Realizing multiple locked shapes in pre-oriented liquid crystal elastomers(LCEs)is highly desired for diversifying deformations and enhancing multi-functionality.However,conventional LCEs only deform between two shape...Realizing multiple locked shapes in pre-oriented liquid crystal elastomers(LCEs)is highly desired for diversifying deformations and enhancing multi-functionality.However,conventional LCEs only deform between two shapes for each actuation cycle upon liquid crystal-isotropic phase transitions induced by external stimuli.Here,we propose to regulate the actuation modes and the locked shapes of a pre-orientated epoxy LCE by combining dynamic covalent bonds with cooling-rate-mediated control.The actuation modes can be adjusted on demand by exchange reactions of dynamic covalent bonds.Derived from the established actuation modes,such as elongation,bending,and spiraling,the epoxy LCE displays varied locked shapes at room temperature under different cooling rates.Various mediums are utilized to control the cooling rate,including water,silicone oil,and copper plates.This approach provides a novel way for regulating the actuation modes and locked shapes of cuttingedge intelligent devices.展开更多
Covalent adaptable networks(CANs),comprising polymer networks crosslinked by dynamic covalent bonds(DCBs),have garnered considerable attention as sustainable materials.Mastering the stress relaxation of CANs is essent...Covalent adaptable networks(CANs),comprising polymer networks crosslinked by dynamic covalent bonds(DCBs),have garnered considerable attention as sustainable materials.Mastering the stress relaxation of CANs is essential for controlling their viscoelastic properties.An unexpected acceleration of stress relaxation has been observed in CANs containing dual dynamic bonds.The dynamic behavior of the second dynamic bonds can accelerate stress relaxation and lower the relaxation activation energy of dual dynamic CANs compared to analogous CANs that rely on only one type of DCB.These findings complement current approaches that utilize catalysts or adjust network parameters.In this minireview,we summarize the synergistic acceleration effects in various CANs containing dual dynamic bonds.We classify these effects based on the second dynamic bonds,including noncovalent bonds,mechanical bonds,and the second DCBs.We also discuss the mechanisms behind this synergy.Finally,we highlight the challenges and offer perspectives on harnessing the synergistic effects of these dual dynamic systems to expand the chemistry and applications of CANs.展开更多
Covalent adaptive networks(CANs)are capable of undergoing segment rearrangement after being heated,which endows the materials with excellent self-healing and reprocessing performance,providing an efficient solution to...Covalent adaptive networks(CANs)are capable of undergoing segment rearrangement after being heated,which endows the materials with excellent self-healing and reprocessing performance,providing an efficient solution to the environment pollution caused by the plastic wastes.The main challenge remains in developing CANs with both excellent reprocessing performance and creep-resistance property.In this study,a series of CANs containing dynamic covalent benzopyrazole-urea bonds were developed based on the addition reaction between benzopyrazole and isocyanate groups.DFT calculation confirmed that relatively low dissociation energy is obtained through undergoing a five-member ring transition state,confirming excellent dynamic property of the benzopyrazole-urea bonds.As verified by the FTIR results,this nice dynamic property can be well maintained after incorporating the benzopyrazole-urea bonds into polymer networks.Excellent self-healing and reprocessing performance is observed by the 3-ABP/PDMS elastomers owing to the dynamic benzopyrazole-urea bonds.Phase separation induced by the aggregation of the hard segments locked the benzopyrazole-urea bonds,which also makes the elastomers display excellent creep-resistance performance.This hard phase locking strategy provides an efficient approach to design CANs materials with both excellent reprocessing and creep-resistance performance.展开更多
Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor m...Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor mechanical property and weaken the pH-responsive capability.In this work,a carbon dotsenhanced pH-responsive lubricating hydrogel is developed by combining a pH-responsive section of dynamic PVA-borax network into a PAAm covalent polymer network.The formed hydrogel presents a partial gel-sol transition under controlled pH environments.At low pH environments(<6.0),the formed lubricating layer originated from dynamic disassembly of PVA-borax hydrogel,and brings the lubricating properties on the hydrogel surface.Moreover,the mechanical strength and lubrication properties are well promoted by introducing the carbon dots into the hydrogel,the blue sol layer can be observed more visually under the fluorescence microscope.The pH-response also exhibits well reversibility.The prepared hydrogel broadens the idea for designing pH-responsive soft materials for soft lubricating actuator or robot.展开更多
