Excellent Self-healing Performance Research Articles

Fire-resistant and low-temperature self-healing bio-based hydrogel electrolytes based on peach gum polysaccharide/sisal nanofibers for flexible supercapacitors

The introduction of flame retardancy and low-temperature self-healing capacities in hydrogel electrolytes are crucial for promoting the cycle stability and durability of the flexible supercapacitors in extreme environments. Herein, biomass-based dual-network hydrogel electrolyte (named PSBGL), was synthesized with borax crosslinked peach gum polysaccharide/sisal nanofibers composite, and its application in flexible supercapacitors was also investigated in detail. The dynamic cross-linking of the dual-network endows the PSBGL with excellent self-healing performance, enabling ultrafast self-healing within seconds at both room temperature and extreme low temperatures. The PSBGL bio-based hydrogel electrolyte can maintain the integrity of the carbon layer structure with limiting oxygen index of 56 % after 60 s of combustion under a flame gun. Additionally, the PSBGL exhibits high ionic conductivity (30.12 mS cm−1), good tensile strength (1.78 MPa), and robust adhesion to electrodes (1.15 MPa). The assembled supercapacitors demonstrate a high specific capacitance of 187.8 F g−1 at 0.5 A g−1, with 95.9 % capacitance retention rate after 10,000 cycles at room temperature. Importantly, even under extreme temperatures of 60 °C and − 35 °C, the supercapacitors can also maintain high capacitance retention rates of 90.1 % and 86.5 % after 10,000 cycles. This work fills the gap between biomaterial design and high-performance flexible supercapacitors.

A multifunctional conductive organohydrogel as a flexible sensor for synchronous real-time monitoring of traumatic wounds and pro-healing process

Ion-conductive hydrogels (ICHs) offer promising applications in the realm of flexible bioelectronics due to their attributes, such as transparency, flexibility, tissue adhesion, and self-healing. However, it remains a challenge to integrate excellent material properties and bio-properties into ICHs-based smart wearables for intricate biomedical applications. Herein, a multifunctional conductive C-CST/PMC organohydrogel with stretchability, anti-freezing, self-healing, antibacterial, antioxidant, and biocompatibility was synthesized by catechol-conjugated chitosan (C-CS), silk nanofibrils (SNFs), tannic acid (TA), MgCl2/CaCl2, and polyvinyl alcohol (PVA), with a binary solvent system composed of ethylene glycol (EG) and H2O. The C-CST/PMC exhibited excellent mechanical properties (175 kPa stress and 330 % strain), anti-freezing capacity, moisture retention, self-healing performance, and high conductivity (1.76 mS/cm at 25 °C and 1.43 mS/cm at –18 °C). Moreover, we have employed this organohydrogel as a flexible strain sensor for monitoring human movements, achieving a high sensitivity (gauge factor (GF) = 1.20 at 100 % strain) and glorious fatigue resistance (>1000 cycles). Furthermore, the C-CST/PMC displayed good antibacterial, antioxidant, hemo-, and cytocompatibility. In vivo tests on diabetic rats have demonstrated that the C-CST/PMC organohydrogel effectively reduces inflammatory responses and promotes angiogenesis, consequently expediting wound healing. Notably, trials involving the use of this flexible sensor in a medical silicone bionic shoulder have indicated its potential as a wearable electronic device for real-time monitoring of human wound healing progress. Overall, this research contributes novel insights to the design and fabrication of multifunctional flexible sensors that synchronous pro-healing and real-time monitoring of traumatic skin.

