Excellent Self-healing Capability Research Articles

Scalable polyolefin-based all-organic dielectrics with superior high-temperature capacitive energy storage performance

Polymer dielectrics capable of efficient and stable operation at elevated temperatures (>150 °C) are urgently needed to meet the stringent requirements of capacitive energy storage in harsh environments. However, the current leading commercially available polymer dielectric, biaxially oriented polypropylene (BOPP), can only sustain continuous operation at temperatures below 85 °C due to its limited thermal stability and significant increase in electrical conduction at high temperatures. Here, we present an all-organic polymer composite comprising nonpolar polyolefin and organic semiconductor that demonstrates superior dielectric and capacitive energy storage performance at 150 °C. Notably, the dielectric properties of the polymer composite remain stable across a broad temperature range, exhibiting an ultralow dissipation factor at elevated temperatures. Benefiting from the deep trap energy levels introduced by the organic semiconductor, the composite film achieves one order of magnitude reduction in electrical conductivity. As a result, the composite film attains discharged energy densities of 7.1 J/cm3 and 5.5 J/cm3 with a charge-discharge efficiency of 90 % at 25 °C and 150 °C, respectively. Furthermore, the composite film maintains stable capacitive performance over extended charge-discharge cycles (50,000 cycles) in harsh environments (500 MV/m and 150 °C), along with excellent breakdown self-healing capability. These remarkable performances, coupled with the potential for large-scale production using commercially available raw materials, highlight the practically viability of the composite film for high-temperature capacitive energy storage applications.

Injectable antibacterial hydrogels based on oligolysines for wound healing

Generally, oligolysine has poor antibacterial effect and almost no antibacterial activity. Herein, low cost and easily available oligolysines were chosen to prepare injectable antibacterial hydrogel (PVAL-gel) for wound healing. The hydrogel network was formed by cross-linking vanillin acrylate-N, N-dimethylacrylamide copolymer P(VA-co-DMA), oligolysine and adipate dihydrazide through Schiff base bond. The obtained hydrogel PVAL-gel exhibited not only excellent self-healing capability and injectability, but also the efficient contact antibacterial ability and good inhibitory effects on E.coli and S.aureus. In vitro, 99.9 % of pathogenic bacteria was killed within 160 min. Furthermore, the injectable PVAL-gel could rapidly eradicate bacteria in infected wounds and notably enhance the healing of full-thickness skin wounds. Therefore, PVAL-gel is expected to be used as a high-end dressing for the treatment of infected skin wounds, which can promote wound healing.

Polypropylene nanocomposite film with enhanced energy storage performance via a continuous preparation

Dielectric polymers have been extensively employed in renewable energy conversion, hybrid electric vehicle, and high voltage direct current transmission systems, owing to their excellent electrical insulation, processability, and self-healing capability. However, the challenge lies in their relatively low dielectric constant (εr) and limited discharge energy density (Ue), which hinder the advancement of integrated power modules. Despite numerous efforts aimed at enhancing Ue, the fabrication of scalable dielectric film with both enhanced Ue and high charge–discharge efficiency (η) remains a major obstacle. Herein, the polypropylene-based films with BaTiO3@PP-g-MAH (BTO@PP-g-MAH) core–shell nanoparticles are prepared through a continuous melt extrusion process. The resulting nanocomposite film, incorporated with 5 wt% BTO@PP-g-MAH, exhibits an impressive Ue of 5.15 J cm−3 and achieves a high η of 93.2 % at 433 MV m−1, along with excellent cycle dielectric stability. Such enhancements in εr and Ue are ascribed to the improved interfacial polarization facilitated by BaTiO3 nanoparticles and the enhanced interface binding achieved through the PP-g-MAH shell layers. Furthermore, the enhancement of electric breakdown strength (Eb) is comprehensively investigated based on electrical breakdown mechanism and electromechanical breakdown model. This study demonstrates a novel strategy to prepare nanocomposite dielectric films that are compatible with commercial capacitor fabrication process.

