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
Electrocardiogram(ECG)sensor is emerging as an essential medical device for diagnosing various cardiovascular diseases in modern people.Conventional ECG sensors have investigated by several researchers,but they still ...Electrocardiogram(ECG)sensor is emerging as an essential medical device for diagnosing various cardiovascular diseases in modern people.Conventional ECG sensors have investigated by several researchers,but they still have significant issues of discomfort in wearing,easy swelling,poor electrical conductivity,and signal inaccuracy.Here,we demonstrate a hydrogel nanocomposite-based ECG sensor patches,monolithically integrated with a hydrogel-based biocompatible electrode and an electromagnetic interference(EMI)shielding layer in a single unit.The developed device with low impedance(20 kΩ)exhibited excellent mechanical properties including adhesion force(35.8 N m^(–1)),multiple detachability(5 times),stretching/twisting stability and self-healing characteristic.The ECG sensor displayed superior long-term humidity stability for 30 days,showing superior biocompatibility.Finally,the ECG patch with high EMI shielding property monitored human vital signal and pulse rate changes in real-time.展开更多
The infection induced by implantation of biomedical materials may result from the biofilm formation after bacteria attachment.Hence,the antibiofilm surface coating represents a novel technique to improve the antibacte...The infection induced by implantation of biomedical materials may result from the biofilm formation after bacteria attachment.Hence,the antibiofilm surface coating represents a novel technique to improve the antibacterial activity of biomedical materials.The traditional antibiofilm surface coatings exhibited some disadvantages and provided a limited service life.In this work,we used polyethyleneimine grafted 3-maleimidopropionic acid(PEIM)and poly(acrylic acid)grafted 2-furfurylamine(PAAF)to achieve robust and self-healable crosslinked multilayer coatings,employing Layer-by-Layer(LbL)self-assembly technique and Diels-Alder reaction.Then,thiol-terminated poly((3-acrylamidopropyl)trimethylammonium chloride)(PAMPTMA-SH)was grafted onto the crosslinked multilayer coating by thiol-ene click reaction to form a novel multilayer coating(PEIM/PAAF)_(10)-PAMPTMA.We found that this coating showed robust and self-healable activity,and significantly inhibited the bacterial growth and biofilm formation after infection with Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)by in vitro and in vivo assays for 120 h.In addition,the multilayer coating did not induce significant hemolysis or affect the cell viability of red blood cells.In vivo studies also showed that(PEIM/PAAF)_(10)-PAMPTMA coating efficiently blocked the infiltration of inflammatory cells and gene expression in the mouse skin challenged with E coli or S.aureus.Taken together,these results showed that the prepared multilayer coating exhibited strong antibiofilm activity and provided a new strategy for the application of highly efficient antibiofilm surface coating of biomedical materials.展开更多
Integrating smart functions into one flexible electronic is vastly valuable in improving their working performances and broadening applications.Here,this work reports a ultraflexible,highly efficient electromagnetic i...Integrating smart functions into one flexible electronic is vastly valuable in improving their working performances and broadening applications.Here,this work reports a ultraflexible,highly efficient electromagnetic interference(EMI)shielding,and self-healable triboelectric nanogenerator(TENG)that is assembled by modified Ti_(3)C_(2)T_(x) MXene(m-MXene)-based nanocomposite elastomers.Benefitting from the excellent electronegativity of m-MXene,the single-electrode mode-based TENG can generate high open-circuit voltage(V_(oc))oscillating between-65 and 245 V,high short-circuit current(I_(sc))of 29 μA,and an instantaneously maximum peak power density of 1150 mW m^(-2) that can power twenty light-emitting diodes(LEDs).Moreover,the resultant TENG possesses outstanding EMI shielding performance with the maximum shielding effectiveness of 48.1 dB in the X-band.The enhanced shielding capability is dominated by the electromagnetic absorption owning to high conduction loss in m-MXene network,multiple reflections between m-MXene sheets,and polarization effect on the surface of m-MXene sheets.Additionally,a self-powered wearable sensor is fabricated based on the as-prepared TENG.The sensor shows an intrinsic healing ability with healing efficiency of 98.2% and can accurately detect the human large-scale motions and delicate physical signal.This work provides an enhanced way to fabricate the wearable electronics integrated with smart functions,and the reported MXene-based TENG may have a broad prospect in the fields of aerospace,artificial intelligence,and healthcare systems.展开更多
Polyurethane is widely used for its versatility in design and range of performance.Self-healing and recyclable dynamic polyurethane networks have attracted extensive attention due to their potential to extend service ...Polyurethane is widely used for its versatility in design and range of performance.Self-healing and recyclable dynamic polyurethane networks have attracted extensive attention due to their potential to extend service life and ensure safety in use,as well as to promote sustainable use of resources.Developing green and environment-friendly methods to obtain this material is an interesting and challenging task,as the majority of current dynamic polyurethane networks utilize the solution polymerization method.The use of solvents makes the processes complicated,harmful to environment,and increase the cost.Poly(oxime-urethanes)(POUs)are emerging dynamic polyurethanes and show great potential in diverse fields,such as biomaterials,hot melt adhesives,and flexible electronics.In this study,we utilized the solubility properties of dimethylglyoxime in raw material poly(ethylene glycol)to prepare POUs through bulk polymerization for the first time.This method is simple,convenient and cost-efficient.Simultaneously,copper ion coordination improves POUs strength and dynamic properties,with mechanical strength up from 0.54 MPa to 1.03 MPa and self-healing recovery rate up from 85.5%to 91.8%,and activation energy down from 119.6 k J/mol to 95.4 k J/mol.To demonstrate the application of this technology,self-healing and stretchable circuits are constructed from this dynamic polyurethane network.展开更多
