Self-healing Efficiency Research Articles

Ultratough Supramolecular Polyurethane Featuring an Interwoven Network with Recyclability, Ideal Self-Healing and Editable Shape Memory Properties.

Developing multifunctional polymers with excellent mechanical properties, outstanding shape memory characteristics, and good self-healing properties is a formidable challenge. Inspired by the woven cross-linking strategy, a series of supramolecular polyurethane (PU) with an interwoven network structure composed of covalent and supramolecular cross-linking nodes have been successfully synthesized by introducing the ureido-pyrimidinone (UPy) motifs into the PU skeleton. The best-performing sample exhibited ultrahigh strength (∼77.2 MPa) and toughness (∼312.7 MJ m-3), along with an ideal self-healing efficiency (up to 90.8% for 6 h) and satisfactory temperature-responsive shape memory effect (shape recovery rates up to 96.9%). Furthermore, it ensured recyclability. These favorable properties are mainly ascribed to the effective dissipation of strain energy due to the disassembly and reconfiguration of supramolecular nodes (i.e., quadruple hydrogen bonds (H-bonds) between UPy units), as well as the covalent cross-linking nodes that maintain the integrity of the polymer network structure. Thus, our work provides a universal strategy that breaks through the traditional contradictions and paves the way for the commercialization of high-performance multifunctional PU elastomers.

Bio-based polyurethane triboelectric nanogenerator with superior low-temperature self-healing performance for unmanned surveillance

Damaged flexible triboelectric nanogenerators face difficulties in autonomous healing at low temperatures, limiting their application range. Impeded dynamic network reconstruction presents a challenge in developing materials for autonomous low-temperature healing. This study constructed a multi-dynamic network utilizing both strong and weak hydrogen and disulfide bonds to develop a biobased polyurethane elastomer (PBES-U, prepared from biobased monomers such as itaconic acid, sebacic acid, etc.), featuring a cross-linked network capable of cryogenic self-healing, superior toughness, and reprocessability. This elastomer extends to 1100 % of its original length, achieving 90 % self-healing efficiency at temperatures down to −10 °C due to the low glass transition temperature (Tg, −30 ℃) achieved by modulating the flexibility of chain segments. Consequently, a bio-based TENG (LS-TENG) was produced using this elastomer as a positive friction layer through a dynamic interfacial interlocking method. The results reveal that LS-TENG achieves a notable power density of 12.2 mW/m2, an output voltage reaching 160 V, and a 98 % output voltage recovery post-low-temperature self-healing. Furthermore, a non-contact LS-TENG-based monitoring system was developed with significant potential for applications in battlefield sensing, wildlife monitoring, and intelligent driving.

High-Strength and High-Toughness Supramolecular Materials for Self-Healing Triboelectric Nanogenerator.

The development of self-healing materials provides a new opportunity and challenge for advancing triboelectric nanogenerators (TENGs). However, the low strength and low toughness of self-healing triboelectric materials often result in the deformation or breakage of TENG under high mechanical loads, thereby limiting their potential applications. Herein, a new strategy for fabricating self-healing triboelectric materials is reported, which introduces cross-linking networks with hydrogen bonds and metal coordination bonds. The desired high performance can be achieved by simply adjusting the molar ratio of the metal to the ligand. When the molar ratio is 1:2, the tensile strength, toughness, and elongation atbreak of the material reached 13.7MPa, 76.9MJ m-3, and 1321%, respectively. Furthermore, its self-healing efficiency can reach 74% at 70°C in 6 h. Working in contact-separation mode, the electrical output can reach 164V, 18.2µA, 57.5 nC, with a maximum power density of 2.54W m-2. Notably, even if it is sheared, the electrical output performances of TENG can be completely recovered to the original state. In addition, the developed TENG exhibits excellent output stability over 10000 contact separation cycles. This study presents a promising approach for the development of stretchable smart generators.

