strength and susceptibility to fracture because of the restricted microstructure design.Herein,we pro-pose a hydrothermal-freeze-thaw method to construct high-strength self-healing hydrogels with even in-terconnected networks and distinctive wrinkled surfaces.The integration of the wrinkled outer surface with the three-dimensional internal network confers the self-healing hydrogel with enhanced mechan-ical strength.This hydrogel achieves a tensile strength of 223 kPa,a breaking elongation of 442%,an adhesion strength of 57.6 kPa,and an adhesion energy of 237.2 J m-2.Meanwhile,the hydrogel demon-strates impressive self-repair capability(repair efficiency:93%).Moreover,the density functional theory(DFT)calculations are used to substantiate the stable existence of hydrogen bonding between the PPPBG hydrogel and water molecules which ensures the durability of the PPPBG hydrogel for long-term applica-tion.The measurements demonstrate that this multifunctional hydrogel possesses the requisite sensitivity and durability to serve as a strain sensor,which monitors a spectrum of motion signals including subtle vocalizations,pronounced facial expressions,and limb articulations.This work presents a viable strategy for healthcare monitoring,soft robotics,and interactive electronic skins.
基金supported by the National Natural Science Foundation of China(Nos.T2222019 and T2225016)the National Key R&D Program of China(No.2024YFA0919300)the Fundamental Research Funds for the Central Universities(Nos.020414380232 and 021414380534).
文摘Supramolecular materials that combine toughness,transparency,self-healing,and environmental stability are crucial for advanced applications,such as flexible electronics,wearable devices,and protective coatings.However,integrating these properties into a single system remains challenging because of the inherent trade-offs between the mechanical strength,elasticity,and structural reconfigurability.Herein,we report a supramolecular ionogel designed via a simple one-step polymerization strategy that combines hydrogen bonding and ion-dipole interactions in a physically crosslinked network.This dual-interaction architecture enables the ionogel to achieve high tensile strength(9 MPa),remarkable fracture toughness(23.6 MJ·m^(−3)),and rapid self-healing under mild thermal stimulation.The material remains highly transparent and demonstrates excellent resistance to moisture,acid,and salt environments,with minimal swelling and performance degradation.Furthermore,it effectively dissipates over 80 MJ·m^(−3) of energy during high-speed impacts,providing reliable protection to fragile substrates.This study offers a broadly applicable molecular design framework for resilient and adaptive soft materials.
基金financially supported by LiaoNing Revitalization Talents Program(XLYC2403026)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(RC231178)the Fundamental Research Funds for the Central Universities(N25GFY002).
文摘To enhance the corrosion resistance of Mg-Li alloy,a composite coating system integrating plasma electrolytic oxidation(PEO)with solgel sealing treatment is developed.Two functionalized sepiolite microcontainers(sepiolite-Ce and sepiolite-BA)are constructed by loading cerium ions(Ce3+)via ion exchange and encapsulating barbituric acid(BA)through low-pressure impregnation.The microcontainers are subsequently incorporated into the coating surface through controlled sol-gel deposition process.UV-Vis and ICP-OES analyses reveal that both functionalized sepiolite microcontainers exhibited pH-responsive release characteristics under alkaline conditions.Electrochemical impedance spectroscopy(EIS)tests demonstrate that the inhibitor-containing composite coating has excellent long-term corrosion resistance and self-healing performance.After 240 h of immersion in a 0.5 wt.%NaCl solution,the low-frequency impedance modulus of the composite coating is four orders of magnitude higher than that of the pristine coating.
基金support given by the Fundamental Research Program of Shanxi Province(Grant No.202203021212152)。
文摘The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials(ECMs).However,the currently prepared ECMs with self-healing function have problems such as irregular particle shape and uneven distribution of components,which affect the efficient play of self-healing function.In this paper,HMX-based energetic microspheres with self-healing function were successfully prepared by microchannel technology,which showed excellent self-healing effect in both Polymer-bonded explosives(PBXs)and Composite solid propellants(CSPs).The experimental results show that the HMX-based energetic microspheres with different binder contents prepared by microchannel technology show regular shape,HMX crystal particles are uniformly wrapped by self-healing binder(GAPU).When the content of GAPU in HMX-based energetic microspheres is 10%,PBXs show excellent self-healing effect and mechanical safety is improved by 400%(raw HMX vs S4,5 J vs 25 J).As a high-energy component,the burning rate of CSPs is increased by 359.4%,the time(burning temperature>1700℃)is prolonged by 333.3%,and the maximum impulse force is increased by 107.3%(CSP-H vs CSP-S4,0.84 mm/s vs 3.87 mm/s,0.06 s vs 0.26 s,0.82 m N vs 1.70 m N).It also has excellent storage performance.The preparation of HMX-based energetic microspheres with self-healing function by microchannel technology provides a new strategy to improve the storage performance of ECMs and the combustion performance of CSPs.