Structure-property relationship of polyhedral oligomeric silsesquioxanes/polydimethylsiloxane superhydrophobic coatings for cotton fabrics

Cotton fabrics are extensively utilized in daily life due to striking advantages such as softness, breathability, skin-friendliness, and cheapness. However, they are susceptible to being contaminated owing to inherent amphiphilicity, severely affecting service lifespan and aesthetic perception. To address this issue, three distinct types of the POSS/PDMS composite coatings are explored, and applied to cotton fabrics, respectively. Subsequently, the correlations between structures of POSS and properties of the composite coatings on the modified cotton fabrics are discussed. The results show that the three types of the POSS/PDMS composite coatings impart the modified fabrics with robust superhydrophobicity even in harsh environments including mechanical damage, chemical corrosion and UV-irradiation. Notably, the damaged POSS/PDMS composite coatings on cotton fabrics can exhibit excellent superhydrophobic self-healing capability by simple heating. Meanwhile, the modified fabrics also show excellent performances in self-cleaning, anti-fouling, anti-icing and oil-water separation applications. Additionally, due to multifunctional groups of MTPOSS, the cotton fabric treated by the MTPOSS/PDMS composite coating exhibits more excellent thermal, mechanical, and UV protection properties without significantly compromising its air permeability as compared to those of the other coated cotton fabrics. This work will pave the way to exploitation and applications of novel multifunctional textiles.

PEDOT:PSS based reprocessingly multifunctional dispersions and their optoelectronic films with excellent self-healing capability

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) has become a hot and excellent candidate material for organic electronics. However, its film applications are limited due to its high accidental scratching or damage brittleness, easy moisture absorption and poor mechanical properties, etc. Herein, a thermo-driven healable waterborne polyurethane (WPU-DA) was introduced into PEDOT:PSS aqueous dispersion by simple mechanical mixing. The film prepared by the uniform mixture with cracks less than 10 μm achieved multiple structural morphology healing under treating at 130 °C for 10 min and then 65 °C for 1 h, and this process had little effect on its original electrical properties. Moreover, the film has good resistance to various solvents, especially water even after 14 days of immersion. The film also has excellent flexibility and electrochromic capability which can maintain stable electrical path even after multiple bending-stretching operations. In addition, the film can realize the synergistic healing of structural morphology and electrochromic properties, and a freeze-drying and redispersion process can reproduce above characteristics, supporting the long-term storage and in-site fabrication of polymer dispersions.

Bicontinuous Ionogel Electrolyte with Conductive Nanochannels for Flexible Supercapacitors.

Ionogels with excellent mechanical performance and conductivity have been considered as ideal candidates for flexible ionotronics. However, current ionogels suffer from the well-known trade-off between mechanical strength and conductivity. Herein, we construct an ionogel with bicontinuous phase structures, a polymer-rich phase, and a solvent-rich phase. The synergy of the polymer-rich phase as an energy dissipation mechanism and the solvent-rich phase as a conductive nanochannel enables the resultant bicontinuous ionogel to show comprehensive properties, a tensile strength of 4.2 MPa, a toughness of 14.4 MJ/m3, a conductivity of 4.3 mS/cm, excellent self-healing capability, and reprocessability. Benefiting from the remarkable mechanical performance and high conductivity, the integrated supercapacitor achieves a high specific capacitance of 118 mF/cm2 (at a current density of 0.2 mA/cm2) and a capacitance retention of up to 90% (1000 charge-discharge cycles). More significantly, the resultant supercapacitor retains outstanding electrochemical performance even after being subjected to various deformations and even under harsh conditions. This study provides a reliable strategy for developing a high-performance ionogel electrolyte and broadens its application in flexible ionotronics.

Dynamic carboxymethyl chitosan prodrug hydrogel precisely mediates robust therapy on wound infection

Dynamic antibacterial polysaccharide prodrug hydrogels are in great demand for treatment of wound infection owing to their unique advantages such as excellent biocompatibility, superior antimicrobial property as well as favorable wound healing capacity. Herein, this work highlights the successful development of a dynamic carboxymethyl chitosan (CMC) prodrug hydrogel, which is facilely constructed through Schiffer base reaction between antibacterial components (amikacin and CMC) and crosslinker (dialdehyde PEG). Moderate dynamic imine linkages endow the hydrogel with excellent injectable and self-healing capability as well as targeted on-demand drug release in slightly alkaline condition at infected wound. All ingredients and their strong intermolecular interactions endow the hydrogel with favorable swelling and moisture retention capability. Moreover, the covalent and non-covalent interactions also endow the hydrogel with superior adhesion and mechanical property. These attractive characteristics enable hydrogel to effectively kill pathogens, promote wound healing and reduce side effects of amikacin. Thereby, such a dynamic CMC prodrug hydrogel may open a new avenue for a robust therapy on wound infection, greatly advancing their use in clinics.