Unexpected ice accumulation tends to cause many problems or even disasters in our daily life.Based on the superior electrothermal and photothermal function of the carbon nanotubes,we introduced a superhydrophobic/elec...Unexpected ice accumulation tends to cause many problems or even disasters in our daily life.Based on the superior electrothermal and photothermal function of the carbon nanotubes,we introduced a superhydrophobic/electrothermal/photothermal synergistically anti-icing strategy.When a voltage of 15 V was applied to the superhydrophobic sample,the surface could rapidly melt the ice layer(~3 mm thickness)within 530 s at the environmental temperature of-25℃.When the near-infrared light(808 nm)irradiates on the superhydrophobic sample,the ice could be rapidly removed after 460 s.It was found that the superhydrophobicity helps the melted water to roll off immediately,and then solves the re-freeze problem the traditional surfaces facing.Moreover,the ice can be completely melted with 120 s when the superhydrophobic/electrothermal/photothermal synergistically anti-icing strategy was utilized.To improve the mechanical robustness for practical application,both nanoscale carbon nanotubes and microscale carbon powders were utilized to construct hierarchical structure.Then these dual-scale fillers were sprinkled onto the semi-cured elastomer substrate to prepare partially embedded structure.Both hierarchical structure and partially embedded structure were obtained after completely curing the substrate,which imparts excellent abrasion resistance(12.50 kPa,16.00 m)to the prepared sample.Moreover,self-healable poly(urea–urethane)elastomer was introduced as the substrate.Thus,the cutted superhydrophobic sample can be mended by simply contacting at room temperature.展开更多
Flexible conductive fibers are essential for wearable electronics and smart electronic textiles.However,in complex operating conditions,conductive fibers will inevitably fracture or damage.Herein,we have developed an ...Flexible conductive fibers are essential for wearable electronics and smart electronic textiles.However,in complex operating conditions,conductive fibers will inevitably fracture or damage.Herein,we have developed an elastic conductive self-healable fiber(C-SHF),of which the electrical and mechanical properties can efficiently heal in a wide operating range,including room temperature,underwater,and low temperature.This advantage can be owed to the combination of reversible covalent imine bond and disulfide bond,as well as the instantaneous self-healing ability of liquid metal.The C-SHF,with stretchability,conductivity stability,and universal self-healing properties,can be used as an electrical signal transmission line at high strain and under different operating conditions.Besides,C-SHF was assembled into a double-layer capacitor structure to construct a self-healable sensor,which can effectively respond to pressure as a wearable motion detector.展开更多
The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible supercapacitor.For this purpose,the electroconductive polym...The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible supercapacitor.For this purpose,the electroconductive polymer brushes(EPB)was elaborated.The synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the EPBs.Electroconducting films were prepared by casting of EPB solution with subsequent drying.Investigation of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA samples.It was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.展开更多
Crosslinking natural rubber (NR) and styrene butadiene rubber (SBR) composites with carbon black (CB) have been utilized in the tire tread industry.A sulfur-based lightly crosslinker can potentially enhance the self-h...Crosslinking natural rubber (NR) and styrene butadiene rubber (SBR) composites with carbon black (CB) have been utilized in the tire tread industry.A sulfur-based lightly crosslinker can potentially enhance the self-healing capabilities of rubber.Moreover,the rubber composites were studied for non-covalent interactions between the benzene rings of SBR and CB.In this research,rubber samples were prepared,and their structure was investigated using Fourier transform infrared (FTIR),and Raman spectroscopy.The red shift in Raman spectroscopy confirmed noncovalent interaction or hydrophobic interaction between SBR and CB in NR/SBR composites exposed to CB due to environmental change.The differential scanning calorimetry (DSC) thermograms showed that NR and SBR were incompatible.Additionally,the mechanical properties of these rubber blends were enhanced as the proportion of NR increased.The maximum self-healing performance reached 40%for the formulation containing 25 phr NR and 75 phr SBR,which also saved energy with low chain end movements.Therefore,these composites could be utilized as a semi-empirical model for studying crosslinked rubber blends,specifically in the rubber tire industry.展开更多