Efficient intracellular delivery of protein drugs is critical for protein therapy.The combination of protein drugs with chemotherapeutics represents a promising strategy in enhancing anti-cancer effect.However,co-deli...Efficient intracellular delivery of protein drugs is critical for protein therapy.The combination of protein drugs with chemotherapeutics represents a promising strategy in enhancing anti-cancer effect.However,co-delivery systems for efficient delivery of these two kinds of drugs are still lacking because of their different properties.Herein,we show a well-designed delivery system based on dynamic covalent bond for efficient intracellular co-delivery of ribonuclease A(RNase A)and doxorubicin(DOX).Two polymers,PEG-b-P(Asp-co-AspDA)and PAE-b-P(Asp-co-AspPBA),and two 2-acetylphenylboronic acid(2-APBA)-functionalized drugs,2-APBA-RNase A and 2-APBA-DOX,self-assemble into mixed-shell nanoparticles(RNase A/DOX@MNPs)via dynamic phenylboronic acid(PBA)-catechol bond between PBA and dopamine(DA)moieties.The PBA-catechol bond endows the nanoparticles with high stability and excellent stimulus-responsive drug release behavior.Under the slight acidic environment at tumor tissue,RNase A/DOX@MNPs are positively charged,promoting their endocytosis.Upon cellular uptake into endosome,further protonation of PAE chains leads to the rupture of endosomes because of the proton sponge effect and the cleavage of PBA-catechol bond promotes the release of two drugs.In cytoplasm,the high level of GSH removed the modification of 2-APBA on drugs.The restored RNase A and DOX show a synergistic and enhanced antic-cancer effect.This system may be a promising platform for intracellular co-delivery of protein drugs and chemotherapeutics.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
New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms.This work reports the facile synthesis of antimicrobial dynamic covalent...New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms.This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks(aDCNs)composing antibiotics bearing multiple primary amines,polyphenols,and a cross-linker acylphenylboronic acid.Mechanistically,the iminoboronate bond drives the formation of aDCNs,facilitates their stability,and renders them highly responsive to stimuli,such as low pH and high H2O2 levels.Besides,the representative A1B1C1 networks,composed of polymyxin B1(A1),2-formylphenylboronic acid(B1),and quercetin(C1),inhibit biofilm formation of drug-resistant Escherichia coli,eliminate the mature biofilms,alleviate macrophage inflammation,and minimize the side effects of free polymyxins.Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model.The facile synthesis,excellent antimicrobial performance,and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.展开更多
Life,defined as the specific form of substance,is an integration of aggregates at various scales,ranging from single molecules to tissues.However,these building blocks of common aggregates are usually recognized as co...Life,defined as the specific form of substance,is an integration of aggregates at various scales,ranging from single molecules to tissues.However,these building blocks of common aggregates are usually recognized as confining at the microscopic level,while there are few studies focusing on macroscopic building blocks for aggregates.Fluorescent gels,as the important macroscopic building blocks,are drawing researchers’attention on account of their extraordinary fluorescence as well as soft material properties.Inspired by nature,fluorescent gels can be aggregated through interfacial adhesion.According to the driving forces for interfacial adhesion,a series of aggregates of fluorescent gels(AFGs)was summarized,including H-bond,metal coordinations,host-guest interactions,hydrophobic interactions,electrostatic interactions,dynamic covalent bonds as well as multiple driving forces.These AFGs own dynamic assembled behaviors and rich stimuli responsiveness,which could be applied to information storage,sensing,biomedical systems,and so on.The authors anticipate this review can accelerate the development of aggregate science,especially based on macroscopic building blocks.展开更多
Sulfur-containing dynamic polymers had attracted significant attention due to their unique chemical structures with high reversibility.Utilizating sulfur, an inexpensive industrial waste product, to synthesize dynamic...Sulfur-containing dynamic polymers had attracted significant attention due to their unique chemical structures with high reversibility.Utilizating sulfur, an inexpensive industrial waste product, to synthesize dynamic polysulfide polymers through reverse vulcanization has been a notable approach. However, this method required high temperatures and resulted in the release of unpleasant oders. In this study, we presented a robust method for the preparation of sulfur-rich polymers with dynamic polysulfide bonds from elemental sulfur and inexpensive epoxide monomers via a one-pot strategy at the mild room temperature. Different types of polysulfide molecules and polymers were synthesized by reacting various epoxide compounds with sulfur, along with the investigation of their structures and dynamic behaviors. It was noteworthy that the obatined polymers prepared from m-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline and elemental sulfur exhibit multiple dynamic behaviors, including polysulfide metathesis and polysulfide-thiol exchange, enabling their rapid stress relaxation, self-healing, reprocessing and degradable properties of the cross-linked polymer. More importantly, the hydroxyl groups at the side chains from epoxide ring opening exhibited potential transesterification. This work provided a facile strategy for designing dynamic sulfur-rich polymers via a mild synthesis route.展开更多
Oxime-urethane bond featuring with high reversibility even at room temperature and multiple reactivity is an emerging dynamic covalent bond,and has shown great potential for self-healing polymers,which are one of the ...Oxime-urethane bond featuring with high reversibility even at room temperature and multiple reactivity is an emerging dynamic covalent bond,and has shown great potential for self-healing polymers,which are one of the most attractive development directions for next generation of polymeric materials.In this review,recent progresses on the oxime-urethane-based self-healing polymers,including their designs and applications in diverse fields such as biomedicine,flexible electronics,soft robots,3D printing,protective materials,and adhesives,are summarized,and outlooks on the future development of this field are discussed.展开更多