Superhydrophobic and self-healing silane-ceria composite coating implanted with 1,5-naphthalenediol inhibitor for corrosion protection of AA2024-T3 aluminum alloy

A superhydrophobic silane coating was modified by incorporating hollow CeO2 nanocontainers loaded with 1,5-naphthalenediol (ND) and used for the corrosion protection of an AA2024-T3 aluminum alloy. The CeO2 nanocontainers exhibited a high loading capacity of 22.1 % for the ND inhibitor. After 8 h immersion, 93 % of the ND inhibitor was desorbed from CeO2@ND nanoparticles in a 3.5 wt% NaCl solution. Electrochemical impedance spectroscopy results indicated that the incorporation of CeO2@ND particles significantly enhanced the polarization resistance and the protection efficiency of the fabricated silane-CeO2@ND hybrid coating was 98.3 %. Additionally, the protection efficiency of the coating slightly decreased to 98.2 % after 25 days of corrosion. Moreover, the scratch test indicated an excellent self-healing capability of silane-CeO2@ND nanocomposite. The outstanding self-repairing property of the coating was depended on the synergistic effects of inhibitive CeO2 nanocontainers and the loaded ND inhibitor.

Novel low-shrinkage dental resin containing microcapsules with antibacterial and self-healing properties

Dental resin restorations commonly fail because of fractures and secondary caries. The aim of this research was to synthesize a novel low-shrinkage dental resin with antibacterial and self-healing properties. The low-shrinkage dental resin was obtained by incorporating a 20 wt% anti-shrinkage mixture of an expanding monomer 3,9-diethyl-3,9-dimethylol −1,5,7,11-tetraoxaspiro[5,5] undecane and an epoxy resin monomer diallyl bisphenol A diglycidyl ether (1:1, referred as “UE”) and different mass fractions of self-healing antibacterial microcapsules (0%, 2.5%, 5%, 7.5%, and 10%) were incorporated into the matrix to prepare multifunctional dental resin. Polymerization shrinkage, mechanical properties, antibacterial activity, self-healing ability, and cytotoxicity of this dental resin were evaluated. The polymerization volumetric shrinkage of resin containing 20 wt% UE and 7.5 wt% microcapsules was reduced by 30.12% (4.13% ± 0.42%) compared with control. Furthermore, it exhibited high antibacterial activity and a good self-healing efficiency of 71% without adversely affecting the mechanical property and cell viability. This novel multifunctional dental resin with low polymerization shrinkage and excellent antibacterial activity and self-healing capability has potential application as a dental resin material to decrease the incidence of fractures and secondary caries.

Dynamic Cross-Linked Polyethylene Networks with High Energy Storage and Electrical Damage Self-Healability.

Dielectric polymers that exhibit high energy density Ue, low dielectric loss, and thermal resistance are ideal materials for next-generation electrical equipment. The most widely utilized approach to improving Ue involves augmenting the polarization through increasing the dielectric constant εr or the breakdown strength Eb. However, as a conflicting parameter, the dielectric loss also increases inevitably at the same time. In addition, due to the long-term work under a strong electric field or high potential, dielectric materials often produce electrical damage (electrical tree), which is one of the main factors affecting the reliability and service life of electrical equipment. To address these problems, we herein develop dynamic cross-linked polyethylene materials (PE-MA-Epo) by polyethylene-graft-maleic anhydride (PE-MA) and polar epoxy monomers, which showed high εr (>7), low dielectric loss (<0.02), high Ue (5.16 J/cm3 at 425 MV/m), and outstanding discharge efficiency (97%). The performances of the materials are adequate to rival biaxially oriented polypropylene (BOPP) films. Moreover, the excellent self-healing capability of PE-MA-Epo enables the total recovery of εr and tan δ after electrical tree healing. After two cycles of electrical breakdown healing, Eb remained at 80%, which improves the durability and reliability of dielectric polymers. Therefore, PE-MA-Epo shows great potential for applications in advanced electronic power devices.

A flexible, autonomous self-healing and high ionic conductivity hydrogel electrolyte for all-in-one supercapacitor

Conventional polyvinyl alcohol-based gel electrolytes are generally limited in ionic conductivity and cannot well meet the requirements of the self-healing and flexible smart device. Herein, we design a highly conductive hydrogel electrolyte (ionic conductivity up to 84 mS cm−1), based on cross-linked aqueous acrylamide (AAm) solution in the presence of poly(N-vinylpyrrolidone) (PVP), with excellent self-healing capability by intermolecular hydrogen bonds between PVP and PAM. The self-healing all-in-one flexible supercapacitor fabrication with the gel electrolyte and in-situ polymerization polypyrrole (PPy) electrode can achieve repeated healable 5 cycles without extra addition, stretch up to 750 % compared with the original lengths and bend different angles with slight performance decay. This work provides new idea for the synthesis of highly conductive, self-healing and flexible hydrogel electrolyte to promote the development of all-in-one supercapacitor with high specific capacitance for practical applications in flexible and wearable electronics.