Self-healable polyacrylamide-based hydrogels were prepared at room temperature via a one-step emulsion copolymerization of acrylamide（AM）,dodecyl 2-methacryIate（DM）,and 5-acetylaminopentyl acrylate（AAPA） using s...Self-healable polyacrylamide-based hydrogels were prepared at room temperature via a one-step emulsion copolymerization of acrylamide（AM）,dodecyl 2-methacryIate（DM）,and 5-acetylaminopentyl acrylate（AAPA） using sodium dodecyl sulfonate（SDS） as the emulsifier and ammonium persulfate（APS）as the initiator.The produced linear multi-block copolymer chains are composed of randomly-linked hydrophilic polyacrylamide segments（PAM） and hydrophobic segments constituted by DM and AAPA units（P（DM-co-AAPA））.The P（DM-co-AAPA） segments will self-aggregate into hydrophobic microdomains during the polymerization process driven by the hydrophobic interactions,and finally separate from water phase,acting as the crosslinks and leading to the formation of strong hydrogels with a storage modulus as high as 400 Pa.These hydrophobic microdomains will be dissolved in water when the temperature increases to 70℃,resulting in a temperature-responsive reversible sol-gel transition of the prepared hydrogels.Furthermore,the prepared hydrogels have excellent self-healing ability.The broken hydrogels can be automatically healed into a body with a same strength within 2-min＇s contact.This work provides a new simple way to prepare reversible physical crosslinked hydrogel with high strength and self-healing efficiency.展开更多
Robust and reliable piezo-ionic materials that are both crack resistant and selfhealable like biological skin hold great promise for applications inflexible electronics and intelligent systems with prolonged service l...Robust and reliable piezo-ionic materials that are both crack resistant and selfhealable like biological skin hold great promise for applications inflexible electronics and intelligent systems with prolonged service lives.However,such a combination of high toughness,superior crack resistance,autonomous self-healing and effective control of ion dynamics is rarely seen in artificial iontronic skin because these features are seemingly incompatible in materials design.Here,we resolve this perennial mismatch through a molecularly engineered strategy of implanting carboxyl-functionalized groups into the dynamic hard domain structure of synthesized poly(urethane-urea).This design provides an ultra-high fracture energy of 211.27 kJ m^(-2)that is over 123.54 times that of tough human skin,while maintaining skin-like stretchability,elasticity,and autonomous self-healing with a 96.40%healing efficiency.Moreover,the carboxyl anion group allows the dynamic confinement of ionic fluids though electrostatic interaction,thereby ensuring a remarkable pressure sensitivity of 7.03 kPa^(-1)for the tactile sensors.As such,we successfully demonstrated the enormous potential ability of this skin-like piezoionic sensor for biomedical monitoring and robotic item identification,which indicates promising future uses in flexible electronics and human-machine interactions.展开更多
For room temperature self-healing triboelectric nanogenerators(TENGs);the inherent contradiction between mechanical strength and self-healing properties was an urgent problem to be solved.Based on the phenol-carbamate...For room temperature self-healing triboelectric nanogenerators(TENGs);the inherent contradiction between mechanical strength and self-healing properties was an urgent problem to be solved.Based on the phenol-carbamate bond;this paper proposed a strategy to design a new molecular structure and coordinate the triple dynamic bonds;which provided a feasible strategy to solve this contradiction.With polytetramethylene ether glycol(M_(n)=1;000)as the soft segment in the main chain of polyurethane(PU);meanwhile methylene diphenyl diisocyanate and 4,4'-dihydroxybiphenyl(BP)as the hard segment and chain extension agent;respectively;the combination of tetrad benzene ring endowed the resultant 4BP-PU withπ-πinteraction.The effective reversible dissociation and association with hydrogen bond not only bestowed 4BP-PU with high mechanical strength(16.14 MPa);but also promoted high self-healing efficiency(94.8%)at room temperature.4BP-PU was selected as the elastic substrate between polydimethylsiloxane and copper sheet to prepare a self-healing TENG to collect energy from natural motion.Consequently;the rational molecular structure design provided new ideas for developing self-healing materials and fabricating energy harvest electronics.展开更多
Bacterial wound infections are a growing challenge in healthcare,posing severe risks like systemic infection,organ failure,and sepsis,with projections predicting over 10 million deaths annually by 2050.Antibacterial h...Bacterial wound infections are a growing challenge in healthcare,posing severe risks like systemic infection,organ failure,and sepsis,with projections predicting over 10 million deaths annually by 2050.Antibacterial hydrogels,with adaptable extracellular matrix-like features,are emerging as promising solutions for treating infectious wounds.However,the antibacterial properties of most of these hydrogels are largely attributed to extrinsic agents,and their mechanisms of action remain poorly understood.Herein we introduce for the first time,modified imidazolidinyl urea(IU)as the polymeric backbone for developing tissue-like antibacterial hydrogels.As-designed hydrogels behave tissue-like mechanical features,outstanding antifreeze behavior,and rapid self-healing capabilities.Molecular dynamics(MD)simulation and density functional theory(DFT)calculation were employed to well-understand the extent of H-bonding and metal-ligand coordination to finetune hydrogels’properties.In vitro studies suggest good biocompatibility of hydrogels against mouse fibroblasts&human skin,lung,and red blood cells,with potential wound healing capacity.Additionally,the hydrogels exhibit good 3D printability and remarkable antibacterial activity,attributed to concentration dependent ROS genera-tion,oxidative stress induction,and subsequent disruption of bacterial membrane.On top of that,in vitro biofilm studies confirmed that developed hydrogels are effective in preventing biofilm formation.Therefore,these tissue-mimetic hydrogels present a promising and effective platform for accelerating wound healing while simulta-neously controlling bacterial infections,offering hope for the future of wound care.展开更多