In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced ...In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced into polymer materials for different functions.These functional polymer materials have brought new opportunities for sustainable development.In this review,we provide an overview of various functions endowed by DCBs in polymer materials,including self-healing,chemical recycling,and shape controlling.Particularly,we pay much attention to the three-dimensional(3D)shape reconfiguration/programming,surface patterning,and reversible actuation.In addition,we also give the current issues,challenges,and opportunities on DCBs-containing materials and point out its developing directions in the future.展开更多
Polylactide(PLA)has often been blended with biodegradable poly(butylene adipate-co-terephthalate)(PBAT)to improve its toughness.However,the strength and heat resistance of PLA are always sacrificed.Herein,exchangeable...Polylactide(PLA)has often been blended with biodegradable poly(butylene adipate-co-terephthalate)(PBAT)to improve its toughness.However,the strength and heat resistance of PLA are always sacrificed.Herein,exchangeable hydroxyl-ester crosslinks are constructed in PLA/PBAT blends by successively introducing a tertiary amine-containing polyol,bis-(2-hydroxyethyl)amino-tris(hydroxymethyl)methane(BTM)and 4,4’-diphenylmethane diisocyanate(MDI)via reactive blending.BTM can react with both PLA and PBAT by transesterification,generating PLA or PBAT chains with terminal or pendant hydroxyl groups,which can then react with MDI to form networks.With internal catalysis of tertiary amine moiety in BTM,transesterification between the residual hydroxyl groups and ester bonds can occur at high temperatures,endowing the PLA/PBAT network with vitrimeric properties.Owning to the transesterification and chain extension reactions with MDI between PLA and PBAT,the interfacial adhesion is greatly improved.As a result of the excellent interfacial adhesion and the network structure,the prepared PLA/PBAT blends show greatly enhanced heat resistance and toughness(more than 40 times that of PLA)while maintaining high stiffness comparable to PLA.Furthermore,the prepared PLA/PBAT blends exhibit promising reconfigurable shape memory behavior.The present work provides a new and facile way to achieve high-performance and functional biodegradable polymeric materials.展开更多
Thioredoxin Reductase(TrxR)plays a pivotal role in defending cells against reactive oxygen species(ROS)and maintaining a reduced intracellular environment.It has been discovered that TrxR is elevated significantly in ...Thioredoxin Reductase(TrxR)plays a pivotal role in defending cells against reactive oxygen species(ROS)and maintaining a reduced intracellular environment.It has been discovered that TrxR is elevated significantly in human cancer,evidenced by its association with the promotion of tumor cell proliferation,inhibiting tumor cell apoptosis,as well as enhancing tumor drug resistance.Hence,finding highly selective inhibitors of TrxR is urgently needed.Herein,we developed a selenium-containing small molecule(EbD),which had two Se–N bonds.Under reduction conditions,the two Se–N bonds reacted with Se–H bond and S–H bond in TrxR to form new Se–Se bond and Se–S bonds,respectively.Subsequently,the newly formed bonds were able to disrupt the thioredoxin(Trx)reduction catalytic cycle,and thus,inhibited the TrxR activity irreversibly,which resulted in the collapse of the antioxidant system.As a consequence,ROS levels elevated that triggered cancer cell apoptosis.This strategy,based on selenium-containing dynamic covalent bonds,provides a new avenue for cancer therapy via targeting TrxR.展开更多
In this paper, dynamic covalent bond has been employed to construct supra-amphiphile of carbohydrate for the first time. In neutral environment, the molecule was fabricated by reacting a hydrophobic building block bea...In this paper, dynamic covalent bond has been employed to construct supra-amphiphile of carbohydrate for the first time. In neutral environment, the molecule was fabricated by reacting a hydrophobic building block bearing benzoic aldehyde with a hydrophilic building block bearing hydrazine to form a sugar-containing supra-amphiphile based on acylhydrazone bond, The obtained azobenzene- galactopyranoside （Azo-Gal） supra-amphiphile self-assembled to fibrillar structure in water, which showed dual responses to UV light and pH.展开更多
Recyclability of thermosetting polymers and their composites is a challenge for alleviating environmental pollution and resource waste.In this study,solvent-recyclable thermosetting polyimide(PI)and its composite were...Recyclability of thermosetting polymers and their composites is a challenge for alleviating environmental pollution and resource waste.In this study,solvent-recyclable thermosetting polyimide(PI)and its composite were successfully synthesized.The tensile strength,elongation at break,and Young’s modulus of PI are 108.70±7.29 MPa,19.35%±3.89%,and 2336.42±128.00 MPa,respectively.The addition of reduced graphene oxide(RGO)not only enhances the mechanical properties of PI but also endows it with excellent tribological properties.The PI illustrates a high recycling efficiency of 94.15%,but the recycled composite exhibits inferior mechanical properties.The recycling and utilization of PI and its composite are realized through imine bonds(-C=N),which provides new guidance for solving the problem of environmental pollution and resource waste and is potential application in the field of sustainable tribology.展开更多