MXene-based conductive hydrogels with toughness and self-healing enhancement by metal coordination for flexible electronic devices

MXene-based conductive hydrogels have emerged as a new type of soft materials in flexible electronics. Herein, metal coordination is introduced into MXene-based conductive hydrogels to synchronously enhance the mechanical and self-healing properties. MXene-based conductive hydrogels are made up of polyacrylic acid (PAA), sium carboxymethyl cellulose (SCMC), Ti3C2TX and metal ions (Ni2+, Al3+ or Sn4+). PAA/SCMC/Ti3C2TX/Sn4+ hydrogel is found to have excellent mechanical (stress: 122 kPa; strain: 1688 %; toughness: 0.95 ± 0.12 MJ m−3) and self-healing (self-healing efficiency: 99.27 % (conductivity); 81.16 % (stress); and 83.13 % (strain)) properties due to the metal coordination and H-bonding. The hydrogel has also good conductivity of 0.82 S m−1 and adhesion of 38.94 kPa. The flexible sensors based on this hydrogel can efficiently detect human motions, electromyography (EMG), electrocardiography (ECG) and handwriting signals. Furthermore, a supercapacitor assembled from this hydrogel has a high specific capacitance of 118.66 F g−1 and good stability (15000 charge-discharge cycles). This work provides an effective strategy for exploiting mechanically tough and self-healing MXene-based conductive hydrogels with prospective applications in flexible electronics.

Fabrication of organogel strain sensor with self-healing property and extreme temperature tolerance by using phytic acid-liquid metal as initiator

Wearable strain sensors have aroused myriad of interest in the domain of electronic skin, soft robotics, and biomedicine. Organogels for wearable strain sensors require desirable stretchability, sensing stability, self-healing property, and a wide working temperature range. However, the synthesis of such organogels typically involves complex and time-consuming processes. Herein, we proposed a rapid copolymerization method for organogels composed of poly(acrylic acid-co-acrylic amide) (P(AA-co-AM)), phytic acid (PA), liquid metal (LM), and polyethylene oxide (PEO). The dispersion of GaInSn in PA solution (GaInSn-PA) was synthesized and employed to initiate the copolymerization of acrylic acid (AA) and acrylic amide (AM), which significantly reduced polymerization time to 2–3 min at room temperature. The release of Ga3+ ions from the LM facilitated cross-linking of P(AA-co-AM) chains through coordination bonds, while also imparted conductivity to the organogel. The synergistic effect between hydrogen bonds and metal coordination bonds extensive within the polymer chains imparted exceptional stretchability (1079 % strain) and self-healing efficiency (98 % at 60 °C) to the organogel. Consequently, the resulting strain sensor demonstrated the ability to accurately monitor both subtle and large human motion, exhibiting remarkable repeatability and durability across a wide temperature range (-20 °C∼40 °C). In addition, the integration of strain sensors on limbs for robotic control through limb movements underscored its practical viability. This optimized fabrication approach and structural design strategy set a new precedent for the development of organogel strain sensors in various applications.

Internal catalysis significantly promotes the bond exchange of covalent adaptable polyurethane networks

Self-healing covalent adaptable networks (CANs) are not only of fundamental interest but also of practical importance for achieving carbon neutrality and sustainable development. However, there is a trade-off between the mobility and cross-linking structure of CANs, making it challenging to develop CANs with excellent mechanical properties and high self-healing efficiency. Here, we report the utilization of a highly dynamic four-arm cross-linking unit with an internally catalyzed oxime-urethane group to obtain CAN-based ionogel with both high self-healing efficiency (>92.1%) at room temperature and superior mechanical properties (tensile strength 4.55 MPa and toughness 13.49 MJ m-3). This work demonstrates the significant potential of utilizing the synergistic electronic, spatial, and topological effects as a design strategy for developing high-performance materials.

Photocurable vitrimers with malleable and self-healing trade-off enabled by manipulating dynamic boronic ester bonds

Although numerous strategies refer to dynamic covalent bond exchanges of small molecules for self-repairing thermosets, it remains a critical challenge to be able to jointly tune the malleability and dynamic properties of photocurable materials via extending dynamical small molecule bridging chains with tunable kinetic features. Herein, we successfully synthesized two typical diboronic ester molecules (diboronic ester dithiol/diacid) with variable dioxaborolane metathesis kinetics, which acted as dynamical interlinking segments constructing simple hydrogenated bisphenol A (HBA) epoxy backbone to achieve dynamically cross-linking feature. Subsequently, the acrylate- and anhydride-modified HBA vitrimers bearing diboronic ester-extending segment variants and photocuring traits are successfully synthesized by a one-pot reaction. Consequently, it is demonstrated that the embedded amounts of dynamic diboronic ester bonds in the backbone play a key role in the photopolymerization rate of photocurable vitrimers. The photopolymerization rate decreases significantly as more diboronic ester segments. Moreover, the diboronic ester dithiol-mediated photocurable vitrimer (HBA-S) exhibits enhanced malleability (strain at break of 26.6 %), desirable photo-crosslinked network, and accelerated thermal-triggered self-healing ability (scratch self-healing efficiency of closing to 100 % at 150 °C), compared to those of the diboronic ester diacid-mediated vitrimer (HBA-O) under identical conditions. This work validates the probability of transferring the dioxaborolane metathesis of small molecules to dynamic properties of bulk UV-curing materials, which provides valuable guidance for the rational design and fabrication of tunable dynamic photocurable materials.