Self-healing polyurethane-elastomers are highly desired in various fields.However,there is often a trade-off between mechanical properties and dynamic self-healing due to the mutually exclusive mechanism.Herein,we dev...Self-healing polyurethane-elastomers are highly desired in various fields.However,there is often a trade-off between mechanical properties and dynamic self-healing due to the mutually exclusive mechanism.Herein,we develop a self-healable and mechanically robust poly(oxime-urethane)elastomer(Zn-DAPU)to circumvent this inherent trade-off by incorporating zincpyridinyl cross-links into the hydrogen bonding and dynamic oxime-urethane supramolecular-covalent hybrid network.Benefiting from the synergistic strengthening of H-bonding and coordinate interactions,Zn-DAPU network performs tunable toughness with metal ion concentration change,which improves 345.2%and reaches 82.2 MJ m^(-3),with robust tensile strength of 22.8 MPa,Young's modulus of 37.1 MPa,and satisfactory elongation of 815.7%.The healing efficiency can be reached at 91.7%with a restored toughness of 75.4 MJ m^(-3)at 80℃for 10 h.Furthermore,zinc-contained networks exhibit photolysis behavior due to the homolytic cleavage of N-O bonds in oxime-urethane moieties,which can be functionalized further with fluorescamine as the specific information encryption coating with quick response codes(QRs)upon polyester fabric.This work provides valuable guidance towards the development of high-performance self-healing polyurethane and wearable functional materials.展开更多
In 2018,we reported that poly(ether thiourea)(PTUEG_(3)),a glassy polymer with a glass transition temperature(T_(g))of 27℃,can self-heal at 12℃,which updated the preconception that a mechanically robust glassy polym...In 2018,we reported that poly(ether thiourea)(PTUEG_(3)),a glassy polymer with a glass transition temperature(T_(g))of 27℃,can self-heal at 12℃,which updated the preconception that a mechanically robust glassy polymer cannot self-heal below its Tg.Herein,we report a new and even better selfhealable glassy polymer,poly(thioether thiourea)(PTU(C_(2)SSC_(2))),by combining thiourea and alkyl disulfide.This polymer possibly takes advantage of its metathesis-active disulfide bonds,and in fact,it selfhealed even at 10℃ despite the fact that its glass transition temperature(T_(g))was 45℃,which is obviously higher than that of PTUEG3.Although its variant PTU(C_(2)SCCSC_(2))without any-S-S-bonds self-healed at 0℃,its Tg was also low at 25℃.When a disulfide ether unit was copolymerized with a ether thiourea unit,the resulting copolymers showed an distinctly lowered self-healing temperature even though their copolymer sequences contained a T_(g)-raising dicyclohexylmethane unit.PTU(C_(2)SSC_(2))is much less hygroscopic than PTUEG_(3) and therefore can be utilized even in high humidity without plasticization.展开更多
Sporosarcina pasteurii was employed as the strain,with an in-situ magnetization construction,to obtain magnetic microorganisms and oriented self-healing mortar specimens based on them.The magnetic field was used to ac...Sporosarcina pasteurii was employed as the strain,with an in-situ magnetization construction,to obtain magnetic microorganisms and oriented self-healing mortar specimens based on them.The magnetic field was used to achieve the directional migration of magnetic microorganisms during the oriented selfhealing of mortar cracks,improving the rate of self-healing of cracks.The experimental results demonstrate that the magnetic microorganisms are composed of Fe_(3)O_(4)nanosheets attached to the surface of Sporosarcina pasteurii,whose mineralization products are comprised of vaterite primarily.Compared with the pure microbial group,the magnetic microbial group exhibits a faster repair rate,shortening the repair time required to achieve an area repair efficiency of over 90%from 28 days to 14 days,thereby doubling the repair rate.Meanwhile,the area repair efficiency of the magnetic microbial group at 7,14,and 28 days are increased by 50.3%,11.2%,and 4.6%,respectively,compared to the pure microbial group,which are due to the magnetic microorganisms'superior directional migration and mineralization ability,exceeding that of the ordinary microorganisms.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
We mixed Bacillus subtilis and brewing yeast to prepare composite microbial self-healing materials,and studied the self-healing effect of composite microorganisms in mortar cracks of different widths and cracking ages...We mixed Bacillus subtilis and brewing yeast to prepare composite microbial self-healing materials,and studied the self-healing effect of composite microorganisms in mortar cracks of different widths and cracking ages.The experimental results show that the performance and self-healing effect of composite micro-organisms are significantly better than those of single microorganisms.For cracks with widths of 0.2-0.4 mm,the repair effect of the composite microorganisms at 28 days is 42.7%and 71.2%higher than that of pure Bacillus and pure yeast,respectively.The repairing rate of the area with the widths of the cracks of 0.2-0.4,0.4-0.6,and 0.6-0.8 mm are 100%,77.3%,and 53.4%,respectively.The area repair rates corresponding to cracking ages of 56,90,and 180 days are 73.3%,55.4%,and 30.8%,respectively.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
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
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supported by the National Research Foundation of Korea(NRF)grants funded by the Ministry of Science,ICT and Future Planning(MSIT)(RS-2023-00278906 and RS-2024-00408989)supported by Development of advanced bio and medical measurement technology funded by Korea Research Institute of Standards and Science(KRISS-2025-GP2025-0007).