Self-healing and freezing-tolerant strain sensor based on a multipurpose organohydrogel with information recording and erasing function

Smart hydrogels with various stimuli-responsiveness have shown tremendous prospects in the areas of electronic skins, artificial medical organization and soft robotics. Herein, a multifunctional organohydrgel is prepared by introducing polyvinylpyrrolidone (PVP), acrylic acid (AA) and acrylamide (AAm) into water/dimethyl sulfoxide (H2O/DMSO) binary solvent system. The introduced PVP and chemical cross-linked P(AA-co-AAm) chains based double network structures and the amount of reversible hydrogen bonds between polymer chains endow the as-prepared organohydrogel with excellent mechanical property (1554 % strain) and self-healing capability. Meanwhile, the organohydrogel exhibits extraordinary low-temperature tolerance (−40 ℃) and long-term anti-drying property (83 % moisture retention after 7 days) due to the strong interactions between water and DMSO. Furthermore, the flexible strain sensor based on the organohydrogel displays a wide strain sensing range (0–500 %) and repeatable response capability, which can precisely monitor varying degrees of stretching deformations and a series of intricate human movements. Owing to the remarkable freezing resistance and self-healing property, the original and healed organohydrogel sensors still exhibit stable sensing behaviors in freezing environment of −40 ℃. Noticeably, the obtained organohydrogel can also be served as a special paper to realize the information recording and erasing function at subzero temperatures. These outstanding performances indicate the organohydrogels may be employed as durable and freezing-tolerant smart materials applied in future flexible electronics, soft robots and information platform.

Application of poly (dimethyl diallyl ammonium chloride)−reinforced multifunctional poly (vinyl alcohol)/ polyaniline hydrogels as flexible sensor materials

The design of multifunctional hydrogel sensor materials with comprehensive properties such as frost resistance, good reusability, adhesion, and flexibility needs to be developed to meet the demands of complex environments. Herein, a conductive, semi-interpenetrating network hydrogel was constructed from poly (vinyl alcohol), polyaniline (PANI), and poly (dimethyl diallyl ammonium chloride) (PDDA), and the process assisted by the Hofmeister effect. A double conductive pathway hydrogel with types of PDDA and PANI polymers was formed simultaneously to provide excellent conductivity (1.217 S/m−1) for the hydrogel. With the increase in the concentration of PDDA from 0 to 16 wt%, the mechanical strength increased from 0.066 MPa to 0.34 MPa, and the modulus of elasticity and toughness increased by 684.9% and 748.8%, respectively. The hydrogel can be efficiently generated as a strain sensor material with excellent sensitivities of GF= 2.337 and S= 3.229%/KPa under tension and compression, respectively. The hydrogel could be used as an electronic skin and be used for the monitoring of even small strains in the skin caused by pulse beats. In addition, the hydrogel has excellent temperature sensitivity (1.575%/℃), frost resistance (−53.45 ℃), self-healing capability, and reusability. Data AvailabilityData will be made available on request.

Fluorescent double network ionogels with fast self-healability and high resilience for reliable human motion detection.

Fascinating properties are displayed by high-performance ionogel-based flexible strain sensors, thereby gaining increasing attention in various applications ranging from human motion monitoring to soft robotics. However, the integration of excellent properties such as optical and mechanical properties and satisfactory sensing performance for one ionogel sensor is still a challenge. In particular, fatigue-resistant and self-healing properties are essential to continuous sensing. Herein, we design a flexible ion-conductive sensor based on a multifunctional ionogel with a double network using polyacrylamide, amino-modified agarose, 1,3,5-benzenetricarboxaldehyde and 1-ethyl-3-methylimidazolium chloride. The ionogel exhibits comprehensive properties including high transparency (>95%), nonflammability, strong adhesion and good temperature tolerance (about -96 to 260 °C), especially adaptive for extreme conditions. The dynamic imine bonds and abundant hydrogen bonds endow the ionogel with excellent self-healing capability, to realize rapid self-repair within minutes, as well as good mechanical properties and ductility to dissipate input energy and realize high resilience. Notably, unexpected fluorescence has been observed for the ionogel because of the gelation-induced emission phenomenon. Flexible strain sensors prepared directly from ionogels can sensitively monitor and differentiate various human motions, exhibiting a fast response time (38 ms), high sensitivity (gauge factor = 3.13 at 800% strain), good durability (>1000 cycles) and excellent stability over a wide temperature range (-30 to 80 °C). Therefore, the prepared ionogel as a high-performance flexible strain sensor in this study shows tremendous potential in wearable devices and soft ionotronics.