Bio-Based Polyurethane-Urea with Self-Healing and Closed-Loop Recyclability Synthesized from Renewable Carbon Dioxide and Vanillin.

Developing recyclable and self-healing non-isocyanate polyurethane (NIPU) from renewable resources to replace traditional petroleum-based polyurethane (PU) is crucial for advancing green chemistry and sustainable development. Herein, a series of innovative cross-linked Poly(hydroxyurethane-urea)s (PHUUs) were prepared using renewable carbon dioxide (CO2) and vanillin, which displayed excellent thermal stability properties and solvent resistance. These PHUUs were constructed through the introduction of reversible hydrogen and imine bonds into cross-linked polymer networks, resulting in the cross-linked PHUUs exhibiting thermoplastic-like reprocessability, self healing, and closed-loop recyclability. Notably, the results indicated that the VL-TTD*-50 with remarkable hot-pressed remolding efficiency (nearly 98.0%) and self-healing efficiency (exceeding 95.0%) of tensile strength at 60 °C. Furthermore, they can be degraded in the 1M HCl and THF (v:v = 2:8) solution at room temperature, followed by regeneration without altering their original chemical structure and mechanical properties. This study presents a novel strategy for preparing cross-linked PHUUs with self-healing and closed-loop recyclability from renewable resources as sustainable alternatives for traditional petroleum-based PUs.

Ultrarobust, Self-Healing Poly(urethane-urea) Elastomer with Superior Tensile Strength and Intrinsic Flame Retardancy Enabled by Coordination Cross-Linking.

Poly(urethane-urea) elastomers (PUUEs) have gained significant attention recently due to their growing demand in electronic skin, wearable electronic devices, and aerospace applications. The practical implementation of these elastomers necessitates many exceptional properties to ensure robust and safe utilization. However, achieving an optimal balance between high mechanical strength, good self-healing at moderate temperatures, and efficient flame retardancy for poly(urethane-urea) elastomers remains a formidable challenge. In this study, we incorporated metal coordination bonds and flame-retarding phosphinate groups into the design of poly(urethane-urea) simultaneously, resulting in a high-strength, self-healing, and flame-retardant elastomer, termed PNPU-2%Zn. Additional supramolecular cross-links and plasticizing effects of phosphinate-endowed PUUEs with relatively remarkable tensile strength (20.9 MPa), high elastic modulus (10.8 MPa), and exceptional self-healing efficiency (above 97%). Besides, PNPU-2%Zn possessed self-extinguishing characteristics with a limiting oxygen index (LOI) of 26.5%. Such an elastomer with superior properties can resist both mechanical fracture and fire hazards, providing insights into the development of robust and high-performance components for applications in wearable electronic devices.

Biomimetic three-dimensional microchannel non-destructive self-healing flexible strain sensor based on liquid metal-polydimethylsiloxane elastomer

Flexible strain sensors (FSS) have garnered widespread attention due to their immense potential in wearable electronics, motion health monitoring, artificial electronic skin, and soft robotics. However, FSSs are susceptible to mechanical damage such as wear, cracks or breaks during long-term use, which diminish their reliability and service life. Inspired by the self-healing dual-phase structure of human skin and vascular networks, this study proposes a biomimetic three-dimensional microchannel non-destructive self-healing flexible strain sensor (B-TMN-SHFSS) based on the liquid metal-polydimethylsiloxane (LM-PDMS) elastomer. The B-TMN-SHFSS employs a layered design, layer-by-layer fabrication, and interlayer self-healing techniques to construct the microchannel within the self-healing PDMS elastomer (SPE), with the liquid metal (LM) being injected into the microchannel using a negative pressure injection method. Based on the modified protective layer design of the biomimetic three-dimensional microchannel, the high self-healing efficiency of the SPE and the fluidity of the LM, the B-TMN-SHFSS is able to restore the initial sensing performance after self-healing, while maintaining the integrity of the 3D microchannels with an electrical healing efficiency (EHE) of 100 %. Additionally, the B-TMN-SHFSS features high sensitivity (GFmax = 3.464) and a wide measurement range (0 to 216.68 %), making it suitable for human motion detection.