Effect of acylhydrazone self-healing agents with different structures on the properties of SBS modified asphalt waterproofing membrane

To prepare SBS modified asphalt (SMA) waterproofing membrane with excellent self-healing performance, in this paper, four self-healing agents (ASHA-A, ASHA-B, ASHA-C, ASHA-D) with acylhydrazone bonds and carbon-carbon double bonds (CC) were synthesized, and were used to prepare self-healing SMA waterproofing membranes (SSMA-A, SSMA-B, SSMA-C, SSMA-D). The effects of ASHAs with different structures on the structure, high and low temperature properties, joint peel strength and self-healing performance of SSMAs were investigated. The Fourier transform infrared spectroscopy and fluorescence microscope results showed that acylhydrazone bonds of ASHAs were introduced into the chains of SBS molecules, and the SBS in SSMAs occurred crosslinking through the CC of ASHAs and SBS, the crosslinked network structures of SBS in SSMA-C and SSMA-D were denser and more complete because ASHA-C and ASHA-D contained more CC involved in the crosslinking reaction. The softening point and low temperature flexibility of SSMAs were enhanced by the formation of the SBS crosslinked network structure, and the optimum dosage of ASHAs was 0.6%. The joint peel strength of SSMA-A, SSMA-B, SSMA-C and SSMA-D increased by 26.68%, 31.25%, 49.52% and 56.97% compared to SMA. The introduction of acylhydrazone bonds with reversible fracture and rearrangement significantly improved the crack self-healing performance of SMA, the impermeability times of SMA, SSMA-A, SSMA-B, SSMA-C and SSMA-D were 13.28 min, 37.29 min, 42.53 min, 53.34 min and 59.67 min after self-healing at 40℃ for 8 h, which indicated that ASHA-D with benzene ring and multiple CC had the best improvement in self-healing performance of SMA.

Construction of self-healing multifunctional hyper-crosslinked hyperbranched polymer @ metal–organic polyhedra (HHMOP) membranes

The preparation of hybrid membranes composed of polymer matrix and porous materials is a hot topic. Herein, a highly reversible hyper-crosslinked hyperbranched polymer @ metal–organic polyhedra (HHMOP) membrane was designed and synthesized using hyperbranched polyamide amine (HPMA), UiO-66-NH2, diethylenetriamine, and terephthalaldehyde through a multi-component Schiff-base condensation reaction of aldehyde and amine groups. The structures of HHMOP membranes were characterized by FTIR, XRD, and SEM. The mechanical properties, thermal properties, reversible self-healing properties, and biological activity of the membranes were studied. Introducing HPMA as hyper-crosslinking monomer and UiO-66-NH2 as porous comonomers into the network resulted in HHMOPs membranes with multiple functionalities: flexibility, humidity sensitivity, self-healing capacity, antibacterial capacity and better mechanical properties than the original polyimine films. The tensional intensity and breaking elongation of HHMOP membrane has been remarkably ameliorated, with the maximum tensile strength reached 54.64 MPa. The membranes showed humidity-sensitive mechanical properties and excellent self-healing performance, with 91.35 % strength revovered after 24-hours at room temperature and a relative humidity of 60 %, indicating that HPMA has a significant impact on the humidity responsiveness and self-healing performance of HHMOP membranes. The HHMOP membrane also demonstrated good antibacterial activity against common food lethal bacteria like the gram-positive Staphylococcus aureus and gram-negative Escherichia coli. This work will greatly enrich the devise and preparation of versatile membranes and broaden the use of MOFs.

3D Printing Self-Healing and Self-Adhesive Elastomers for Wearable Electronics in Amphibious Environments.

To meet the demands of challenging usage scenarios, there is an increasing need for flexible electronic skins that can operate properly not only in terrestrial environments but also extend to complex aquatic conditions. In this study, we develop an elastomer by incorporating dynamic urea bonds and hydrogen bonds into the polydimethylsiloxane backbone, which exhibits excellent autonomous self-healing and reversible adhesive performance in both dry and wet environments. A multifunctional flexible sensor with excellent sensing stability, amphibious self-healing capacity, and amphibious self-adhesive performance is fabricated through solvent-free 3D printing. The sensor has a high sensing sensitivity (GF = 45.1) and a low strain response threshold (0.25%) and can be used to detect small human movements and physiological activities, such as muscle movement, joint movement, respiration, and heartbeat. The wireless wearable sensing system assembled by coupling this device with a bluetooth transmission system is suitable for monitoring strenuous human movement in amphibious environments, such as playing basketball, cycling, running (terrestrial environments), and swimming (aquatic environments). The design strategy provides insights into enhancing the self-healing and self-adhesive properties of soft materials and promises a prospective avenue for fabricating flexible electronic skin that can work properly in amphibious environments.