基金supported by CAPES scholarship-Brazil Coordination for the Improvement of Higher Education Personnel(No.88887.507764/2020-00)]by CNPq-Brazil National Council of Technological and Scientific Development(No.308564/2023-5).
文摘The self-healing properties of dual-component epoxy microcapsules are evaluated when incorporated into an epoxy coating.The performance of the coating was assessed under immersion in a saline solution,simulating seawater conditions.Initially,synthesized microcapsules are incorporated into the epoxy coating.Then,the self-healing capabilities of the coating are studied under immersion using scanning vibrating electrode technique(SVET),open circuit potential(OCP),electrochemical impedance spectroscopy(EIS)and immersion corrosion test on coated samples with intentionally created artificial defects.The last three tests were conducted in a 3.5%NaCl solution.The adhesion of the coating is also studied by pull-off adhesion test.SVET analyses reveal lower ionic current densities in coated samples containing microcapsules during 24 h of immersion.EIS results demonstrate self-healing at the defect site for up to 12 h of immersion.After this time,the corrosion protection diminishes with prolonged immersion in the saline solution.Despite this,the coating with the microcapsules exhibits decrease in the corrosion process compared to the coating without the microcapsules.These results are consistent and complement the outcomes of the immersion tests conducted over 360 and 1056 h,which indicate that coated samples without microcapsules exhibit double the corroded areas around the scribes compared to coated samples containing the microcapsules.These findings offer a promising outlook for applying this coating on offshore carbon steel structures under immersion aiming for a longer lifetime with less maintenance intervention.
基金supported by the National Natural Science Foundation of China(Nos.52377133 and 52077014)the Youth Talent Support Program of Chongqing(CQYC2021058945)the General Program of the Natural Science Foundation of Chongqing Municipality(CSTB2022NSCQ-MSX0444).
文摘To address the inherent trade-off between mechanical strength and repair efficiency in conventional microcapsule-based self-healing technologies,this study presents an eggshell-inspired approach for fabricating high-load rigid porous microcapsules(HLRPMs)through subcritical water etching.By optimizing the subcritical water treatment parameters(OH−concentration:0.031 mol/L,tem-perature:240°C,duration:1.5 h),nanoscale through-holes were generated on hollow glass microspheres(shell thickness≈700 nm).The subsequent gradient pressure infiltration of flaxseed oil enabled a record-high core content of 88.2%.Systematic investigations demonstrated that incorporating 3 wt%HLRPMs into epoxy resin composites preserved excellent dielectric properties(breakdown strength≥30 kV/mm)and enhanced tensile strength by 7.52%.In addressing multimodal damage,the system achieved a 95.5%filling efficiency for mechanical scratches,a 97.0%reduction in frictional damage depth,and a 96.2%recovery of insulation following electrical treeing.This biomimetic microcapsule system concurrently improved self-healing capability and matrix performance,offering a promising strategy for the development of next-generation smart insulating materials.
基金Funded by the International Science and Technology Cooperation Project of the Key R&D Program of Science and Technology Innovation Yongjiang 2035。
文摘An evaluation method for self-healing capacity was designed,which includes the control of initial cracks and subsequent permeability testing.This method was employed to evaluate the self-healing behavior of mortars incorporating crystalline admixtures(CAs)under various conditions,including water immersion,limewater soaking,and wet-dry cycles,with varying CA dosages and crack widths.The experimental results indicate that cement possesses inherently self-healing capability.Limewater environments inhibits healing compared with water immersion;however,wet-dry cycles enhance the effectiveness of higher CA dosages.Increasing the CA content can not improve healing performance,and wide cracks(0.3 mm)substantially reduce the intrinsic self-healing potential of cement.