Despite extensive efforts in designing and preparing switchable underwater adhesives,it is not easy to regulate the underwater adhesion strength locally and remotely.Here,we design and synthesize photoreversible copol...Despite extensive efforts in designing and preparing switchable underwater adhesives,it is not easy to regulate the underwater adhesion strength locally and remotely.Here,we design and synthesize photoreversible copolymer of poly[dopamine methacrylamide-co-methoxyethyl-acrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin].Due to the dynamic formation and breaking of chemical crosslinking networks within the smart adhesives,the material shows widely tunable adhesion strength from∼150 to∼450 kPa and long-range reversible maneuverability under orthogonal 254 and 365 nm ultraviolet light stimulation via the coumarin dimerization and cycloreversion.Moreover,the adhesive exhibits good circulation performance and stability in an acid–base environment.It also demonstrated that the bolt can be coated with the smart adhesive material for on-demand bonding.This design principle opens the door to the development of remotely controllable high-performance smart underwater adhesives.展开更多
Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electric...Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electrical devices,and soft robotics.However,existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness,complex and time-consuming preparation process,unhealable,and non-reconfiguration.Herein,we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles.Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer(interfacial toughness:390 J m^(-2)),endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration.Moreover,this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration.Taking advantage of the aforementioned features,we readily constructed a multi-module,self-healing,self-powered,and realtime monitoring of personal status integrated elastic electronics,which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.展开更多
The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks,thereby meeting the sustainable requirements for polymer recycling.However,the mechanical properties of many...The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks,thereby meeting the sustainable requirements for polymer recycling.However,the mechanical properties of many materials often decline significantly upon reprocessing due to side reactions caused by harsh processing conditions.In this work,we find that the aromatic dithiocarbamate bond can undergo dissociation under mild conditions without the need for a catalyst,enabling the efficient reprocessing of the corresponding polydithiourethane.As a consequence,the mechanical properties of the polydithiourethane can be largely preserved after reprocessing.The discovery of this dynamic chemistry is anticipated to broaden the potential for material design in dynamic covalent polymer networks.展开更多
The"solid-liquid"behavior of vitrimers have not been systematically investigated.Herein,a series of"solid-liquid"vitrimers bearing varying contents of dynamic boronic ester bonds were synthesized v...The"solid-liquid"behavior of vitrimers have not been systematically investigated.Herein,a series of"solid-liquid"vitrimers bearing varying contents of dynamic boronic ester bonds were synthesized via thiol-ene click reactions.These vitrimers allow for flexibile modulation of their network structures and thus show a range of intriguing properties including high stretchability,flexible transition from elasticity to plasticity,strong strain rate dependence,and solid-liquid performance.The dynamic association rate of boronic ester bonds within these vitrimers could be apparently accelerated via increasing the content of boronic ester,which could be used to shape-program the flat vitrimer films into various complex 3D structures just with external force.Materials with such versatile dynamic behavior may open up a range of new applications.展开更多
The isomerization of covalent organic frameworks(COFs) materials is still a mysterious and attractive topic. Diversified monomer structures are still urgently needed to explore the in-depth mechanism of isomerization ...The isomerization of covalent organic frameworks(COFs) materials is still a mysterious and attractive topic. Diversified monomer structures are still urgently needed to explore the in-depth mechanism of isomerization in these special COFs. This work provides a new D2h monomer for the construction of [D2h+C2] 2D COFs isomers. A new D2h monomer adopted here was proven to tend to form a single pore framework structure.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22375114)。
文摘Realizing multiple locked shapes in pre-oriented liquid crystal elastomers(LCEs)is highly desired for diversifying deformations and enhancing multi-functionality.However,conventional LCEs only deform between two shapes for each actuation cycle upon liquid crystal-isotropic phase transitions induced by external stimuli.Here,we propose to regulate the actuation modes and the locked shapes of a pre-orientated epoxy LCE by combining dynamic covalent bonds with cooling-rate-mediated control.The actuation modes can be adjusted on demand by exchange reactions of dynamic covalent bonds.Derived from the established actuation modes,such as elongation,bending,and spiraling,the epoxy LCE displays varied locked shapes at room temperature under different cooling rates.Various mediums are utilized to control the cooling rate,including water,silicone oil,and copper plates.This approach provides a novel way for regulating the actuation modes and locked shapes of cuttingedge intelligent devices.
