The sensing coverage of a wireless sensor network is an important measure of the quality of service. It is desirable to develop energy efficient methods for relocating mobile sensors in order to achieve optimum sensin...The sensing coverage of a wireless sensor network is an important measure of the quality of service. It is desirable to develop energy efficient methods for relocating mobile sensors in order to achieve optimum sensing coverage. This paper introduces an average distance based self-relocation and self-healing algorithm for randomly deployed mobile sensor networks. No geo-location or relative location information is needed by this algorithm thereby no hardware such as GPS is required. The tradeoff is that sensors need to move longer distance in order to achieve certain coverage. Simulations are conducted in order to evaluate the proposed relocation and self-healing algorithms. An average of 94% coverage is achieved in the cases that we are examined with or without obstacles.展开更多
Resilient Packet Ring (RPR) is a Media Access Control (MAC) layer protocol that operates over a double counter-rotating ring network topology. RPR is designed to enhance Synchronous Digital Hierarchy(SDH) in order to ...Resilient Packet Ring (RPR) is a Media Access Control (MAC) layer protocol that operates over a double counter-rotating ring network topology. RPR is designed to enhance Synchronous Digital Hierarchy(SDH) in order to handle data traffic more efficiently. Since Intelligent Protection Switching(IPS) is one of the key technologies in ring networks, RPR provides two intelligent protection algorithms: steering and wrapping. While wrapping in RPR in essence inherits the automatic protection switching(APS) algorithm of SDH, it also wastes the bandwidth on the wrapping ringlets and may result in severe congestion. Whereas steering in RPR provides high bandwidth utilization, its switching speed is low, because it is indeed a high layer's restoration algorithm. In this paper, integrated self-healing(ISH) algorithm as an effective algorithm for RPR is proposed, which synthesizes the merits of the two algorithms by transporting healing signal and computing routing in MAC layer. At last, the performance of ISH algorithm is analyzed and simulated.展开更多
Azobenzene-based polymer actuators show great promise for photoactuation owing to their unique photoisomerization behavior and tailorable molecular programmability.However,conventional systems are limited by inadequat...Azobenzene-based polymer actuators show great promise for photoactuation owing to their unique photoisomerization behavior and tailorable molecular programmability.However,conventional systems are limited by inadequate mechanical robustness,self-healing,and recyclability,hindering their practical implementation.Herein,we present a high-performance azobenzene-functionalized polyurethane(AzoPU)elastomer actuator designed via molecular engineering of photoactive azobenzene moieties and dynamic disulfide bonds.AzoPU exhibits exceptional mechanical properties with retained performance after multiple reshaping cycles,enabled by well-engineered hard-soft segments and synergistic stress dissipation from weak covalent bonds/hierarchical hydrogen bonds.It achieves over 93%self-healing efficiency at room temperature owing to the synergistic interplay of disulfide bonds in the polymer backbone and intermolecular hydrogen bonds.Furthermore,it demonstrates remarkable light-triggered actuation behavior,achieving a phototropic bending angle exceeding 180°toward the light source within 45 s.To showcase its practical potential,proof-of-concept photoactuated devices with flower-,hook-,and gripper-like and local-orientation processed strip-shaped structures were fabricated,which exhibited rapid and reversible light-triggered deformation.This study proposes a novel strategy for the development of intelligent polymeric materials that integrate light responsiveness,self-healing,and recyclability,thus holding great promise for applications in flexible electronics,smart actuators,and sustainable functional materials.展开更多
Thermochromic soft materials are flexible functional materials that adaptively tune optical properties(transmittance,reflectance,or scattering)with temperature for thermal modulation.Herein,a laminated thermochromic g...Thermochromic soft materials are flexible functional materials that adaptively tune optical properties(transmittance,reflectance,or scattering)with temperature for thermal modulation.Herein,a laminated thermochromic gel(DEE-DA)is synthesized by encapsulating a thermochromic hydrogel(DA)between two hydrophobic ionogels(DEE)in a stacked configuration.The synergy of multiple dynamic bonds endows the DEE-DA gel with exceptional mechanical properties and remarkable self-healing capability(98.8%at 30℃).More importantly,attributed to the temperature-responsive reversible cleavage and recombination of hydrogen bonds and borate ester bonds,DEE-DA gel demonstrates tunable transmittance with a light modulation efficiency of 85.45%.In response to the various external conditions,the gel can auto-adjust the optical properties to avoid sun irradiation or heat loss.Accordingly,the gel enables efficient dual-mode thermal modulation across a broad temperature range to realize thermal management.The research proposes gel thermochromism and laminated durability enhancement for adaptive materials in smart buildings and wearables.展开更多
Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels...Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels with excellent environmental stability,efficient room-temperature self-healing and recyclability properties,as well as amphiphobic slippery surfaces,are fabricated by incorporating binary ionic liquids into a rationally designed self-healing polyurethane with perfluoroalkyl side chains.The outstanding and stable thermochromic performance of the resulting ionogels stems from the hydrogen bond-mediated,confined,and reversible phase separation of ionic liquids within the polyurethane network,enabling the ionogels to effectively reduce indoor temperatures and enhance the comfort of occupants.The surface-enriched perfluoroalkyl side chains enable various liquids,including water,alkanes,and edible oils,to easily slide off the ionogel surface without leaving any residue,preventing the transmittance decrease and thermochromic performance degradation caused by contaminations.The dynamic hydrogen bonds within the polyurethane network enable the ionogels to repeatedly heal physical and chemical damages,as well as to be recycled multiple times without performance loss,thereby reducing maintenance costs and minimizing material waste.This study provides a novel approach to developing advanced thermochromic materials for smart windows,potentially improving the building energy efficiency and sustainability.展开更多
Although poly(urethane-urea)elastomers(PUEs)possess excellent mechanical properties and durability,their inherent flammability and inability to self-repair after damage significantly limits their applications in high-...Although poly(urethane-urea)elastomers(PUEs)possess excellent mechanical properties and durability,their inherent flammability and inability to self-repair after damage significantly limits their applications in high-end fields.To address this challenge,this study employs a supramolecular chemistry approach by simultaneously incorporating multiple hydrogen bonds as dynamic cross-linking points and a phosphorus-nitrogen synergistic flame-retardant structure into the poly(urethane-urea)network.The multiple hydrogen bonds endow the material with efficient intrinsic self-healing capability,while the phosphorus-nitrogen flame retardant ensures outstanding thermal stability and flame resistance,leading to the successful synthesis of a high-performance multifunctional poly(urethane-urea)elastomer.Experimental results demonstrated that when the content of the flame retardant diethyl(2-((2-aminoethyl)amino)ethyl)phosphoramidate(DEPTA)was 10 wt%,the resulting PUE/10%DEPTA achieved a V-0 rating in the vertical burning test,with a limiting oxygen index(LOI)of 30%.Concurrently,the elastomer maintained good toughness,exhibiting a tensile strength of 27.3 MPa,an elongation at break of 601%,and a self-healing efficiency of up to 94.46%.This breakthrough shows significant promise for advanced engineering applications that demand fire safety,structural durability,and extended service life through self-repair.展开更多
This study presents a physics-informed modelling framework that combines finite element method(FEM)simulations and supervised machine learning(ML)to predict the self-healing performance of microbial concrete.A FEniCS-...This study presents a physics-informed modelling framework that combines finite element method(FEM)simulations and supervised machine learning(ML)to predict the self-healing performance of microbial concrete.A FEniCS-based FEM platform resolves multiphysics phenomena including nutrient diffusion,microbial CaCO_(3) precipitation,and stiffness recovery.These simulations,together with experimental data,are used to train ML models(Random Forest yielding normalized RMSE≈0.10)capable of predicting performance over a wide range of design parameters.Feature importance analysis identifies curing temperature,calcium carbonate precipitation rate,crack width,bacterial strain,and encapsulation method as the most influential parameters.The coupled FEM-ML approach enables sensitivity analysis,design optimization,and prediction beyond the training dataset(consistently exceeding 90%healing efficiency).Experimental validation confirms model robustness in both crack closure and strength recovery.This FEM–ML pipeline thus offers a generalizable,interpretable,and scalable strategy for the design of intelligent,self-adaptive construction materials.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
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
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
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
Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to add...Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to address these issues.However,the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges,further complicated by the substantial volume expansion of Si.In this work,we chemically grafted a flame-retardant,self-healing polyurethane-thiourea polymer onto Li_(7)P_(3)S_(11)(SHPUSB-40%LPS)via nucleophilic addition,creating an electrolyte with exceptional ionic conductivity,high elasticity,and strong compatibility with Si anodes.We observed that FSI^(-)was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies,enhancing Li^(+)transport.Furthermore,SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds,enabling self-assembly of the electrolyte at the interface.This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles.As a result,the Si anode with SHPUSB-40%LPS presents excellent cycling stability,retaining nearly 53.5%of its capacity after 300 cycles.The practical applicability of this design was validated in a 2 Ah all-solid-state Si‖LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)pouch cell,which maintained a stable Li-ion storage capacity retention of 76.3%after 350cycles at 0.5C.This novel solid-state electrolyte with selfhealing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.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
