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Dehydration has been a key limiting factor for the operation of conductive hydrogels in practical application. Here, we report self-healable ionic skins that can self-regulate their internal moisture level by capturing extenral moistures via hygroscopic ion-coordinated polymer backbones through antipolyelectrolyte effect. Results show the ionic skin can maintain its mechanical and electrical functions over 16 months in the ambient environment with high stretchability (fracture stretch ∼2216 %) and conductivity (23.5 mS/cm). The moisture self-regulating capability is further demonstrated by repeated exposures to harsh environments such as 200°C heating, freezing, and vacuum drying with recovered conductivity and stretchability. Their reversible ionic and hydrogen bonds also enable self-healing feature as a sample with the fully cut-through damage can restore its conductivity after 24 h at 40 % relative humidity. Utilizing the ionic skin as a building block, self-healing flexible piezoelecret sensors have been constructed to monitor physiological signals. Together with a facile transfer-printing process, a self-powered sensing system with a self-healable supercapacitor and humidity sensor has been successfully demonstrated. These results illustrate broad-ranging possibilities for the ionic skins in applications such as energy storage, wearable sensors, and human-machine interfaces.

The research in this paper focuses on the development of a recyclable, efficient and environmentally friendly fireproofing material for mining applications. Therefore, we formulated a novel composite gel named sodium alginate composite gel (PBSL-3) with sodium alginate, alkali lignin and polyvinyl alcohol as raw materials and borax as cross-linking agent. The success of the synthesis of PBSL gel material was verified by scanning electron microscopy and infrared spectroscopy experiments. The good self-healing and ability of PBSL-3 was verified by self-healing, thermal stability and rheological performance experiments; The material has a moderate viscosity and exhibits suitable rheological properties at different shear rates, making it suitable for pipeline transportation; In addition, the weight loss of the gel material was only 64.43% at the programmed warming to a temperature of 160°C, presenting a lesser rate of weight loss, and the material lost only 58% of its weight at temperatures up to 800°C. The flame retardancy of the PBSL-3 gel material was verified by programmed warming experiments and small-scale fire extinguishing experiments. The experimental results showed that the material critical temperature of the coal samples treated with the material was delayed from 100°C to 130 °C, and the CO and C2H4 gas inhibition was 41.98% and 58.12%, respectively, and the flame retardancy was 56.41% at a temperature of 200°C. Small-scale fire extinguishing experiments show that the overall fire extinguishing effect of PBSL gel material is better, and it can effectively extinguish spontaneous coal combustion fires. [ABSTRACT FROM AUTHOR]

With the waste of resources caused by human activities, it has gradually become an increasingly prominent social problem. The development of self-healing polymers in the field of insulation has attracted widespread attention. Develop polymer matrices with efficient healing efficiency and sound insulation properties to achieve green and sustainable resource conservation. In addition, improving the dielectric properties of intrinsic self-healing matrices has been a hot topic. In this work, we developed a new PEI matrix-modified self-healing polymer substrate that provides a breakdown field strength of 240 kV/mm and self-healing properties at room temperature, this has significantly improved the dielectric properties over other previously reported self-healing polymers. In addition to the abovementioned performance, we found significant differences in thermodynamic behavior in the synthesized end-modified polymers. By dielectric characterization (LCR), the breakdown composite can be left at room temperature for 60 min, and the material can recover 80 % of the initial properties without external intervention(This is demonstrated by the fact that its DC conductivity at 60 min of autonomous healing was significantly changed from that of the freshly electrically pierced DC conductivity and remained around 5.38 × 10−11 S/cm for a longer period of time thereafter). The microscopic morphology of the modified PEI matrix was observed by scanning electron microscopy (SEM) and EDS surface elemental analysis, which further supports the existence of metal coordination structures. These findings can further deepen the thinking of self-healing dielectric composites. The work inspired by this may break the limits and take self-healing composite dielectric materials to a new height. [ABSTRACT FROM AUTHOR]