A Review of Biomineralization as Solution for Roads and Infrastructures Concrete Sustainability

Concrete cracks in roads and infrastructure are ubiquitous due to environmental factors, fatigue, and material degradation. Applying bacteria with self-healing capabilities in concrete matrices is proposed as a solution. These bacteria, activated by water and oxygen ingress, produce calcium carbonate through biomineralization. They are improving structural integrity while reducing the adverse effects of chemical and water infiltration. The quantity of Bacillus bacteria to be added to the concrete mixture is an integral part of the standardization of the self-healing mechanism. 105 - 108 cells/mL of spores experienced improvement in mechanical properties and self-healing efficiency. Various Bacillus strains, such as Bacillus sphaericus, Bacillus subtilis, and Bacillus megaterium, are typically utilized in self-healing. The by-product of biomineralization, calcium carbonate, is an autonomous crack and pore sealer, which can be evaluated via SEM, XRD, and XDS. The study highlights the testing methodologies used to examine calcite deposition. Also, it reiterates the importance of urease activity evaluation before bacterial propagation to confirm the occurrence of the biomineralization process. Moreover, the article reiterates the bacteria's history, origin, and pathogenicity, bridging the gap concerning bacteria propagation safety and the need for industry-accepted standards and certification procedures. The transition from laboratory experiments to large-scale implementation is advocated to demonstrate bacterial concrete's sustainability and economic feasibility for broader industry adoption. Finally, bacteria concrete is a ground-breaking approach that unites construction and biology for long-term sustainable transportation materials and construction. Doi: 10.28991/CEJ-2024-010-08-020 Full Text: PDF

Mechanism of healing, strength, and durability concepts of bacteria concrete - a review

Abstract Research work is going on to explore the concept of self-healing concrete. Outcome of the investigation reveals potential of bacteria concrete. Self-healing capacity imparted to the concrete by incorporating bacteria. Traditional methods reported in the literature such as epoxy injection, grouting, drilling, and plugging and gravity filling method have environmental impact, require more maintenance and are time consuming. The self-healing mechanism can be a better alternative to compensate these defects due to ecofriendly nature. Self-healing mechanism involves the production of CaCO3 precipitate deposites in crack region. Review paper focused on self-healing efficiency, water permeability, chloride penetration, compressive strength, flexural strength and recovery of water tightness, percentage weight loss of both conventional and bacterial concrete. For good environment tomorrow and better sustainability, self-healing conceptin concrete structure contributes promising technology.

Bio-based polyurethane vitrimer with imine bonds: Excellent thermo-mechanical properties and heat recovery

Preparation of vitrimer with excellent performance from biomass feedstock can effectively reduce the waste of fossil fuels and the pollution problem to the environment. In this paper, vanillin (VAN) and 4-amino-3-methylphenol, which are biobased raw materials, were used to prepare the imine-bonded diol AMV-OH in a one-step process, which was incorporated into the main chain of vitrimer polymer, and a series of imine-bonded vitrimer materials AMV-V was obtained by using pentaerythritol tetra-3-mercaptopropionate (PETMP) as a cross-linking agent. The mechanical property analysis, solvent resistance analysis, DSC thermal analysis, DMA analysis and self-repair characterization showed that AMV-V exhibited good thermo-mechanical properties (the highest initial degradation temperature was 246 °C with a Tg value of 17 °C). The results showed that specific mechanical properties could be obtained by adjusting the contents of PETMP and AMV-OH, among which the best tensile properties were obtained at 10 mmol of AMV-OH, with a tensile strength of 8.03 MPa and an elongation at break of 316.79 %. Meanwhile, the AMV-V samples were able to achieve self-healing properties under milder conditions (100 °C, 10 MPa repair for 1 h) and had a high self-healing efficiency (H=94.80 %, R=83.72 %).

Proton Hydrogel-Based Supercapacitors with Rapid Low-Temperature Self-Healing Properties.