文摘Electrocardiogram(ECG)sensor is emerging as an essential medical device for diagnosing various cardiovascular diseases in modern people.Conventional ECG sensors have investigated by several researchers,but they still have significant issues of discomfort in wearing,easy swelling,poor electrical conductivity,and signal inaccuracy.Here,we demonstrate a hydrogel nanocomposite-based ECG sensor patches,monolithically integrated with a hydrogel-based biocompatible electrode and an electromagnetic interference(EMI)shielding layer in a single unit.The developed device with low impedance(20 kΩ)exhibited excellent mechanical properties including adhesion force(35.8 N m^(–1)),multiple detachability(5 times),stretching/twisting stability and self-healing characteristic.The ECG sensor displayed superior long-term humidity stability for 30 days,showing superior biocompatibility.Finally,the ECG patch with high EMI shielding property monitored human vital signal and pulse rate changes in real-time.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20180963)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.19KJD430001).
文摘The infection induced by implantation of biomedical materials may result from the biofilm formation after bacteria attachment.Hence,the antibiofilm surface coating represents a novel technique to improve the antibacterial activity of biomedical materials.The traditional antibiofilm surface coatings exhibited some disadvantages and provided a limited service life.In this work,we used polyethyleneimine grafted 3-maleimidopropionic acid(PEIM)and poly(acrylic acid)grafted 2-furfurylamine(PAAF)to achieve robust and self-healable crosslinked multilayer coatings,employing Layer-by-Layer(LbL)self-assembly technique and Diels-Alder reaction.Then,thiol-terminated poly((3-acrylamidopropyl)trimethylammonium chloride)(PAMPTMA-SH)was grafted onto the crosslinked multilayer coating by thiol-ene click reaction to form a novel multilayer coating(PEIM/PAAF)_(10)-PAMPTMA.We found that this coating showed robust and self-healable activity,and significantly inhibited the bacterial growth and biofilm formation after infection with Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)by in vitro and in vivo assays for 120 h.In addition,the multilayer coating did not induce significant hemolysis or affect the cell viability of red blood cells.In vivo studies also showed that(PEIM/PAAF)_(10)-PAMPTMA coating efficiently blocked the infiltration of inflammatory cells and gene expression in the mouse skin challenged with E coli or S.aureus.Taken together,these results showed that the prepared multilayer coating exhibited strong antibiofilm activity and provided a new strategy for the application of highly efficient antibiofilm surface coating of biomedical materials.
基金financially supported by the National Natural Science Foundation of China(No.21909230)the Postdoctoral Science Foundation of Shaanxi Province(No.2018BSHEDZZ208)+1 种基金the Project funded by China Postdoctoral Science Foundation(No.2017M623235)the Analytical&Testing Center of Northwestern Polytechnical University for SEM and TEM characterizations and the Open Teat Foundation(No.2020T022)。
文摘Integrating smart functions into one flexible electronic is vastly valuable in improving their working performances and broadening applications.Here,this work reports a ultraflexible,highly efficient electromagnetic interference(EMI)shielding,and self-healable triboelectric nanogenerator(TENG)that is assembled by modified Ti_(3)C_(2)T_(x) MXene(m-MXene)-based nanocomposite elastomers.Benefitting from the excellent electronegativity of m-MXene,the single-electrode mode-based TENG can generate high open-circuit voltage(V_(oc))oscillating between-65 and 245 V,high short-circuit current(I_(sc))of 29 μA,and an instantaneously maximum peak power density of 1150 mW m^(-2) that can power twenty light-emitting diodes(LEDs).Moreover,the resultant TENG possesses outstanding EMI shielding performance with the maximum shielding effectiveness of 48.1 dB in the X-band.The enhanced shielding capability is dominated by the electromagnetic absorption owning to high conduction loss in m-MXene network,multiple reflections between m-MXene sheets,and polarization effect on the surface of m-MXene sheets.Additionally,a self-powered wearable sensor is fabricated based on the as-prepared TENG.The sensor shows an intrinsic healing ability with healing efficiency of 98.2% and can accurately detect the human large-scale motions and delicate physical signal.This work provides an enhanced way to fabricate the wearable electronics integrated with smart functions,and the reported MXene-based TENG may have a broad prospect in the fields of aerospace,artificial intelligence,and healthcare systems.
基金the National Key Research and Development Program of China(No.2021YFC2101800)the National Natural Science Foundation of China(Nos.52173117 and 21991123)+3 种基金the Natural Science Foundation of Shanghai(No.20ZR1402500)Belt&Road Young Scientist Exchanges Project of Science and Technology Commission Foundation of Shanghai(No.20520741000)Ningbo 2025 Science and Technology Major Project(No.2019B10068)the Science and Technology Commission of Shanghai(No.20DZ2254900)。
文摘Polyurethane is widely used for its versatility in design and range of performance.Self-healing and recyclable dynamic polyurethane networks have attracted extensive attention due to their potential to extend service life and ensure safety in use,as well as to promote sustainable use of resources.Developing green and environment-friendly methods to obtain this material is an interesting and challenging task,as the majority of current dynamic polyurethane networks utilize the solution polymerization method.The use of solvents makes the processes complicated,harmful to environment,and increase the cost.Poly(oxime-urethanes)(POUs)are emerging dynamic polyurethanes and show great potential in diverse fields,such as biomaterials,hot melt adhesives,and flexible electronics.In this study,we utilized the solubility properties of dimethylglyoxime in raw material poly(ethylene glycol)to prepare POUs through bulk polymerization for the first time.This method is simple,convenient and cost-efficient.Simultaneously,copper ion coordination improves POUs strength and dynamic properties,with mechanical strength up from 0.54 MPa to 1.03 MPa and self-healing recovery rate up from 85.5%to 91.8%,and activation energy down from 119.6 k J/mol to 95.4 k J/mol.To demonstrate the application of this technology,self-healing and stretchable circuits are constructed from this dynamic polyurethane network.