基金the financial support of the NSFC/China(grant nos.22071152 and 22122105)the Natural Science Foundation of Shanghai(grant nos.22dz1207603 and 20ZR1429200)+2 种基金supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(SNZJU-SIAS-006)the Shuguang Program of Shanghai Education Development Foundationthe Shanghai Municipal Education Commission(22SG11).
文摘Covalent adaptable networks(CANs),comprising polymer networks crosslinked by dynamic covalent bonds(DCBs),have garnered considerable attention as sustainable materials.Mastering the stress relaxation of CANs is essential for controlling their viscoelastic properties.An unexpected acceleration of stress relaxation has been observed in CANs containing dual dynamic bonds.The dynamic behavior of the second dynamic bonds can accelerate stress relaxation and lower the relaxation activation energy of dual dynamic CANs compared to analogous CANs that rely on only one type of DCB.These findings complement current approaches that utilize catalysts or adjust network parameters.In this minireview,we summarize the synergistic acceleration effects in various CANs containing dual dynamic bonds.We classify these effects based on the second dynamic bonds,including noncovalent bonds,mechanical bonds,and the second DCBs.We also discuss the mechanisms behind this synergy.Finally,we highlight the challenges and offer perspectives on harnessing the synergistic effects of these dual dynamic systems to expand the chemistry and applications of CANs.
基金supported by the National Natural Science Foundation of China(No.52173113)。
文摘Covalent adaptive networks(CANs)are capable of undergoing segment rearrangement after being heated,which endows the materials with excellent self-healing and reprocessing performance,providing an efficient solution to the environment pollution caused by the plastic wastes.The main challenge remains in developing CANs with both excellent reprocessing performance and creep-resistance property.In this study,a series of CANs containing dynamic covalent benzopyrazole-urea bonds were developed based on the addition reaction between benzopyrazole and isocyanate groups.DFT calculation confirmed that relatively low dissociation energy is obtained through undergoing a five-member ring transition state,confirming excellent dynamic property of the benzopyrazole-urea bonds.As verified by the FTIR results,this nice dynamic property can be well maintained after incorporating the benzopyrazole-urea bonds into polymer networks.Excellent self-healing and reprocessing performance is observed by the 3-ABP/PDMS elastomers owing to the dynamic benzopyrazole-urea bonds.Phase separation induced by the aggregation of the hard segments locked the benzopyrazole-urea bonds,which also makes the elastomers display excellent creep-resistance performance.This hard phase locking strategy provides an efficient approach to design CANs materials with both excellent reprocessing and creep-resistance performance.
基金supported by the National Natural Science Foundation of China(No.22175075).
文摘Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor mechanical property and weaken the pH-responsive capability.In this work,a carbon dotsenhanced pH-responsive lubricating hydrogel is developed by combining a pH-responsive section of dynamic PVA-borax network into a PAAm covalent polymer network.The formed hydrogel presents a partial gel-sol transition under controlled pH environments.At low pH environments(<6.0),the formed lubricating layer originated from dynamic disassembly of PVA-borax hydrogel,and brings the lubricating properties on the hydrogel surface.Moreover,the mechanical strength and lubrication properties are well promoted by introducing the carbon dots into the hydrogel,the blue sol layer can be observed more visually under the fluorescence microscope.The pH-response also exhibits well reversibility.The prepared hydrogel broadens the idea for designing pH-responsive soft materials for soft lubricating actuator or robot.
基金This work was financially supported by the National Key R&D Program of China(Nos.2022YFA1205703 and 2022YFA1205702)the National Natural Science Foundation of China(Nos.51773099,51933006 and 52103183)Haihe Laboratory of Sustainable Chemical Transformations(No.YYJC202102).
文摘Efficient intracellular delivery of protein drugs is critical for protein therapy.The combination of protein drugs with chemotherapeutics represents a promising strategy in enhancing anti-cancer effect.However,co-delivery systems for efficient delivery of these two kinds of drugs are still lacking because of their different properties.Herein,we show a well-designed delivery system based on dynamic covalent bond for efficient intracellular co-delivery of ribonuclease A(RNase A)and doxorubicin(DOX).Two polymers,PEG-b-P(Asp-co-AspDA)and PAE-b-P(Asp-co-AspPBA),and two 2-acetylphenylboronic acid(2-APBA)-functionalized drugs,2-APBA-RNase A and 2-APBA-DOX,self-assemble into mixed-shell nanoparticles(RNase A/DOX@MNPs)via dynamic phenylboronic acid(PBA)-catechol bond between PBA and dopamine(DA)moieties.The PBA-catechol bond endows the nanoparticles with high stability and excellent stimulus-responsive drug release behavior.Under the slight acidic environment at tumor tissue,RNase A/DOX@MNPs are positively charged,promoting their endocytosis.Upon cellular uptake into endosome,further protonation of PAE chains leads to the rupture of endosomes because of the proton sponge effect and the cleavage of PBA-catechol bond promotes the release of two drugs.In cytoplasm,the high level of GSH removed the modification of 2-APBA on drugs.The restored RNase A and DOX show a synergistic and enhanced antic-cancer effect.This system may be a promising platform for intracellular co-delivery of protein drugs and chemotherapeutics.