Preparation and properties of self-healing SBS modified bitumen with dynamic acylhydrazone bonds

Styrene-butadiene-styrene triblock copolymer (SBS) modified bitumen (SMB) with excellent self-healing performance not only saves resources, but is also important for the sustainable development of pavement and construction industry. In this paper, a self-healing agent (SHA) with acylhydrazone bond was synthesized, and the dynamic acylhydrazone bond was introduced into the SBS molecular chains to prepare the self-healing SMB (SHMB). The structure of SHA was characterized, and the physical properties, chemical structure, microstructure and self-healing performance of the SHMB were investigated. Fourier transform infrared (FTIR) spectra and nuclear magnetic resonance spectra demonstrated that SHA was successfully synthesized. The physical performances of SMB were significantly improved by SHA and its optimal dosage was 0.6 %. FTIR indicated that the dynamic acylhydrazone bond was introduced into the SBS molecular chains, and formed hydrogen bonds in SHMB. The fluorescence microscope showed that SHMB had a denser network structure than SMB. The crack healing observation indicated that the crack healing speed of SHMB was much higher than that of SMB. The break tensile performance recovery showed that the recovery rate of elongation at break (Rε) of SMB and SHMB were 14.38 % and 58.27 % after self-healing at 25℃ for 32 h, and the Rε of SMB and SHMB was elevated to 50.12 % and 92.58 % after self-healing at 40℃ for 4 h, which indicated that the introduction of dynamic acylhydrazone bonds greatly enhanced the self-healing ability of SHMB.

Silver sulfide anchored bismuth molybdate p-n heterojunction nano-coating with excellent photo-thermal self-healing performance

In this research, a self-healing nano-coating with excellent photo-thermal response to near-infrared (NIR) laser is prepared. This coating incorporates silver sulfide anchored bismuth molybdate (Ag2S@Bi2MoO6) into a shape memory epoxy resin to achieve for a good photo-thermal conversion capability. The Ag2S@Bi2MoO6 p-n heterojunction could photo-generate more electron-holes pairs under the NIR laser irradiation. Also, it shows a wider absorption range of visible light, leading to effectively absorb the light energy, generate enough heat to induce the shape memory recovery in the coating, and seal the scratch. The results indicate that the temperature of EP-1 % Ag2S@Bi2MoO6 coating has reached about 88 °C, while good self-healing and anti-corrosion properties with a self-healing rate of 88.41 % have been achieved. Furthermore, calculations based on Density Functional Theory and Finite Element Method pointed out that the formation of p-n heterojunction effectively has enhanced the photo-thermal effect. This research opens a new way for developing self-healing coatings with an ultra-fast response time and high self-healing efficiency.

PH-Responsive Graphene Oxide-Based 2D/3D Composite for Enhancing Anti-Corrosion Properties of Epoxy Coating.

The functionalized graphene oxide (GO)-based composites as fillers added into organic coatings are desired for realizing the longstanding corrosion protection of carbon steel. Here, the pH-responsive two-dimensional/three-dimensional (2D/3D) GO-based composite (ZIF-90-AAP/GO) was developed by environmentally friendly corrosion inhibitor 4-aminoantipyrine (AAP) anchored on the in situ growth of zeolite imidazolate framework-90 (ZIF-90) on the GO surface (ZIF-90/GO) through the Schiff base reaction. The active filler (ZIF-90-AAP/GO) was incorporated into an epoxy coating (EP) to obtain a high-performance self-healing coating on the surface of carbon steel. ZIF-90-AAP can greatly improve dispersion and compatibility of GO in EP. The low-frequency impedance modulus of ZIF-90-AAP/GO-EP can still reach up to 1.35 × 1010 Ω⋅cm2 after 40 days, which is about three orders of magnitude higher than that of the EP containing GO (GO-EP) relying on its passive and active corrosion protection. Meanwhile, ZIF-90-AAP/GO-EP exhibits excellent self-healing performance. The self-healing rate of ZIF-90-AAP/GO changes from negative to positive after 24 h, which results from the effective corrosion inhibition activity of ZIF-90-AAP for carbon steel based on the pH-triggered controlled release of AAP. The developed pH-responsive 2D/3D GO-based composite coating is very attractive for the corrosion protection of carbon steel.