基金supported by National Nature Science Foundation of China(51977079,51607067)the Project of Young Top Talents in Colleges and Universities of Hebei Province(BJ2021096)+1 种基金Youth Elite Scientists Sponsorship Program by Chinese Society for Electrical Engineering(CSEE-YESS-2017002)the Fundamental Research Funds for the Central Universities(2020MS115,2017MS149).
文摘Unexpected ice accumulation tends to cause many problems or even disasters in our daily life.Based on the superior electrothermal and photothermal function of the carbon nanotubes,we introduced a superhydrophobic/electrothermal/photothermal synergistically anti-icing strategy.When a voltage of 15 V was applied to the superhydrophobic sample,the surface could rapidly melt the ice layer(~3 mm thickness)within 530 s at the environmental temperature of-25℃.When the near-infrared light(808 nm)irradiates on the superhydrophobic sample,the ice could be rapidly removed after 460 s.It was found that the superhydrophobicity helps the melted water to roll off immediately,and then solves the re-freeze problem the traditional surfaces facing.Moreover,the ice can be completely melted with 120 s when the superhydrophobic/electrothermal/photothermal synergistically anti-icing strategy was utilized.To improve the mechanical robustness for practical application,both nanoscale carbon nanotubes and microscale carbon powders were utilized to construct hierarchical structure.Then these dual-scale fillers were sprinkled onto the semi-cured elastomer substrate to prepare partially embedded structure.Both hierarchical structure and partially embedded structure were obtained after completely curing the substrate,which imparts excellent abrasion resistance(12.50 kPa,16.00 m)to the prepared sample.Moreover,self-healable poly(urea–urethane)elastomer was introduced as the substrate.Thus,the cutted superhydrophobic sample can be mended by simply contacting at room temperature.
文摘Flexible conductive fibers are essential for wearable electronics and smart electronic textiles.However,in complex operating conditions,conductive fibers will inevitably fracture or damage.Herein,we have developed an elastic conductive self-healable fiber(C-SHF),of which the electrical and mechanical properties can efficiently heal in a wide operating range,including room temperature,underwater,and low temperature.This advantage can be owed to the combination of reversible covalent imine bond and disulfide bond,as well as the instantaneous self-healing ability of liquid metal.The C-SHF,with stretchability,conductivity stability,and universal self-healing properties,can be used as an electrical signal transmission line at high strain and under different operating conditions.Besides,C-SHF was assembled into a double-layer capacitor structure to construct a self-healable sensor,which can effectively respond to pressure as a wearable motion detector.
文摘The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible supercapacitor.For this purpose,the electroconductive polymer brushes(EPB)was elaborated.The synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the EPBs.Electroconducting films were prepared by casting of EPB solution with subsequent drying.Investigation of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA samples.It was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.
基金supported by Budget Bureau, The Prime Minister’s Office, Thailand (the strategic program on value creation agriculture for Kasetsart University in the fiscal year 2024)。
文摘Crosslinking natural rubber (NR) and styrene butadiene rubber (SBR) composites with carbon black (CB) have been utilized in the tire tread industry.A sulfur-based lightly crosslinker can potentially enhance the self-healing capabilities of rubber.Moreover,the rubber composites were studied for non-covalent interactions between the benzene rings of SBR and CB.In this research,rubber samples were prepared,and their structure was investigated using Fourier transform infrared (FTIR),and Raman spectroscopy.The red shift in Raman spectroscopy confirmed noncovalent interaction or hydrophobic interaction between SBR and CB in NR/SBR composites exposed to CB due to environmental change.The differential scanning calorimetry (DSC) thermograms showed that NR and SBR were incompatible.Additionally,the mechanical properties of these rubber blends were enhanced as the proportion of NR increased.The maximum self-healing performance reached 40%for the formulation containing 25 phr NR and 75 phr SBR,which also saved energy with low chain end movements.Therefore,these composites could be utilized as a semi-empirical model for studying crosslinked rubber blends,specifically in the rubber tire industry.
基金supported by the Petro China Innovation Foundation(No.2014D-5006-0201)the National Natural Science Foundation of China(Nos.51473152 and 51573174)the Fundamental Research Funds for the Central Universities(Nos.WK2060200012,WK3450000001)
文摘Self-healable polyacrylamide-based hydrogels were prepared at room temperature via a one-step emulsion copolymerization of acrylamide（AM）,dodecyl 2-methacryIate（DM）,and 5-acetylaminopentyl acrylate（AAPA） using sodium dodecyl sulfonate（SDS） as the emulsifier and ammonium persulfate（APS）as the initiator.The produced linear multi-block copolymer chains are composed of randomly-linked hydrophilic polyacrylamide segments（PAM） and hydrophobic segments constituted by DM and AAPA units（P（DM-co-AAPA））.The P（DM-co-AAPA） segments will self-aggregate into hydrophobic microdomains during the polymerization process driven by the hydrophobic interactions,and finally separate from water phase,acting as the crosslinks and leading to the formation of strong hydrogels with a storage modulus as high as 400 Pa.These hydrophobic microdomains will be dissolved in water when the temperature increases to 70℃,resulting in a temperature-responsive reversible sol-gel transition of the prepared hydrogels.Furthermore,the prepared hydrogels have excellent self-healing ability.The broken hydrogels can be automatically healed into a body with a same strength within 2-min＇s contact.This work provides a new simple way to prepare reversible physical crosslinked hydrogel with high strength and self-healing efficiency.