Hydrogel-based supercapacitors are an up-and-coming candidate for safe and portable energy storage. However, it is challenging for hydrogel electrolytes to achieve high conductivity and rapid self-healing at subzero temperatures because the movements of polymer chains and the reconstruction capability of broken dynamic bonds are limited. Herein, a highly conductive proton polyacrylamide-phytic acid (PAAm-PA) hydrogel electrolyte with rapid and autonomous self-healing ability and excellent adhesion over a wide temperature range is developed. PA, as a proton donor center, endows the hydrogels with high conductivity (102.0 mS cm-1) based on the Grotthuss mechanism. PA can also prevent the crystallization of water and form multiple reversible hydrogen bonds in the polymer network, which solves the dysfunction of self-healing hydrogels in a cryogenic environment. Accordingly, the hydrogel electrolytes demonstrate fast low-temperature self-healing ability with a self-healing efficiency of 79.4% within 3 h at -20 °C. In addition, the hydrogel electrolytes present outstanding adhesiveness on electrodes due to the generation of hydrogen bonds between PA and activated carbon electrodes. As a result, the integrated hydrogel-based supercapacitors with tight bonding electrode/electrolyte interface deliver a 139.5 mF cm-2 specific capacitance at 25 °C. Moreover, the supercapacitors display superb self-healing ability, achieving 92.1% of capacitance recovery after three cutting-healing cycles at -20 °C. Furthermore, the supercapacitors demonstrate only 6.4% capacitance degradation after 5000 charging-discharging cycles at -20 °C. This work provides a roadmap for designing all-in-one flexible energy storage devices with excellent self-healing ability over a wide temperature range.

Iridium(III)-Incorporating Self-Healing Polysiloxanes as Materials for Light-Emitting Oxygen Sensors.

Polymer-metal complexes (PMCs) based on poly(2,2'-bipyridine-4,4'-dicarboxamide-co-polydimethylsiloxanes) with cyclometalated di(2-phenylpyridinato-C2,N')iridium(III) fragments and cross-linked by Zn2+ (Zn[Ir]-BipyPDMSs) or Ir3+ (Ir[Ir]-BipyPDMSs) represent flexible, stretchable, phosphorescent, and self-healing molecular oxygen sensors. PMCs provide strong phosphorescence at λem = 595-605nm. Zn[Ir]-BipyPDMS with PDMS chain length of Mn = 5000 has the highest quantum yield of 9.3% and is a molecular oxygen sensor at different O2 concentrations (0-100vol%) compared to Ir[Ir]-BipyPDMSs. A Stern-Volmer constant is determined for Zn[Ir]-BipyPDMS as KSV = 0.014%-1, which is similar to the reported oxygen-sensitive iridium(III) complexes. All synthesized PMCs exhibit high elongation at break (up to 1100%) and self-healing efficiency (up to 99%).

A 3D self-floating solar vapor generator based on a novel self-healing aero-hydrogel containing peach gum polysaccharide with durability and continuous operation

Solar energy interfacial evaporation represents a promising and sustainable approach with considerable potential for seawater desalination and wastewater treatment. Nonetheless, creating durable evaporators for continuous operation presents a challenge. Motivated by natural self-healing mechanisms, this study developed a novel 3D hybrid aero-hydrogel, which exhibited a self-healing efficiency of 89.4 % and an elongation at break post-healing of 637.7 %, featuring self-healing capabilities and continuous operation potential. Especially, the incorporation of hyperbranched water-soluble polymers (peach gum polysaccharide) endow the final solar water evaporators with a lower evaporation enthalpy of water, resulting in that the refined SVG3, with a notable water surface architecture and an expanded evaporation area, achieved a steam generation rate of 2.13 kg m−2 h−1 under 1 Sun. Notably, SVG2 achieved a high evaporation rate of 2.43 kg m−2 h−1 with the combined energy input of 1 Sun and 6 V, significantly surpassing the rate of 1.96 kg m−2 h−1 without voltage input. The results indicate that electrical energy significantly enhances and synergizes with SVG, facilitating continuous operation both day and night through the combined use of solar energy and electrical input. This study offers insightful perspectives for the strategic design of multifunctional hydrogels for solar water evaporation.

Spider Silk-Inspired Hyaluronic Acid-Based Hydrogels with Superior Self-Healing Capability and Enhanced Strength.

Hyaluronic acid hydrogels are promising materials for diverse applications, yet their potential is hampered by limitations such as low self-healing efficiency and insufficient mechanical strength. Inspired by the heterogeneous structures of spider silk, we introduce a novel dual dynamically crosslinked network hydrogel. This hydrogel comprises an acylhydrazone-crosslinked network, utilizing aldehyde hyaluronic acid (AHA) and 3,3'-dithiobis (propionohydrazide) (DTP) as a first network, and a secondary network formed by hydrogen bonds-crosslinked network between tannic acid (TA) and silk fibroin (SF) with β-sheet formation. The hydrogel exhibits exceptional self-healing ability due to the dynamic and reversible nature of Schiff base bonds, disulfide bonds, and hydrogen bonds, achieving complete healing within 5 minutes. Additionally, the spider silk-inspired heterogeneous structures enhance mechanical properties. Furthermore, the incorporation of TA provides enhanced adhesion, as well as remarkable antibacterial and antioxidant properties. This innovative hyaluronic acid-based hydrogel, inspired by spider silk, offers a promising avenue to fortify both the mechanical strength and self-healing capabilities of hydrogels, thus expanding opportunities for applications in tissue engineering and biomedicine.