Co-ordinated polyhedral oligomeric silsesquioxane and cyclodextrin on polyurethane elastomer with network topology for simultaneously improved fatigue-resistant and self-healable properties

Long-term usage can induce cracks on the surface or inside the polyurethane (PU) and cause fatigue damage, thus reducing the performance and lifetime of PU. It is therefore of great practical importance to impart fatigue resistance and self-healing ability to PU. However, the conventional covalent cross-linked network design with irreversible and rigid properties limits their fatigue resistance. Here, we have designed a highly ductile, fatigue-resistant and self-healing PU enabled by the synergistic effect of covalent network topology, dynamic reversible disulfide bonds and multiple hydrogen bond stacking. This judicious design yields excellent mechanical properties such as high tensile strength (7.38 MPa), high elongation at break (1159%) and high toughness (42.91 MJ·m−3). Notably, the PU successfully combines fatigue resistance with self-healing behavior. During 1000 cycles of stretch-release processes at 100% strain, the stress retention of the PU almost unchanged. Moreover, the PU achieves a high self-healing efficiency of 98% after self-healing at 80 ℃ for 2 h. The above-mentioned superiority enables the PU-based strain sensors to have a timely and stable output signal as well as excellent self-healing performance. Such a judicious strategy will facilitate the practical application of durable flexible electronics.

Composite Material with Excellent Thermal Management and Self-Healing Performance for Battery Temperature Control and Human Thermal Therapy

Composite Material with Excellent Thermal Management and Self-Healing Performance for Battery Temperature Control and Human Thermal Therapy

Tough, self-healing and injectable dynamic nanocomposite hydrogel based on gelatin and sodium alginate

Biomacromolecules based injectable and self-healing hydrogels possessing high mechanical properties have widespread potential in biomedical field. However, dynamic features are usually inversely proportional to toughness. It is challenging to simultaneously endow these properties to the dynamic hydrogels. Here, we fabricated an injectable nanocomposite hydrogel (CS-NPs@OSA-l-Gtn) stimultaneously possessing excellent autonomous self-healing performance and high mechanical strength by doping chitosan nanoparticles (CS-NPs) into dynamic polymer networks of oxidized sodium alginate (OSA) and gelatin (Gtn) in the presence of borax. The synergistic effect of the multiple reversible interactions combining dynamic covalent bonds (i.e., imine bond and borate ester bond) and noncovalent interactions (i.e., electrostatic interaction and hydrogen bond) provide effective energy dissipation to endure high fatigue resistance and cyclic loading. The dynamic hydrogel exhibited excellent mechanical properties like maximum 2.43 MPa compressive strength, 493.91 % fracture strain, and 89.54 kJ/m3 toughness. Moreover, the integrated hydrogel after injection and self-healing could withstand 150 successive compressive cycles. Besides, the bovine serum albumin embedded in CS-NPs could be sustainably released from the nanocomposite hydrogel for 12 days. This study proposes a novel strategy to synthesize an injectable and self-healing hydrogel combined with excellent mechanical properties for designing high-strength natural carriers with sustained protein delivery.

Stereogenic Harmony Fabricated Mechanoresponsive Homochiral Triphenylalanine Analogues with Synergistic Antibacterial Performances: A Potential Weapon for Dermal Wound Management.