基金National Key Research and Development Program of China(Grant No.2022YFB3808800)the National Nature Science Foundation of China(Grant No.52272084,Grant No.52202101,Grant No.52203002,Grant No.52072177)+2 种基金the National Science Foundation of Jiangsu Province(Grant No.BK20220430)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Grant No.22KJB430007)the Fundamental Research Funds for the Central Universities(Grant No.2023102003,Grant No.30924010202).
文摘Robust and reliable piezo-ionic materials that are both crack resistant and selfhealable like biological skin hold great promise for applications inflexible electronics and intelligent systems with prolonged service lives.However,such a combination of high toughness,superior crack resistance,autonomous self-healing and effective control of ion dynamics is rarely seen in artificial iontronic skin because these features are seemingly incompatible in materials design.Here,we resolve this perennial mismatch through a molecularly engineered strategy of implanting carboxyl-functionalized groups into the dynamic hard domain structure of synthesized poly(urethane-urea).This design provides an ultra-high fracture energy of 211.27 kJ m^(-2)that is over 123.54 times that of tough human skin,while maintaining skin-like stretchability,elasticity,and autonomous self-healing with a 96.40%healing efficiency.Moreover,the carboxyl anion group allows the dynamic confinement of ionic fluids though electrostatic interaction,thereby ensuring a remarkable pressure sensitivity of 7.03 kPa^(-1)for the tactile sensors.As such,we successfully demonstrated the enormous potential ability of this skin-like piezoionic sensor for biomedical monitoring and robotic item identification,which indicates promising future uses in flexible electronics and human-machine interactions.
基金supported by the National Natural Science Foundation of China(52173117,52073049,52473004,52303178,51673162,15201719)the China Postdoctoral Science Foundation(2023M740585)+4 种基金the Natural Science Foundation of Shanghai(22ZR1400700)the Shanghai Rising-Star Program(21QA1400200),the Shanghai Sailing Program(23YF1400500)the Science and Technology Commission of Shanghai Municipality(20DZ2254900)the Research Grants Council Collaborative Research Fund(C1017-22GF)the Fundamental Research Funds for the Central Universities(2232024G-12).
文摘For room temperature self-healing triboelectric nanogenerators(TENGs);the inherent contradiction between mechanical strength and self-healing properties was an urgent problem to be solved.Based on the phenol-carbamate bond;this paper proposed a strategy to design a new molecular structure and coordinate the triple dynamic bonds;which provided a feasible strategy to solve this contradiction.With polytetramethylene ether glycol(M_(n)=1;000)as the soft segment in the main chain of polyurethane(PU);meanwhile methylene diphenyl diisocyanate and 4,4'-dihydroxybiphenyl(BP)as the hard segment and chain extension agent;respectively;the combination of tetrad benzene ring endowed the resultant 4BP-PU withπ-πinteraction.The effective reversible dissociation and association with hydrogen bond not only bestowed 4BP-PU with high mechanical strength(16.14 MPa);but also promoted high self-healing efficiency(94.8%)at room temperature.4BP-PU was selected as the elastic substrate between polydimethylsiloxane and copper sheet to prepare a self-healing TENG to collect energy from natural motion.Consequently;the rational molecular structure design provided new ideas for developing self-healing materials and fabricating energy harvest electronics.
基金supported by MAOF Fellowship from the Council for Higher Education,Israel.K.G.acknowledges Aly Kaufman Fellowship Trust for partial support of his fellowshipsupported by the Israel Science Foundation and the Technion’s president grant,and we thank them for that.
文摘Bacterial wound infections are a growing challenge in healthcare,posing severe risks like systemic infection,organ failure,and sepsis,with projections predicting over 10 million deaths annually by 2050.Antibacterial hydrogels,with adaptable extracellular matrix-like features,are emerging as promising solutions for treating infectious wounds.However,the antibacterial properties of most of these hydrogels are largely attributed to extrinsic agents,and their mechanisms of action remain poorly understood.Herein we introduce for the first time,modified imidazolidinyl urea(IU)as the polymeric backbone for developing tissue-like antibacterial hydrogels.As-designed hydrogels behave tissue-like mechanical features,outstanding antifreeze behavior,and rapid self-healing capabilities.Molecular dynamics(MD)simulation and density functional theory(DFT)calculation were employed to well-understand the extent of H-bonding and metal-ligand coordination to finetune hydrogels’properties.In vitro studies suggest good biocompatibility of hydrogels against mouse fibroblasts&human skin,lung,and red blood cells,with potential wound healing capacity.Additionally,the hydrogels exhibit good 3D printability and remarkable antibacterial activity,attributed to concentration dependent ROS genera-tion,oxidative stress induction,and subsequent disruption of bacterial membrane.On top of that,in vitro biofilm studies confirmed that developed hydrogels are effective in preventing biofilm formation.Therefore,these tissue-mimetic hydrogels present a promising and effective platform for accelerating wound healing while simulta-neously controlling bacterial infections,offering hope for the future of wound care.