This article introduces a new method in which tung oil is employed as a bio‐friendly curative substance enclosed within melamine‐urea‐formaldehyde microcapsules. Due to the high reactivity of melamine, particle agglomeration can occur. To tackle this issue, this study focuses on optimizing the quantity of emulsifiers to achieve the best microcapsules with 15% melamine in the shell structure without particle agglomeration. The impact of melamine content and the quantity of emulsifier on the morphology of the synthesized microcapsules, the reaction yield, core content, and the hardness of the microcapsule shell were investigated. The presence of tung oil in melamine‐urea‐formaldehyde microcapsules was proven by Fourier transform infrared spectroscopy (FT‐IR). Field emission scanning electron microscopy (FESEM) revealed the spherical morphology of the capsules with a mean diameter of 2.29 μm. UV–vis analysis and nano‐indentation tests were used to evaluate the core content and the hardness of the result microcapsules, respectively. Finally, one sample, as the best microcapsule, was dispersed in an alkyd‐based resin in the amount of 1, 2.5, and 5 wt% and applied on a steel substrate for its ability to prevent corrosion. The study also highlights the adverse effect of excessive capsule usage in the resin, as demonstrated by reduced resin adhesion to the substrate, according to electrochemical impedance spectroscopy (EIS) and salt spray tests. The study found that the best long‐term anticorrosion properties are achieved by including 1 wt% of microcapsules in an alkyd resin. [ABSTRACT FROM AUTHOR]

For the first time, functionalized okra gum with multi-aldehyde groups (OG-CHO) and carboxymethyl chitosan (CMCh) is used to create injectable hydrogels (IHs) via Schiff base reaction at 37 °C. Gelation time is optimized based on the ratio of aldehyde groups of OG-CHO to amine groups of CMCh (9 ± 3 to 2 ± 1 min). Physical characteristics such as gel content (84 ± 2) and porosity (66 ± 3) are assessed. The syringeability, injectability, and self-healing properties are evaluated qualitatively and quantitatively using a rheometer. Structural analysis is carried out by FT-IR and 1H-NMR spectroscopy, while surface morphology and pore size (80 ± 5 µm) are examined via SEM. The swelling ratio is studied in the gel state of the IH in phosphate buffer saline (PBS) at varying pH levels of 5.5, 7.4, and 8.5, revealing a decrease in swelling ratio with increasing pH from 5.5 to 7.4 (75 ± 24 to 635 ± 20%), followed by an increase in swelling at pH 8.5 (724 ± 18.5%). Ciprofloxacin is employed as a model drug for release assays, and drug release behavior in gel forms of IH across different wound pH ranges is evaluated. The swelling and drug release behavior is described using the Korsmeyer–Peppas model, which shows non-Fickian diffusion. Furthermore, biocompatibility (cell viability > 90%), antibacterial assay, and in vitro degradation (~ 98%) are also assessed. [ABSTRACT FROM AUTHOR]

The use of microcapsules as preservative vessels for healing materials has led to a great revolution in the repair of materials. Microcapsules have been used in medicine, agriculture, metallurgy and mechanics. In civil engineering applications, microcapsules are usually used for the self-healing of concrete, asphalt and cementitious materials. Concrete and cement are widely used in civil engineering and are the predominant construction materials worldwide. The objective of this study was to design and produce urea–formaldehyde microcapsules for the recovery of reactive powder concrete (RPC). It was found that RPC specimens with and without microcapsules exhibited different behaviours. All of the RPC specimens containing microcapsules were found to have lower strengths than specimens without microcapsules. The smallest reductions in compressive strength were observed in specimens with a microcapsule content of 4–6% by weight of cement. The healing ratio of compressive strength increased with an increase in the weight percentage of microcapsules. Scanning electron microscopy and energy-dispersive spectroscopy were used to observe the process of crack healing, and the results showed that the cracks were filled with healing products. [ABSTRACT FROM AUTHOR]