The wound recovery phenomenon remains as one of the long challenging concerns worldwide. In search of user-friendly dressing materials, in this report, we fabricated a rational combinatorial strategy utilizing stereogenic harmony in a triphenylalanine fragment and appending it to δ-amino valeric acid at the N-terminus (hydrogelators I-VII) such that a potential scaffold could be fished out from the design. Our investigations revealed that all the hydrogelators displayed not only excellent self-healing performance as well as high mechanical strength at physiological pH but also mechanical stress-triggered gel-sol-gel transition properties. The structural and morphological investigation confirmed the presence of β-sheet-like assemblies stabilized by intermolecular H-bonding and π-π interactions. Moreover, these scaffolds showed substantial antibacterial as well as antifungal efficacy against common wound pathogens, i.e, four Gram-positive bacteria (Staphylococcus aureus, Streptococcus mutans, B. subtilis, E. fecalis), four Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, P. aerugonosa, Proteus spp.), and two fungal strains (C. albicans and A. niger). The manifestation of consistent antioxidant properties might be due to the enhancement of amphiphilicity in hydrogelators, which has led to the generation of reactive oxygen species (ROS) in a facile manner, a probable mechanism to damage the microbial membrane, the driving force behind the antimicrobial efficacy. Also, the constructs exhibited proteolytic resistance and remarkable biocompatibility toward mammalian cells. Thus, based on the above benchmarks, the homochiral hydrogelator IV was seived out from a pool of seven, and we proceeded toward its in vivo evaluation using full-thickness excisional wounds in Wister rats. The scaffolds also accentuated the re-epithelialization as well in comparison to the negative control, thereby facilitating the wound closure process in a very short span of time (10 days). Overall, our in vitro and in vivo analysis certifies hydrogelator IV as an ideal dressing material that might hold immense promise for future wound care management.

Investigation on self-healing polyurethane coating doped with lignin composites for protecting cementitious materials

Surface protective coatings are prone to cracking and failure due to the deformation of concrete structure itself and harsh service environment factors such as UV, ion erosion, and large temperature differences during the period of service. It is urgently required to develop new types of self-healing coatings to provide long-lasting protection for concrete structures and extend their service life. In this investigation, a lignin-based self-healing agent was prepared using aniline and lignin as raw materials. Its characterization was analyzed by SEM and FT-IR. By introducing the lignin-based healing agent and dynamic disulfide bonds, a new kind of self-healing polyurethane coating was prepared, and its self-healing ability was qualitatively and quantitatively evaluated, indicating that it had excellent self-healing performance. After self-healing process, the crack could withstand bending force. Moreover, with the increased temperature, the self-healing efficiency of tensile strength gradually increased, reaching a maximum of 86.42% at 60 ℃. Meanwhile, the self-healing efficiency of its elongation at break firstly increased and then gradually decreased, reaching a maximum of 93.77% at 40 ℃. This self-healing polyurethane coating had high hydrophobicity (139.4°) and excellent abrasion resistance. After 40 friction cycles, its hydrophobicity only decreased by 10.9% to 124.2°. In addition, this self-healing protective coating also showed excellent resistance to chloride ions, effectively protecting cementitious materials with the damaged surface. This work provides a new method for long-term protection of concrete structures.

Tung oil-based waterborne UV-curable coatings via cellulose nanofibril stabilized Pickering emulsions for self-healing and anticorrosion application

In this study, waterborne UV-curable coatings with self-healing properties based on transesterification were prepared using renewable biomass resources for anti-corrosion application. Tung oil (TO)-based oligomer (TMHT) was synthesized through Diels-Alder reaction of TO with maleic anhydride, subsequent ring opening reaction with hydroxyethyl acrylate (HEA), and final neutralize reaction with triethylamine. A series of waterborne UV-curable coatings were prepared from cellulose nanofibrils (CNF) stabilized TMHT-based Pickering emulsions after drying and UV light-curing processes. It is suggested that CNF significantly improved the storage stability of Pickering emulsions. The obtained waterborne UV-curable coatings with CNF of 1–3 wt% exhibited remarking coating and mechanical performance (pencil hardness up to 5 H, adhesion up to 2 grade, flexibility of 2 mm, tensile strength up to 11.6 MPa, etc.), great transmittance (82.3 %–80.8 %) and great corrosion resistance (|Z|0.01Hz up to 5.4 × 106 Ω·cm2). Because of the presence of the dynamic ester bonds in TMHT, the coatings exhibited excellent self-healing performance (78.05 %–56.34 %) at 150 °C without catalyst and external force. More importantly, the |Z|0.01Hz of the self-healing coating was higher than that of the scratched coating, indicating that the self-healing performance could extend the service life of the coating in corrosion resistant application.