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
The rapid proliferation of renewable energy integration and escalating grid operational complexity have intensified demands for resilient self-healing mechanisms in modern power systems.Conventional approaches relying...The rapid proliferation of renewable energy integration and escalating grid operational complexity have intensified demands for resilient self-healing mechanisms in modern power systems.Conventional approaches relying on static models and heuristic rules exhibit limitations in addressing dynamic fault propagation and multimodal data fusion.This study proposes a Transformer-enhanced intelligent microgrid self-healing framework that synergizes large languagemodels(LLMs)with adaptive optimization,achieving three key innovations:(1)Ahierarchical attention mechanism incorporating grid impedance characteristics for spatiotemporal feature extraction,(2)Dynamic covariance estimation Kalman filtering with wavelet packet energy entropy thresholds(Daubechies-4 basis,6-level decomposition),and(3)A grouping-stratified ant colony optimization algorithm featuring penalty-based pheromone updating.Validated on IEEE 33/100-node systems,our framework demonstrates 96.7%fault localization accuracy(23%improvement over STGCN)and 0.82-s protection delay,outperforming MILP-basedmethods by 37%in reconfiguration speed.The system maintains 98.4%self-healing success rate under cascading faults,resolving 89.3%of phase-toground faults within 500 ms through adaptive impedance matching.Field tests on 220 kV substations with 45%renewable penetration show 99.1%voltage stability(±5%deviation threshold)and 40%communication efficiency gains via compressed GOOSE message parsing.Comparative analysis reveals 12.6×faster convergence than conventional ACO in 1000-node networks,with 95.2%robustness against±25%load fluctuations.These advancements provide a scalable solution for real-time fault recovery in renewable-dense grids,reducing outage duration by 63%inmulti-agent simulations compared to centralized architectures.展开更多
In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulati...In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulations are made to these queue models, and detailed analyses are presented to the effect of both the three implementation schemes of self-healing function and some architecture parameters in VP switches on self-healing performance.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
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
Smart materials with self-healing properties are highly desired.This study investigates graphene-incorporated styrene-isoprene-styrene(SIS)nanocomposites for their self-healing property assisted by Infrared(IR)and mic...Smart materials with self-healing properties are highly desired.This study investigates graphene-incorporated styrene-isoprene-styrene(SIS)nanocomposites for their self-healing property assisted by Infrared(IR)and microwave radiation.The good thermal conductivity and energy-absorbing capacity of graphene offer self-healing capability to SIS/GnP nanocomposites due to their exposure to IR and microwave radiation.The absorbed energy in graphene is transferred to the SIS matrix,facilitating the diffusion,re-entanglement,and restoration of the SIS polymer chains,resulting in multiple times self-healing capabilities using various external stimuli.All SIS/GnP nanocomposite samples exhibit self-healing behavior,and the healing efficiency rises with increasing GnP content in the nanocomposites and healing time.The cut mark on the SIS/GnP nanocomposite sample(having 10 wt.%of GnP)entirely disappears when the sample is placed in contact with IR radiation(at 250 W)for 10 min.In addition,the sample is completely healed when exposed to microwave radiation(at 900 W)for less than 30 s.The good dispersion of the graphene nanoplates in the SIS matrix was observed in SEM micrographs.Strong interfacial interactions between the SIS copolymer chains and exfoliated graphene(GnP)due toπ-πstacking stabilize graphene dispersion against agglomeration.The effect of graphene nanoplates on the SIS thermoplastic elastomer’s thermal stability and phase transition is also studied by Thermo-gravimetric analysis(TGA)and Differential Scanning Calorimetry(DSC)analysis.展开更多
文摘The sensing coverage of a wireless sensor network is an important measure of the quality of service. It is desirable to develop energy efficient methods for relocating mobile sensors in order to achieve optimum sensing coverage. This paper introduces an average distance based self-relocation and self-healing algorithm for randomly deployed mobile sensor networks. No geo-location or relative location information is needed by this algorithm thereby no hardware such as GPS is required. The tradeoff is that sensors need to move longer distance in order to achieve certain coverage. Simulations are conducted in order to evaluate the proposed relocation and self-healing algorithms. An average of 94% coverage is achieved in the cases that we are examined with or without obstacles.