This work examines the effect of temperature on the self-healing of asphalt mixture, and various laboratory tests were performed to find out qualitative and quantitative properties of asphalt material. Asphalt fatigue life and bending strength were determined using a three-point bending test and a four-point beam fatigue test. Test specimens were heated at various temperatures ranging from 20°C to 40°C for various periods, including the 20, 40, 60, 80, and 100 s. The strength recovery ratios at temperatures 20°C, 25°C, 30°C, 35°C, 40°C were 7%, 30%, 36%, 40%, 45%, respectively. The maximum healing index values for bitumen with penetration grades of 60/70 and 80/100 were 0.4 and 0.5 at temperatures between 37°C and 40°C. A 60 s period was chosen as the ideal period for achieving the highest recovery ratio for both bitumen specimens. It was observed that critical factor affecting the asphalt's capacity for self-healing is temperature, and the maximum healing index was found at temperatures between 37°C and 40°C. [ABSTRACT FROM AUTHOR]

Hot-mix asphalts are composite materials with self-healing properties: cracks in pavements constructed with these asphalts can close without external help. However, this self-healing process is slow, and cracks may reopen quickly. To increase the self-healing ratio and accelerate the healing process, capsules containing two different types of waste oil (vegetable and mineral oil) were added to the mixture at four different proportions (0.25%, 0.50%, 0.75%, and 1.00% by weight of the mixture). This research evaluated the effect of the capsule addition on the strength of the mixture against cracking. Experiments using samples with added semicircular capsules and samples containing no added capsules were carried out according to the linear elastic and elastic–plastic fracture mechanical principles. The self-healing properties of the hot-mix asphalt were determined. The results showed that the highest strength against cracking at low temperature was found in the sample with a proportion of 0.25% capsules of both types (waste vegetable and mineral oil). In addition, the oil released from the capsules increased the self-healing properties of the hot-mix asphalt. Samples fractured at 0°C had better healing than the samples fractured at 25°C. [ABSTRACT FROM AUTHOR]

Mechanical as well as durability properties are pivotal for any type of concrete which gets adversely affected due to cracks that may form due to loading beyond its capacity. Concrete has the intrinsic property to heal itself to some extent but not fully as the passive form of autogenous healing plays an inferior role for a complete repair of a cementitious material. The self-healing capabilities can be enhanced by adding chemical admixtures, polymers, and bacteria strains induced calcium carbonate precipitation, etc. In this paper, the advancements in the development and performance of self-healing concrete using chemical admixtures, polymers, and bacteria strains are reviewed. This systematic review includes the available experimental tests and methodologies investigating self-healing efficiency over the last decade. Further, this review focussed on self-healing materials, the ideology, and opinions of those in the construction field on the direction of self-healing concrete for future applications. It is yet not possible to predict the most appropriate technique, however, a generalized opinion about the effectiveness of the different approaches has been illustrated. [ABSTRACT FROM AUTHOR]

This paper investigates the intrinsic ability of PVA fiber-reinforced cementitious composites to re-establish the durability properties of the uncracked state. Comparative chloride penetration tests are used as a direct measure to quantify the effect of self-healing on the chloride penetration resistance after cracking. Two different composites with cement to fly ash ratios of 1:1.5 and 1:2.0 were studied under the influence of healing periods of up to 28 days. After inducing cracks between 100 and 120 μm, samples were exposed to chlorides for 72 h and the resulting chloride penetration depth was compared to the unhealed state. Based on this procedure, a durability recovery index was proposed to quantify the material's ability to re-establish its function as a protective layer after cracking. Results show that after 14 days of self-healing, chloride penetration through cracks was reduced between 81% and 99%. An extended healing period of 28 days leads to further reduction of the penetration depth to 84%–100%, indicating that most of the reaction takes place within the first 14 days of healing. While the stiffness recovery analysis showed that increasing cement content by 20% correlated with the formation of stronger healing products, no significant difference was found regarding crack closure. [ABSTRACT FROM AUTHOR]