Biomimetic supramolecular polyurethane with sliding polyrotaxane and disulfide bonds for strain sensors with wide sensing range and self-healing capability.

To prolong the service life of flexible electronic materials, polymeric matrixes with excellent self-healing capability and integrated mechanical properties are highly desirable, but the balance between the self-healing capability and mechanical properties is a grand challenge. Here, polyrotaxanes as sliding crosslinkers and dynamic disulfide bonds are incorporated into the main chains of polyurethane (PU) via one-pot synthesis, which endows the PU with polydisperse hard/soft segments, high density of self-healing points and energy dissipation. Based on this judicious molecular design, the PU elastomers exhibit exceptional mechanical properties, such as high stretchability (1167% with a tensile strength of 3.49MPa), high fracture energy (20,775Jm-2) and high puncture energy (200.70mJ). Moreover, due to the presence of dynamic reversible hydrogen and disulfide bonds, the elastomer could achieve stress and strain repair efficiencies of 93.98% and 99.21% at 100 ℃ within 1h, respectively. The above-mentioned superiorities enable the bioinspired strain sensors to possess a large sensing range (∼596%), high sensitivity (∼79.98), short response time (∼128ms), along with excellent reliability and self-healing ability. Besides, the strain sensor exhibits remarkable recyclability and prominent reprocessability, which nicely solves the pollution by discarded electronics.

Incorporating self-healing capability in temperature-sensitive hydrogels by non-covalent chitosan crosslinkers

Through the use of non-covalent chitosan (CS) crosslinkers, reversible yet strong non-covalent interactions are introduced into the poly-N-isopropylacrylamide (PNIPAM) temperature-sensitive hydrogel, which renders desirable mechanical properties, biocompatibility, and most importantly high-level self-healing capability, in combination of facile temperature response near body temperature for drug loading/release. Best overall performance is then reached by optimizing the formulation of CS, N-isopropylacrylamide (NIPAM), acrylic acid (PAA), and acrylamide (AM) in the CS-g-P(NIPAM-AM-AA) graft copolymer system. By virtue of quantum chemical calculations, the nature of a variety of non-covalent interactions within the hydrogel framework is uncovered, those of which between CS and PAM units is found to be superiorly strong, being predominately responsible for the excellent self-healing capability. Synthesis of the hydrogel system simply requires a single-step one-pot procedure, where low cost of all components and the production process is guaranteed. After a series of synthetic optimizations, we notice that hydrogel with NIPAM/AM = 7/1 have the lower critical solution temperature (LCST, 37 °C) corresponding to human body temperature, elongation at break of more than 1500%, strain recovery ratio and stress recovery ratio of 92.89% and 96.15%, remarkable biocompatibility and can provide a good and stable drug loading and release platform. In a nutshell, this study provides a low-cost yet highly viable approach for self-healable thermosensitive hydrogels with biocompatibility, which is appropriate for commercial uses.

Dual-crosslinked hyaluronic acid hydrogel with self-healing capacity and enhanced mechanical properties

Self-healing hydrogels can repair their cracks, and restore their original properties. However, self-healing hydrogels usually face low mechanical strength and poor stability. By the dual crosslinking strategy, a self-healing hyaluronic acid-based hydrogel with enhanced strength was fabricated by dynamic acylhydrazone linkages between aldehyde-modified maleic sodium hyaluronate and 3,3′-dithiobis (propionylhydrazide) and subsequent photopolymerization among maleic groups in the hydrogel network. The hydrogels exhibit fast gelation and excellent self-healing capability due to the dynamic and reversible characteristics of acylhydrazone and disulfide linkages. Furthermore, the dual crosslinking increase the mechanical strength of the hydrogels and prolong their stabilization time. Swelling behaviors, morphology, and mechanical properties could be adjusted by altering the molar ratio of –NH–NH2/–CHO. Besides, the hydrogels displayed interesting pH-responsiveness and cytocompatibility. The hydrogels have potential applications in cell culture, drug delivery, and 3D bioprinting.