文摘Resilient Packet Ring (RPR) is a Media Access Control (MAC) layer protocol that operates over a double counter-rotating ring network topology. RPR is designed to enhance Synchronous Digital Hierarchy(SDH) in order to handle data traffic more efficiently. Since Intelligent Protection Switching(IPS) is one of the key technologies in ring networks, RPR provides two intelligent protection algorithms: steering and wrapping. While wrapping in RPR in essence inherits the automatic protection switching(APS) algorithm of SDH, it also wastes the bandwidth on the wrapping ringlets and may result in severe congestion. Whereas steering in RPR provides high bandwidth utilization, its switching speed is low, because it is indeed a high layer's restoration algorithm. In this paper, integrated self-healing(ISH) algorithm as an effective algorithm for RPR is proposed, which synthesizes the merits of the two algorithms by transporting healing signal and computing routing in MAC layer. At last, the performance of ISH algorithm is analyzed and simulated.
基金financially supported by the National Natural Science Foundation of China(No.52503154)Shandong Provincial Natural Science Foundation(Nos.ZR2022MB034 and ZR2025QC512)。
文摘Azobenzene-based polymer actuators show great promise for photoactuation owing to their unique photoisomerization behavior and tailorable molecular programmability.However,conventional systems are limited by inadequate mechanical robustness,self-healing,and recyclability,hindering their practical implementation.Herein,we present a high-performance azobenzene-functionalized polyurethane(AzoPU)elastomer actuator designed via molecular engineering of photoactive azobenzene moieties and dynamic disulfide bonds.AzoPU exhibits exceptional mechanical properties with retained performance after multiple reshaping cycles,enabled by well-engineered hard-soft segments and synergistic stress dissipation from weak covalent bonds/hierarchical hydrogen bonds.It achieves over 93%self-healing efficiency at room temperature owing to the synergistic interplay of disulfide bonds in the polymer backbone and intermolecular hydrogen bonds.Furthermore,it demonstrates remarkable light-triggered actuation behavior,achieving a phototropic bending angle exceeding 180°toward the light source within 45 s.To showcase its practical potential,proof-of-concept photoactuated devices with flower-,hook-,and gripper-like and local-orientation processed strip-shaped structures were fabricated,which exhibited rapid and reversible light-triggered deformation.This study proposes a novel strategy for the development of intelligent polymeric materials that integrate light responsiveness,self-healing,and recyclability,thus holding great promise for applications in flexible electronics,smart actuators,and sustainable functional materials.
基金supported by the Yunlong Lake Laboratory of Deep Underground Science and Engineering Project(104024004)the National Natural Science Foundation of China(62288102)+2 种基金the Key Project of Basic Research Program of Jiangsu Province(BK20243036)the State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and astronautics)(MCAS-E-0124K01)the Cultivation Program for the Excellent Doctoral Dissertation of Nanjing Tech University(2023-06)。
文摘Thermochromic soft materials are flexible functional materials that adaptively tune optical properties(transmittance,reflectance,or scattering)with temperature for thermal modulation.Herein,a laminated thermochromic gel(DEE-DA)is synthesized by encapsulating a thermochromic hydrogel(DA)between two hydrophobic ionogels(DEE)in a stacked configuration.The synergy of multiple dynamic bonds endows the DEE-DA gel with exceptional mechanical properties and remarkable self-healing capability(98.8%at 30℃).More importantly,attributed to the temperature-responsive reversible cleavage and recombination of hydrogen bonds and borate ester bonds,DEE-DA gel demonstrates tunable transmittance with a light modulation efficiency of 85.45%.In response to the various external conditions,the gel can auto-adjust the optical properties to avoid sun irradiation or heat loss.Accordingly,the gel enables efficient dual-mode thermal modulation across a broad temperature range to realize thermal management.The research proposes gel thermochromism and laminated durability enhancement for adaptive materials in smart buildings and wearables.