A novel room‐temperature flexible, self‐healing PCM (denoted as PEG/PHMAC) based on gel skeleton was prepared in one‐pot free‐radical polymerization by using acrylic acid (AC) and hydroxyethyl methacrylate (HM) as monomers and polyethylene glycol (PEG) as phase change component and solvent. The as‐prepared samples exhibit excellent flexibility with a bending angle of up to 120° without fracture at room temperature, playing the role of the first barrier to effectively alleviate material fracture and failure caused by stress accumulation; in addition, because of the abundant hydrogen bonds in the material, it demonstrates outstanding self‐healing ability that deep rift can be quickly repaired within 30 min after the phase change, acting as the second barrier to self‐heal the cracks of PCM generated during long‐term heat storage/release cycles. Apart from that, these materials also show extraordinary antileakage and shape‐stable property without observation of any leakage or deformation at temperature much higher than the phase change temperature. It is also proved that this gel is suitable to act as adsorption skeleton of other PEG with different molecular weight and melting point feasible for different application scenarios. With so many merits, it is expected to provide some innovative ideas for the progress of PEG‐based PCM. [ABSTRACT FROM AUTHOR]

Self‐healing binder is a prospective and efficient strategy to alleviate volume expansion of silicon (Si) anodes. However, excellent mechanical strength and healing ability tend to be mutually exclusive, due to enhanced tensile stress limit by twining polymer chains, while inhibiting polymer diffusion rate and inducing healing failure by blocked chains. Herein, inspired by the planning course of boat and paddles, a novel self‐healing binder (PVA‐4FBA‐PEI) is designed and synthesized with mobile parallel structure and twining‐blocked characteristics. The boat‐like intermediate (4‐formylphenyl) boronic acid (4FBA) blocks entanglement of poly(vinyl alcohol) (PVA) and poly(ethyleneimine) (PEI) chains, where two parallel chains as paddles can simultaneously form to ensure rapid diffusion of chains during bond breakage. Remarkably, it endows dynamic synergistic covalent bonds via C═N and B─O─C junctions within 4FBA, providing the binder with an ultrafast self‐healing time of merely 2 min. Moreover, the binder integrates superior plasticity and flexibility of each chain, showing a high tensile strength (14.4 MPa) and stretchability (1163%) among state‐of‐the‐art polymer binders, thus significantly improving structural integrity and electrochemical stability of Si anode during cycling. This work proposes a dynamic reversible structure via figurative molecular coordination, affording a rational viewpoint on synergetic functionalities of polymer binders for Si anodes. [ABSTRACT FROM AUTHOR]

The design of stiffness‐changeable synthetic materials that can mimic their biological counterparts in the production of adaptable structures and functions is highly important but remains challenging. Here, the development of a bioinspired intelligent material composed of a deep eutectic solvent (DES) and an ionically crosslinked polymer network that is capable of switching reversibly between hard plastic and soft elastic states in response to water is reported. The eutectogel stiffness can be dramatically switched and flexibly regulated by water, which can activate salt ionization and shield the ionic crosslink. This design principle is extensively applied to multiple polymers, producing a series of bistate materials that exhibit water‐regulated capabilities ranging from self‐healing, shape memory, remolding, antifreezing, anticompressing, and stretchability to conductivity. These bistate materials are used for diverse functions, such as performing mechanical tasks, sensing and monitoring human movements, lighting LEDs, and outputting signals. This work opens an avenue for the development of next‐generation stiffness‐changeable materials with diverse functionalities for various designed applications. [ABSTRACT FROM AUTHOR]

The interplay between crystal ordering and stretchability is frequently encountered in contemporary materials science, particularly in the case of ferroelectrics. The inherent dilemma arises when these materials need to withstand repetitive mechanical deformations or stretching without sacrificing their crystal integrity, all while retaining their remarkable ferroelectric properties and even exhibiting self‐healing capabilities. This complexity further presents a significant challenge in the design and engineering of mechanically rigid molecular ferroelectric crystals, particularly for applications where both precise crystalline structure and mechanical adaptability are crucial. In this study, the humidity‐controlled expansion and contraction, dissolution, and recrystallization of a self‐assembled molecular ferroelectric‐in‐hydrogel framework are reported. Self‐healing ferroelectric‐in‐hydrogel networks exhibit a recyclable humidity‐tailored ionic conductivity from 2.86 × 10−6 to 1.36 × 10−5 S cm−1, facilitating the stretchable piezoelectric sensing. Additionally, the dynamic bond reforming interactions are observed, leading to the tailoring of Young's modulus from 452 to 170 MPa, maintaining ferroelectricity under a strain of 20% with a piezoelectric coefficient of 15.7 pC N−1. Upon lattice contraction, the molecular contacts undergo reforming, leading to the restoration of stretchable ferroelectrics/piezoelectrics and paving the way for stretchable bioelectronics for full‐body motion monitoring. The capabilities highlighted here open avenues for stretchable and self‐healing ferroelectric‐in‐hydrogel bioelectronic technologies. [ABSTRACT FROM AUTHOR]