Investigating the self-healing performance of cracked undersea constructions

The undersea construction has undergone long-term exposure to erosive high-pressure seawater. Hence, it has become urgent to meet long-term requirements for seepage resistance and corrosion resistance. The objective of this study was to delve into the feasibility of remedying capillary cracks narrower than 0.3 mm in concrete constructions by using self-healing properties of concrete within a marine environment. Through the test of pressurized water seepage, micro-examinations, and numerical simulations of low water-to-binder ratio concrete subjected to simulated marine conditions, this study investigated the impacts of initial crack width, hydrostatic pressure, and curing age on water permeability, crack width, splitting tensile strength, and free chloride content in cracked concrete. The findings revealed that the concrete exhibiting capillary cracks with a width of under 0.3 mm indicated excellent self-healing performance. Notably, the results indicated the decrease in the water permeability, the gradual decline in surface crack width, and a slight recovery of the splitting tensile strength. However, the chloride ion transport was less evident compared to seepage as fracture closure decreased. The healing indexes of cracked concrete were enhanced with the decrease in the initial crack width, the shortening of curing period, and the decline in hydrostatic pressure. Moreover, the results demonstrated that the seepage velocity negatively impacted concrete healing, while continuous hydration during the early stages of concrete formation positively affected the healing process. These results provided valuable insights for devising maintenance strategies for concrete structures exposed to seawater environments.

Novel Polyetherimide Dielectrics: Molecular Design, Energy Storage Property, and Self-Healing Performance.

The development of high-temperature resistant dielectrics with excellent dielectric properties and self-healing behavior is crucial for the application of metallized film capacitors. In this work, a series of polyetherimide (PEI) dielectric films are designed and fabricated. The introduction of polar groups is in favor to the increase of permittivity, and the flexible connection such as the ether group will facilitate the reduction of dielectric loss. Moreover, the oxygen elements are beneficial to the "self-healing" of metallized film capacitors. Consequently, the permittivity of 3.53-4.00, dissipation factor of 0.281-0.517%, and Weibull breakdown strength of 347-674MVm-1 are obtained for the PEI dielectrics. In addition, PEI-4 (BPADA-BAPP) and PEI-8 (BPADA-MDA) are selected to further investigate dielectric breakdown (150°C), electrical displacement-electric filed (D-E) loop (at room temperature and 150°C) as well as self-healing performance, which will evaluate their potential in practical applications. The results show that PEI-8 has stable breakdown field strength and high charge-discharge efficiency at elevated temperatures. Metallized film capacitor based on PEI-8 exhibits excellent self-healing performance, with pleasing self-clear morphology, high breakdown voltage, and reduced self-healing energy. Therefore, PEI-8 is considered as a potential candidate for metallized film capacitors applied under harsh conditions.

3D printable, anti-freezing, and rapid self-healing violet phosphorene incorporated hydrogel-based sensors for human motion detection

Conductive self-healing hydrogels, as an emerging flexible material, have been extensively studied in flexible sensors which have great application potential in the field of wearable electronic devices. However, hydrogels are prone to freezing at low temperatures, resulting in reduced or even lost flexibility, conductivity and self-healing properties. Besides, manufacturing method, processing time and cost of hydrogel-based sensors remain extremely challenging, hindering their application in complex and extreme environments. The hydrogel with excellent strain-sensing properties and outstanding anti-freezing properties was fabricated by 3D printing technology and solvent displacement method. The VP-SPB-EG hydrogel has excellent anti-freezing performance (−80 °C). In particular, this hydrogel exhibits excellent self-healing performance (120 s) at −80 °C. In addition, VP-SPB-EG hydrogel-based has high stretchability (1850 %) and sensitivity (GF: 27.82) can be used to detect strain changes caused by human joint movements. Therefore, this flexible hydrogel-based sensor has broad application prospects for wearable devices in extreme environments.