Innovative Synthesis of Photo-Responsive, Self-Healing Silicone Elastomers with Enhanced Mechanical Properties and Thermal Stability.

Photo-responsive materials have garnered significant interest for their ability to react to non-contact stimuli, though achieving self-healing under gentle conditions remains an elusive goal. In this research, an innovative and straightforward approach for synthesizing silicone elastomers is proposed that not only self-heal at room temperature but also possess unique photochromic properties and adjustable mechanical strength, along with being both transparent and reprocessable. Initially, aldehyde-bifunctional dithiophene-ethylene molecules with dialdehyde groups (DTEM) and isocyanurate (IPDI) is introduced into the aminopropyl-terminated polydimethylsiloxane (H2N-PDMS-NH2) matrix. Subsequently, palladium is incorporated to enhance coordination within the matrix. These silicone elastomers transition to a blue state under 254nm UV light and revert to transparency under 580nm light. Remarkably, they demonstrate excellent thermal stability at temperatures up to 100°C and show superior fatigue resistance. The optical switching capabilities of the silicone elastomers significantly affect both their mechanical characteristics and self-healing abilities. Notably, the PDMS-DTEM-IPDI-@Pd silicone elastomer, featuring closed-loop photo-switching molecules, exhibits a fracture toughness that is 1.3 times greater and a room temperature self-healing efficiency 1.4 times higher than its open-loop counterparts. This novel photo-responsive silicone elastomer offers promising potential for applications in data writing and erasure, UV protective coatings, and micro-trace development.

Tough Self-Healing Materials via In Situ Growth of Zeolitic Imidazolate Framework-8 Nanocrystals in Polymers.

Construction of self-healing materials with improved mechanical performanceis a great challenge. A strong and tough self-healing composite is fabricated via in situ growth of zeolitic imidazole framework-8 (ZIF-8) nanocrystals in imidazole-containing polymer networks. By adjusting the stoichiometric ratio of the zinc salt to 2-methylimidazole, composites with various mechanical performances are obtained. The existence of ZIF-8 nanocrystals via in situ growth in the polymer networks is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The zinc-imidazole interactions between the ZIF-8 nanocrystals and the polymer are confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The composites can repair themselves under mild conditions owing to dynamic zinc-imidazole interactions. The self-healing efficiency of composites can reach up to 91% under the condition of 60°C for 48h. In contrast to the pure zinc cation crosslinking system, the composite containing ZIF-8 nanocrystals prepared via in situ growth exhibited enhanced tensile strength and toughness by 43% and 100%, respectively. This study proves that incorporating the metal-organic frameworks(MOFs) materials into a self-healing system via an in situ growth strategy is highly promising for designing self-healing materials with improved mechanical performance.

Cross-scale interface engineering strategy to achieve self-healing antifouling material strength and toughness symbiosis

The incorporation of self-healing technology into antifouling coatings is crucial for the extension of their service life and durability. However, the challenge lies in the insufficient coexistence of strength and toughness hinders their long-term serviceability. Here, this study proposes a cross-scale interfacial engineering strategy for self-healing antifouling coatings inspired by the multiscale microstructure of natural biomaterials The strategy involves the in-situ growth of antifouling zinc-based metal–organic frameworks (Zn-MOF) within a self-healing polymer network constructed by multiple hydrogen bonds. The synergistic cross-scale interfacial interactions between Zn-MOF and the polymer molecules, combined with the intrinsic antifouling properties of Zn-MOF, significantly enhance the strength, toughness to 27.48 MPa, 277.81 MJ/m3, and benefit improving antifouling performance. Moreover, the molecular integration of Zn2+-pyridine coordination optimizes the microphase structure of the polymer matrix and embeds the advantage of its fast damage response, thereby further enhancing the robustness, and reaching self-healing efficiency to 91.74 % at 40 °C for 24 h. Overall, the proposed strategy represents a viable approach for the fabrication of highly resilient and tough self-healing antifouling coatings.