基金supported by the National Natural Science Foundation of China(22475082,21971083)。
文摘Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels with excellent environmental stability,efficient room-temperature self-healing and recyclability properties,as well as amphiphobic slippery surfaces,are fabricated by incorporating binary ionic liquids into a rationally designed self-healing polyurethane with perfluoroalkyl side chains.The outstanding and stable thermochromic performance of the resulting ionogels stems from the hydrogen bond-mediated,confined,and reversible phase separation of ionic liquids within the polyurethane network,enabling the ionogels to effectively reduce indoor temperatures and enhance the comfort of occupants.The surface-enriched perfluoroalkyl side chains enable various liquids,including water,alkanes,and edible oils,to easily slide off the ionogel surface without leaving any residue,preventing the transmittance decrease and thermochromic performance degradation caused by contaminations.The dynamic hydrogen bonds within the polyurethane network enable the ionogels to repeatedly heal physical and chemical damages,as well as to be recycled multiple times without performance loss,thereby reducing maintenance costs and minimizing material waste.This study provides a novel approach to developing advanced thermochromic materials for smart windows,potentially improving the building energy efficiency and sustainability.
文摘Although poly(urethane-urea)elastomers(PUEs)possess excellent mechanical properties and durability,their inherent flammability and inability to self-repair after damage significantly limits their applications in high-end fields.To address this challenge,this study employs a supramolecular chemistry approach by simultaneously incorporating multiple hydrogen bonds as dynamic cross-linking points and a phosphorus-nitrogen synergistic flame-retardant structure into the poly(urethane-urea)network.The multiple hydrogen bonds endow the material with efficient intrinsic self-healing capability,while the phosphorus-nitrogen flame retardant ensures outstanding thermal stability and flame resistance,leading to the successful synthesis of a high-performance multifunctional poly(urethane-urea)elastomer.Experimental results demonstrated that when the content of the flame retardant diethyl(2-((2-aminoethyl)amino)ethyl)phosphoramidate(DEPTA)was 10 wt%,the resulting PUE/10%DEPTA achieved a V-0 rating in the vertical burning test,with a limiting oxygen index(LOI)of 30%.Concurrently,the elastomer maintained good toughness,exhibiting a tensile strength of 27.3 MPa,an elongation at break of 601%,and a self-healing efficiency of up to 94.46%.This breakthrough shows significant promise for advanced engineering applications that demand fire safety,structural durability,and extended service life through self-repair.
基金funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie Grant Agreement No.945478(SASPRO2)supported by the ReBuilt project:Circular and Digital Renewal of Central Europe Construction and Building Sector CE0100390 ReBuiltthe Slovak Research and Development Agency under APVV-23-0383 and the Slovak Grant Agency VEGA No.2/0080/24.
文摘This study presents a physics-informed modelling framework that combines finite element method(FEM)simulations and supervised machine learning(ML)to predict the self-healing performance of microbial concrete.A FEniCS-based FEM platform resolves multiphysics phenomena including nutrient diffusion,microbial CaCO_(3) precipitation,and stiffness recovery.These simulations,together with experimental data,are used to train ML models(Random Forest yielding normalized RMSE≈0.10)capable of predicting performance over a wide range of design parameters.Feature importance analysis identifies curing temperature,calcium carbonate precipitation rate,crack width,bacterial strain,and encapsulation method as the most influential parameters.The coupled FEM-ML approach enables sensitivity analysis,design optimization,and prediction beyond the training dataset(consistently exceeding 90%healing efficiency).Experimental validation confirms model robustness in both crack closure and strength recovery.This FEM–ML pipeline thus offers a generalizable,interpretable,and scalable strategy for the design of intelligent,self-adaptive construction materials.
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.
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.