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 the National Natural Science Foundation of China(Grant Nos.52203184,22275043,51773099,52293380,and 52293383)Startup Fund of Wenzhou Institute,University of Chinese Academy of Sciences(Grant No.WIUCASQD2021022)+1 种基金Key Laboratory of Functional Polymer Materials,Ministry of Education(Grant No.KLFPM202202)Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province(Grant No.2022E10022).
文摘New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms.This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks(aDCNs)composing antibiotics bearing multiple primary amines,polyphenols,and a cross-linker acylphenylboronic acid.Mechanistically,the iminoboronate bond drives the formation of aDCNs,facilitates their stability,and renders them highly responsive to stimuli,such as low pH and high H2O2 levels.Besides,the representative A1B1C1 networks,composed of polymyxin B1(A1),2-formylphenylboronic acid(B1),and quercetin(C1),inhibit biofilm formation of drug-resistant Escherichia coli,eliminate the mature biofilms,alleviate macrophage inflammation,and minimize the side effects of free polymyxins.Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model.The facile synthesis,excellent antimicrobial performance,and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.
基金National Natural Science Foundation of China,Grant/Award Number:22001087Fundamental Research Funds for the Central Universities,Grant/Award Number:2020kfyXJJS013+1 种基金Open Fund of Hubei Key Laboratory of Material Chemistry and Service Failure,Huazhong University of Science and Technology,Grant/Award Number:2020MCF08Open Research Fund of Key Laboratory of Material Chemistry for Energy Conversion and Storage,Huazhong University of Science and Technology,Ministry of Education,Grant/Award Number:2021JYBKF01。
文摘Life,defined as the specific form of substance,is an integration of aggregates at various scales,ranging from single molecules to tissues.However,these building blocks of common aggregates are usually recognized as confining at the microscopic level,while there are few studies focusing on macroscopic building blocks for aggregates.Fluorescent gels,as the important macroscopic building blocks,are drawing researchers’attention on account of their extraordinary fluorescence as well as soft material properties.Inspired by nature,fluorescent gels can be aggregated through interfacial adhesion.According to the driving forces for interfacial adhesion,a series of aggregates of fluorescent gels(AFGs)was summarized,including H-bond,metal coordinations,host-guest interactions,hydrophobic interactions,electrostatic interactions,dynamic covalent bonds as well as multiple driving forces.These AFGs own dynamic assembled behaviors and rich stimuli responsiveness,which could be applied to information storage,sensing,biomedical systems,and so on.The authors anticipate this review can accelerate the development of aggregate science,especially based on macroscopic building blocks.
基金financially supported by the State Key R&D Program of China (No. 2019YFA0706801)the National Natural Science Foundation of China (No. 52173079)the Fundamental Research Funds for the Central Universities (Nos. xtr052023001 and xzy022024024)。
文摘Sulfur-containing dynamic polymers had attracted significant attention due to their unique chemical structures with high reversibility.Utilizating sulfur, an inexpensive industrial waste product, to synthesize dynamic polysulfide polymers through reverse vulcanization has been a notable approach. However, this method required high temperatures and resulted in the release of unpleasant oders. In this study, we presented a robust method for the preparation of sulfur-rich polymers with dynamic polysulfide bonds from elemental sulfur and inexpensive epoxide monomers via a one-pot strategy at the mild room temperature. Different types of polysulfide molecules and polymers were synthesized by reacting various epoxide compounds with sulfur, along with the investigation of their structures and dynamic behaviors. It was noteworthy that the obatined polymers prepared from m-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline and elemental sulfur exhibit multiple dynamic behaviors, including polysulfide metathesis and polysulfide-thiol exchange, enabling their rapid stress relaxation, self-healing, reprocessing and degradable properties of the cross-linked polymer. More importantly, the hydroxyl groups at the side chains from epoxide ring opening exhibited potential transesterification. This work provided a facile strategy for designing dynamic sulfur-rich polymers via a mild synthesis route.
基金supported by the National Key Research and Development Program of China(No.2021YFC2101804)the National Natural Science Foundation of China(No.21991123)+4 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)Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-dimension Materials(Donghua University)(No.18520750400)Science and Technology Commission of Shanghai Municipality(No.20DZ2254900)the Fundamental Research Funds for the Central Universities,DHU Distinguished Young Professor Program(No.LZA2019001).