An antibacterial, highly stretched and self-healing polyurethane elastomer for flexible electronic devices

Broadening the range of practical applications of self-healing materials has become a research hotspot for the development of durable and smart materials. This study the development of a hydrogen bond-rich of self-healing elastomer, formed by the combination of disulfide and diazolidinyl urea (DU) cross-linked polyurethane polymers (PDD). The prepared polyurethane elastomer material possessed extremely high mechanical properties (including a stress of 25 MPa and high toughness of 306 MJ/m3). Besides, PDD exhibited an excellent self-healing performance. Even if it is subjected to long-term tensile deformation or extreme strain, it could recover almost completely to its initial state within 12 h in a 60 °C environment. In addition, the synergistic effect of diazolidinylurea and element S on the polymer film gave the material excellent antimicrobial properties. Finally, we added carbon nanotubes into the polyurethane system and assembled them into smart sensors for applications in flexible electronic devices. The versatility of this sensor has been demonstrated in human motion applications.

Graphene composite self-healing antifog/frost-resist transparent coatings with zwitter-wettability

Self-healing materials achieve both durability and simplified maintenance by restoring their structure and function. However, self-healing materials utilizing surface hydrophilicity are considered incompatible with zwitter-wettability properties. Therefore, further investigation is needed to fabricate antifogging coatings that combine zwitter-wettability and self-healing properties. In this study, we demonstrated that polymer multilayer graphene composite coatings exhibit simultaneous antifogging and self-healing properties. We achieved a uniform dispersion of an aqueous solution of graphene by directly dispersing in a strong acid polymer and a uniform dispersion of graphene in the membrane via layer-by-layer self-assembly without any post-treatment, enabling precise control of hydrophobicity and water absorption of the membrane. The fabricated layer-by-layer coatings exhibited zwitter-wettability and self-healing performances comparable to those of previously reported systems. The maximum water droplet contact angle on the surface was 99° The 20-bilayer coating also exhibited excellent self-healing performance, closing 100 μm scratches within approximately 60 s and flattening the surface within approximately 300 s of exposure to water. In the antifogging tests, the coatings demonstrated high resistance to harsh cooling environments and exhibited excellent antifogging performance. This study provides a new zwitter-wetting strategy that combines self-healing and antifogging properties, providing an exceptional option for the development of next-generation surface coatings.

A damage-tolerant, self-healing and multifunctional triboelectric nanogenerator

Triboelectric nanogenerators (TENGs) are subjected to repeated contact and separations during operation, which inevitably cause damage from mechanical forces, leading to interface mismatch and function loss. Although self-healing property has been utilized to prolong the service life of flexible TENGs, triboelectric nanogenerators which can work stably in extreme mechanical environments have not been developed. Herein, we report a flexible single-mode triboelectric nanogenerator named V-PANI-TENG which not only have strong damage-tolerant ability including puncture-resistant ability to resist sabotage and tear-resistant ability to defend further crack propagation, but also show excellent self-healing performance upon damage based on the well-designed tribolayer PMBEug-OH-V-2–4 and electrode material PMBEug-OH-PANI-20%. Moreover, the V-PANI-TENG can also be used as an efficient self-powered sensor to monitor the movement of human body or detect the road surface roughness. Given the extraordinary durability and unprecedented applications resulting from novel material designs, this work provides an effective way to develop triboelectric nanogenerators which can work stably in extreme mechanical environments and broaden the application scenarios of triboelectric nanogenerators.