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 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 financially by the National Natural Science Foundation of China(No.52172202)Science and Technology Program of Guangzhou,China(No.SL2024A03J00326)+1 种基金Key Research and Development project of High-Level Scientific and Technological Talent Introduction for Luliang City(No.2023RC27)the Basic Research Program(Free Exploration Category)Project for Shanxi Province(No.202303021222251)
文摘Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to address these issues.However,the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges,further complicated by the substantial volume expansion of Si.In this work,we chemically grafted a flame-retardant,self-healing polyurethane-thiourea polymer onto Li_(7)P_(3)S_(11)(SHPUSB-40%LPS)via nucleophilic addition,creating an electrolyte with exceptional ionic conductivity,high elasticity,and strong compatibility with Si anodes.We observed that FSI^(-)was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies,enhancing Li^(+)transport.Furthermore,SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds,enabling self-assembly of the electrolyte at the interface.This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles.As a result,the Si anode with SHPUSB-40%LPS presents excellent cycling stability,retaining nearly 53.5%of its capacity after 300 cycles.The practical applicability of this design was validated in a 2 Ah all-solid-state Si‖LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)pouch cell,which maintained a stable Li-ion storage capacity retention of 76.3%after 350cycles at 0.5C.This novel solid-state electrolyte with selfhealing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.
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.
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.
基金the project“Research on Power SafetyDecision Support SystemBased on Large Language Models”(Science and Technology Project of Huaian Hongneng Group Co.,Ltd.)under Contract No.SGTYHT/23-JS-001.
文摘The rapid proliferation of renewable energy integration and escalating grid operational complexity have intensified demands for resilient self-healing mechanisms in modern power systems.Conventional approaches relying on static models and heuristic rules exhibit limitations in addressing dynamic fault propagation and multimodal data fusion.This study proposes a Transformer-enhanced intelligent microgrid self-healing framework that synergizes large languagemodels(LLMs)with adaptive optimization,achieving three key innovations:(1)Ahierarchical attention mechanism incorporating grid impedance characteristics for spatiotemporal feature extraction,(2)Dynamic covariance estimation Kalman filtering with wavelet packet energy entropy thresholds(Daubechies-4 basis,6-level decomposition),and(3)A grouping-stratified ant colony optimization algorithm featuring penalty-based pheromone updating.Validated on IEEE 33/100-node systems,our framework demonstrates 96.7%fault localization accuracy(23%improvement over STGCN)and 0.82-s protection delay,outperforming MILP-basedmethods by 37%in reconfiguration speed.The system maintains 98.4%self-healing success rate under cascading faults,resolving 89.3%of phase-toground faults within 500 ms through adaptive impedance matching.Field tests on 220 kV substations with 45%renewable penetration show 99.1%voltage stability(±5%deviation threshold)and 40%communication efficiency gains via compressed GOOSE message parsing.Comparative analysis reveals 12.6×faster convergence than conventional ACO in 1000-node networks,with 95.2%robustness against±25%load fluctuations.These advancements provide a scalable solution for real-time fault recovery in renewable-dense grids,reducing outage duration by 63%inmulti-agent simulations compared to centralized architectures.
基金Supported by the National Natural Science Foundation of China
文摘In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulations are made to these queue models, and detailed analyses are presented to the effect of both the three implementation schemes of self-healing function and some architecture parameters in VP switches on self-healing performance.
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.
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.
文摘Smart materials with self-healing properties are highly desired.This study investigates graphene-incorporated styrene-isoprene-styrene(SIS)nanocomposites for their self-healing property assisted by Infrared(IR)and microwave radiation.The good thermal conductivity and energy-absorbing capacity of graphene offer self-healing capability to SIS/GnP nanocomposites due to their exposure to IR and microwave radiation.The absorbed energy in graphene is transferred to the SIS matrix,facilitating the diffusion,re-entanglement,and restoration of the SIS polymer chains,resulting in multiple times self-healing capabilities using various external stimuli.All SIS/GnP nanocomposite samples exhibit self-healing behavior,and the healing efficiency rises with increasing GnP content in the nanocomposites and healing time.The cut mark on the SIS/GnP nanocomposite sample(having 10 wt.%of GnP)entirely disappears when the sample is placed in contact with IR radiation(at 250 W)for 10 min.In addition,the sample is completely healed when exposed to microwave radiation(at 900 W)for less than 30 s.The good dispersion of the graphene nanoplates in the SIS matrix was observed in SEM micrographs.Strong interfacial interactions between the SIS copolymer chains and exfoliated graphene(GnP)due toπ-πstacking stabilize graphene dispersion against agglomeration.The effect of graphene nanoplates on the SIS thermoplastic elastomer’s thermal stability and phase transition is also studied by Thermo-gravimetric analysis(TGA)and Differential Scanning Calorimetry(DSC)analysis.