文摘Oxime-urethane bond featuring with high reversibility even at room temperature and multiple reactivity is an emerging dynamic covalent bond,and has shown great potential for self-healing polymers,which are one of the most attractive development directions for next generation of polymeric materials.In this review,recent progresses on the oxime-urethane-based self-healing polymers,including their designs and applications in diverse fields such as biomedicine,flexible electronics,soft robots,3D printing,protective materials,and adhesives,are summarized,and outlooks on the future development of this field are discussed.
基金financially supported by the National Natural Science Foundation of China(21734006)the Foundation for Innovative Research Group of the National Natural Science Foundation of China(21821001)。
文摘In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced into polymer materials for different functions.These functional polymer materials have brought new opportunities for sustainable development.In this review,we provide an overview of various functions endowed by DCBs in polymer materials,including self-healing,chemical recycling,and shape controlling.Particularly,we pay much attention to the three-dimensional(3D)shape reconfiguration/programming,surface patterning,and reversible actuation.In addition,we also give the current issues,challenges,and opportunities on DCBs-containing materials and point out its developing directions in the future.
基金financially supported by the National Natural Science Foundation of China(Nos.21975108 and 52103082)Fundamental Research Funds for the Central Universities(No.JUSRP122016)Wuxi"Light of Taihu Lake"Science and Technology Research Plan(Basic Research,No.K20221008).
文摘Polylactide(PLA)has often been blended with biodegradable poly(butylene adipate-co-terephthalate)(PBAT)to improve its toughness.However,the strength and heat resistance of PLA are always sacrificed.Herein,exchangeable hydroxyl-ester crosslinks are constructed in PLA/PBAT blends by successively introducing a tertiary amine-containing polyol,bis-(2-hydroxyethyl)amino-tris(hydroxymethyl)methane(BTM)and 4,4’-diphenylmethane diisocyanate(MDI)via reactive blending.BTM can react with both PLA and PBAT by transesterification,generating PLA or PBAT chains with terminal or pendant hydroxyl groups,which can then react with MDI to form networks.With internal catalysis of tertiary amine moiety in BTM,transesterification between the residual hydroxyl groups and ester bonds can occur at high temperatures,endowing the PLA/PBAT network with vitrimeric properties.Owning to the transesterification and chain extension reactions with MDI between PLA and PBAT,the interfacial adhesion is greatly improved.As a result of the excellent interfacial adhesion and the network structure,the prepared PLA/PBAT blends show greatly enhanced heat resistance and toughness(more than 40 times that of PLA)while maintaining high stiffness comparable to PLA.Furthermore,the prepared PLA/PBAT blends exhibit promising reconfigurable shape memory behavior.The present work provides a new and facile way to achieve high-performance and functional biodegradable polymeric materials.
基金supported financially by the National Basic Research Program of China(2018YFA0208900)the National Natural Science Foundation of China(21734006)+1 种基金China National Funds for Distinguished Young Scientists(21425416)the Funds for Creative Research Groups of China of the National Natural Science Foundation of China(21821001).
文摘Thioredoxin Reductase(TrxR)plays a pivotal role in defending cells against reactive oxygen species(ROS)and maintaining a reduced intracellular environment.It has been discovered that TrxR is elevated significantly in human cancer,evidenced by its association with the promotion of tumor cell proliferation,inhibiting tumor cell apoptosis,as well as enhancing tumor drug resistance.Hence,finding highly selective inhibitors of TrxR is urgently needed.Herein,we developed a selenium-containing small molecule(EbD),which had two Se–N bonds.Under reduction conditions,the two Se–N bonds reacted with Se–H bond and S–H bond in TrxR to form new Se–Se bond and Se–S bonds,respectively.Subsequently,the newly formed bonds were able to disrupt the thioredoxin(Trx)reduction catalytic cycle,and thus,inhibited the TrxR activity irreversibly,which resulted in the collapse of the antioxidant system.As a consequence,ROS levels elevated that triggered cancer cell apoptosis.This strategy,based on selenium-containing dynamic covalent bonds,provides a new avenue for cancer therapy via targeting TrxR.
基金National Natural Science Foundation of China (Nos.91527305,21474020,91227203 and 51322306)the Innovation Program of the Shanghai Municipal Education Commission are acknowledged for their financial support
文摘In this paper, dynamic covalent bond has been employed to construct supra-amphiphile of carbohydrate for the first time. In neutral environment, the molecule was fabricated by reacting a hydrophobic building block bearing benzoic aldehyde with a hydrophilic building block bearing hydrazine to form a sugar-containing supra-amphiphile based on acylhydrazone bond, The obtained azobenzene- galactopyranoside （Azo-Gal） supra-amphiphile self-assembled to fibrillar structure in water, which showed dual responses to UV light and pH.
基金financially supported by the Natural Science Foundation of Gansu Province(Grant No.22JR5RA108)the National Natural Science Foundation of China(Grant No.52205234)+1 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.Y2018457)the Key Program of the Lanzhou Institute of Chemical Physics,CAS(Grant No.KJZLZD-3).