基金supported by the National Natural Science Foundation of China(21975107)the Natural Science Foundation of Jiangsu Province(BK2019020945)financial support from the PolyU Departmental General Research Fund(P0046213)。
文摘Self-healing polyurethane-elastomers are highly desired in various fields.However,there is often a trade-off between mechanical properties and dynamic self-healing due to the mutually exclusive mechanism.Herein,we develop a self-healable and mechanically robust poly(oxime-urethane)elastomer(Zn-DAPU)to circumvent this inherent trade-off by incorporating zincpyridinyl cross-links into the hydrogen bonding and dynamic oxime-urethane supramolecular-covalent hybrid network.Benefiting from the synergistic strengthening of H-bonding and coordinate interactions,Zn-DAPU network performs tunable toughness with metal ion concentration change,which improves 345.2%and reaches 82.2 MJ m^(-3),with robust tensile strength of 22.8 MPa,Young's modulus of 37.1 MPa,and satisfactory elongation of 815.7%.The healing efficiency can be reached at 91.7%with a restored toughness of 75.4 MJ m^(-3)at 80℃for 10 h.Furthermore,zinc-contained networks exhibit photolysis behavior due to the homolytic cleavage of N-O bonds in oxime-urethane moieties,which can be functionalized further with fluorescamine as the specific information encryption coating with quick response codes(QRs)upon polyester fabric.This work provides valuable guidance towards the development of high-performance self-healing polyurethane and wearable functional materials.
基金supported by a Japan Society for the Promotion of Science(JSPS)Grant-in-Aid for Specially Promoted Research(grant no.23H05408)on“Solid-State Materials Science of Supramolecular Polymers and Their Applications”and also the RIKEN TRIP Initiative Polymer Chemistry for T.A.
文摘In 2018,we reported that poly(ether thiourea)(PTUEG_(3)),a glassy polymer with a glass transition temperature(T_(g))of 27℃,can self-heal at 12℃,which updated the preconception that a mechanically robust glassy polymer cannot self-heal below its Tg.Herein,we report a new and even better selfhealable glassy polymer,poly(thioether thiourea)(PTU(C_(2)SSC_(2))),by combining thiourea and alkyl disulfide.This polymer possibly takes advantage of its metathesis-active disulfide bonds,and in fact,it selfhealed even at 10℃ despite the fact that its glass transition temperature(T_(g))was 45℃,which is obviously higher than that of PTUEG3.Although its variant PTU(C_(2)SCCSC_(2))without any-S-S-bonds self-healed at 0℃,its Tg was also low at 25℃.When a disulfide ether unit was copolymerized with a ether thiourea unit,the resulting copolymers showed an distinctly lowered self-healing temperature even though their copolymer sequences contained a T_(g)-raising dicyclohexylmethane unit.PTU(C_(2)SSC_(2))is much less hygroscopic than PTUEG_(3) and therefore can be utilized even in high humidity without plasticization.
基金Funded by the National Key R&D Program of China(No.2023YFC3806100)the National Nature Science Foundation of China(Nos.52278269,52278268,52178264,and 52108238)+2 种基金the Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)the Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)the Joint Research Center of China and Foreign Countries Special Fund of Tianjin Innovation Platform(No.24PTLYHZ00240)。
文摘Sporosarcina pasteurii was employed as the strain,with an in-situ magnetization construction,to obtain magnetic microorganisms and oriented self-healing mortar specimens based on them.The magnetic field was used to achieve the directional migration of magnetic microorganisms during the oriented selfhealing of mortar cracks,improving the rate of self-healing of cracks.The experimental results demonstrate that the magnetic microorganisms are composed of Fe_(3)O_(4)nanosheets attached to the surface of Sporosarcina pasteurii,whose mineralization products are comprised of vaterite primarily.Compared with the pure microbial group,the magnetic microbial group exhibits a faster repair rate,shortening the repair time required to achieve an area repair efficiency of over 90%from 28 days to 14 days,thereby doubling the repair rate.Meanwhile,the area repair efficiency of the magnetic microbial group at 7,14,and 28 days are increased by 50.3%,11.2%,and 4.6%,respectively,compared to the pure microbial group,which are due to the magnetic microorganisms'superior directional migration and mineralization ability,exceeding that of the ordinary microorganisms.
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Funded by the National Key R&D Program of China(No.2023YFC3806100)the National Nature Science Foundation of China(No.52278269,52278268)+2 种基金the Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)the Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)the Joint Research Center of China and Foreign Countries Special Fund of Tianjin Innovation Platform(No.24PTLYHZ00240)。
文摘We mixed Bacillus subtilis and brewing yeast to prepare composite microbial self-healing materials,and studied the self-healing effect of composite microorganisms in mortar cracks of different widths and cracking ages.The experimental results show that the performance and self-healing effect of composite micro-organisms are significantly better than those of single microorganisms.For cracks with widths of 0.2-0.4 mm,the repair effect of the composite microorganisms at 28 days is 42.7%and 71.2%higher than that of pure Bacillus and pure yeast,respectively.The repairing rate of the area with the widths of the cracks of 0.2-0.4,0.4-0.6,and 0.6-0.8 mm are 100%,77.3%,and 53.4%,respectively.The area repair rates corresponding to cracking ages of 56,90,and 180 days are 73.3%,55.4%,and 30.8%,respectively.
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.
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.