Design of inherent fire retarding and degradable bio-based epoxy vitrimer with excellent self-healing and mechanical reprocessability

Epoxy resins possess poor flame retardancy and have difficulty in both recycling and reprocess ability which largely limit their application. Herein, two vanillin-based epoxy monomers, shorted as VAD-EP and VDP-EP, containing both imine bonds and inherently fire retarding phosphorus elements, were synthesized via in situ condensation reaction with DDM and addition reaction with DOPO, followed by the epoxidation by epichlorohydrin. Epoxy vitrimer materials were then cured by D230 diamine hardener by adjusting the proportion of VAD-EP and VDP-EP monomer. When the mass ratio of VAD-EP and VDP-EP was 8:2, A8P2-D230 reached the fire retarding UL-94 V0 rating and LOI value of 27.0% with only 0.66% of phosphorus content, this behavior was ascribed to condensed phase and free radical scavenging mechanisms. When the mass ratio was 7:3, the tensile strength and elastic modulus of the A7P3-D230 epoxy were 75.5 MPa and 2.5 GPa, respectively, i.e. 48.6% and 18.8% higher than A10P0-D230 sample. Meanwhile, the material showed high stress relaxation rate, due to the presence of dynamic imine bonds in the topological crosslinking network. As a consequence, the epoxy vitrimer exhibited excellent self-healing capability, reprocessability and degradation behaviors. The biobased epoxy vitrimer was then used to prepare the carbon fibers (CFs) reinforced epoxy composites, results showed that CFs can be completely recycled. Interestingly, the recycled CFs maintain unchanged chemical structure, mechanical properties and morphology as the original CFs.

Strengthened self-healable natural rubber composites based on carboxylated cellulose nanofibers participated in ionic supramolecular network

Cellulose, as a green reinforcing agent for rubber, has excellent improvement on the tensile strength but usually accompany with a deterioration of extensibility and self-healing property. Herein, we report an efficient method to prepare robust and self-healable natural rubber/zinc dimethacrylate/carboxylated cellulose nanofibers (NR/ZDMA/CNC) composites which are constructed by a CNC participated ionic supramolecular network. Ionic supramolecular network in NR is generated by the polymerization of ZDMA during a controlled peroxide-initiated vulcanization of NR. Interestingly, NR with massive ion clusters has strong affinity with CNC, which facilitates the uniform dispersion of CNC and the compatibility between CNC and NR. Meanwhile, CNC participates into the supramolecular network via non-covalent interaction with NR chains equipped with ionic crosslinks. This greatly reduces the adverse effect of CNC on the dynamic characteristics of supramolecular network. As a result, the tensile strength of NR/ZDMA composite with 20 phr CNC could reach 4.13 MPa, while its self-healing efficiency still maintains at >80 %. Thus, NR composites with non-covalent interaction between CNC and supramolecular network display improved strength, maintained extensibility, and excellent self-healing capability. This study thus demonstrates a feasible approach to reduce the negative effect of reinforcing fillers on a self-healing rubber based on supramolecular networks.

Brain Microenvironment Responsive and Pro-Angiogenic Extracellular Vesicle-Hydrogel for Promoting Neurobehavioral Recovery in Type 2 Diabetic Mice After Stroke.

Stroke patients with diabetes have worse neurological outcomes than non-diabetic stroke patients, and treatments beneficial for non-diabetic stroke patients are not necessarily effective for diabetic stroke patients. While stem cell-derived extracellular vesicles (EVs) show potential for treating stroke, the results remain unsatisfactory due to the lack of approaches for retaining and controlling EVs released into the brain. Herein, a glucose/reactive oxygen species dual-responsive hydrogel showing excellent injectability, biocompatibility, and self-healing capability is introduced as an EVs-loading vehicle and an intelligent EVs sustained releasing system in the brain. These EVs-hydrogels are developed via crosslinking of phenylboronic acid-modified hyaluronic acid and Poly vinyl alcohol, and fusion with neural stem cell-derived EVs. The results show EVs are stably incorporated into the hydrogels and can be controllably released in response to the brain microenvironment after stroke in type 2 diabetic mice. The EVs-hydrogels exert an excellent angiogenic effect, increasing the migration and tube formation of human umbilical vein endothelial cells. In addition, injection of EVs-hydrogels into the ischemic mouse brain enhances EVs retention and facilitates sustained release, promotes angiogenesis, and improves neurobehavioral recovery. These results suggest such a microenvironment responsive and sustained release EVs-hydrogel system offers a safe, and efficient therapy for diabetic stroke.