文摘Recyclability of thermosetting polymers and their composites is a challenge for alleviating environmental pollution and resource waste.In this study,solvent-recyclable thermosetting polyimide(PI)and its composite were successfully synthesized.The tensile strength,elongation at break,and Young’s modulus of PI are 108.70±7.29 MPa,19.35%±3.89%,and 2336.42±128.00 MPa,respectively.The addition of reduced graphene oxide(RGO)not only enhances the mechanical properties of PI but also endows it with excellent tribological properties.The PI illustrates a high recycling efficiency of 94.15%,but the recycled composite exhibits inferior mechanical properties.The recycling and utilization of PI and its composite are realized through imine bonds(-C=N),which provides new guidance for solving the problem of environmental pollution and resource waste and is potential application in the field of sustainable tribology.
基金support from the National Natural Science Foundation of China (Nos.22102201,22032006,52205232,and 22072169)the National Key Research and Development Program of China (No.2021YFA0716304)+3 种基金NSAF (No.U2030201)Gansu Province Basic Research Innovation Group Project (No.22JR5RA093)Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing (No.AMGM0717)the Special Research Assistant Project of the Chinese Academy of Sciences.
文摘Despite extensive efforts in designing and preparing switchable underwater adhesives,it is not easy to regulate the underwater adhesion strength locally and remotely.Here,we design and synthesize photoreversible copolymer of poly[dopamine methacrylamide-co-methoxyethyl-acrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin].Due to the dynamic formation and breaking of chemical crosslinking networks within the smart adhesives,the material shows widely tunable adhesion strength from∼150 to∼450 kPa and long-range reversible maneuverability under orthogonal 254 and 365 nm ultraviolet light stimulation via the coumarin dimerization and cycloreversion.Moreover,the adhesive exhibits good circulation performance and stability in an acid–base environment.It also demonstrated that the bolt can be coated with the smart adhesive material for on-demand bonding.This design principle opens the door to the development of remotely controllable high-performance smart underwater adhesives.
基金supported by the National Key Research and Development Program of China(2021YFC2101800,2021YFC2400802)the National Natural Science Foundation of China(52173117,21991123)+1 种基金the Ningbo 2025 Science and Technology Major Project(2019B10068)the Science and Technology Commission of Shanghai(20DZ2254900,20DZ2270800)。
文摘Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electrical devices,and soft robotics.However,existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness,complex and time-consuming preparation process,unhealable,and non-reconfiguration.Herein,we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles.Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer(interfacial toughness:390 J m^(-2)),endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration.Moreover,this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration.Taking advantage of the aforementioned features,we readily constructed a multi-module,self-healing,self-powered,and realtime monitoring of personal status integrated elastic electronics,which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.
基金financially supported by the National Natural Science Foundation of China(Nos.22275162 and 52322307)。
文摘The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks,thereby meeting the sustainable requirements for polymer recycling.However,the mechanical properties of many materials often decline significantly upon reprocessing due to side reactions caused by harsh processing conditions.In this work,we find that the aromatic dithiocarbamate bond can undergo dissociation under mild conditions without the need for a catalyst,enabling the efficient reprocessing of the corresponding polydithiourethane.As a consequence,the mechanical properties of the polydithiourethane can be largely preserved after reprocessing.The discovery of this dynamic chemistry is anticipated to broaden the potential for material design in dynamic covalent polymer networks.
基金supported by the National Natural Science Foundation of China(No.51973023)Sichuan Science and Technology Program(No.2021JDRC0014).
文摘The"solid-liquid"behavior of vitrimers have not been systematically investigated.Herein,a series of"solid-liquid"vitrimers bearing varying contents of dynamic boronic ester bonds were synthesized via thiol-ene click reactions.These vitrimers allow for flexibile modulation of their network structures and thus show a range of intriguing properties including high stretchability,flexible transition from elasticity to plasticity,strong strain rate dependence,and solid-liquid performance.The dynamic association rate of boronic ester bonds within these vitrimers could be apparently accelerated via increasing the content of boronic ester,which could be used to shape-program the flat vitrimer films into various complex 3D structures just with external force.Materials with such versatile dynamic behavior may open up a range of new applications.
基金supported by the National Natural Science Foundation of China(Nos.31202117,31202152)the Natural Science Foundation of Shandong Province,China(No.ZR2020ZD38).
文摘The isomerization of covalent organic frameworks(COFs) materials is still a mysterious and attractive topic. Diversified monomer structures are still urgently needed to explore the in-depth mechanism of isomerization in these special COFs. This work provides a new D2h monomer for the construction of [D2h+C2] 2D COFs isomers. A new D2h monomer adopted here was proven to tend to form a single pore framework structure.