Highlights This research aims to investigate the low‐velocity impact (LVI) response and self‐healing performance of carbon fiber composite laminates (NL) containing staggered hybrid polyamide nanofiber veils. Carbon fiber‐reinforced polymer (CFRP) composites are widely used in many industries, but they are sensitive to LVI damage and there is a lack of research on repair, which restricts their development. In the research, NL samples were prepared, and four impact energies of 6.6, 9.4, 12.2, and 15.0 joules were selected. Ultrasonic C‐scan detection, microscopic observation and mechanical property tests were carried out. The results show that the NL samples have smaller damage areas and degrees, indicating that the veils enhance the impact resistance; the damage repair efficiencies of the NL samples at different energies are 48.3%, 36.2%, 29.7% and 16.8% respectively; when the impact energy is lower than 13.9 J, the flexural strength of the repaired NL samples can be restored to more than 80% of the original strength. These results are of great significance. The improvement of the impact resistance of composites by hybrid polyamide nanofibers can solve the problem of CFRP's sensitivity to LVI damage, and the self‐healing ability provides a new approach to damage treatment, having broad application prospects in aerospace, shipbuilding and other industries. Hybrid veils enhance impact toughness, reducing damage area and severity. Veils enable self‐healing, repair impact damage, and enhance reusability. Repair efficiency is higher at lower impact energy levels. [ABSTRACT FROM AUTHOR]

Dental restorative resin composites are widely used to repair tooth decay owing to attractive esthetics, adequate mechanical properties and minimally invasive tooth structure preparations. Nevertheless, dental restorative resin composites still face challenges because of their relatively high failure rate and short lifespan caused by secondary caries and bulk fracture. Thus, attempts have been carried out to explore a new generation of dental restorative resin composites with antibacterial, remineralizing, and self-healing capabilities to inhibit bacteria and lengthen the lifetime of the restorations. Such novel restorative composites can inhibit bacterial activity, reduce acid production, promote mineral regeneration and present a renewable advantage to achieve a higher performance, which are inspiring and provide support for further basic and clinical research. In this review, antibacterial dental restorative resin composites are first introduced, followed by remineralizing, self-healing, and multifunctional dental resin composites with two or more of the functions mentioned above. Meanwhile, we explain the mechanism of the corresponding dental restorative resin composites and describe their characteristics. Finally, we conclude and put forward prospects. This review will attract both researchers and clinicians in this field and help to provide innovative ideas to design new restorative resin composites for biomedical applications. [ABSTRACT FROM AUTHOR]

Earthquakes present formidable challenges to structural stability, driving the need for ongoing advancements in construction methodologies. This review highlights the crucial role of Geopolymer Concrete (GPC) in enhancing earthquake resistance and addresses the need for innovative solutions. The review begins with an overview of the importance of earthquake-resistant construction practices, emphasizing that the next generation of GPC can increase flexural strength by up to 30% compared to conventional GPC concrete when incorporating nanomaterials such as nano-Al2O3, nano clays, and nano-SiO2. A detailed survey of current earthquake-resistant strategies reveals that while traditional concrete is susceptible to chloride attacks, GPC demonstrates a 37% lower vulnerability and significantly improved durability under harsh environmental conditions. The paper presents real-world case studies where GPC has been successfully implemented in seismic applications, illustrating effective enhancements in structural resilience metrics. The review then explores various emerging strategies for earthquake-resistant GPC, elucidating their unique features and advantages for seismic applications. Real-world case studies and examples illustrate the practical success and effectiveness of these next-generation strategies in improving structural resilience. The paper also outlines performance evaluation criteria for seismic structures, showing how these new approaches offer notable improvements over traditional methods. Challenges associated with implementing these advanced strategies are discussed, along with innovative solutions and recent advancements in the field. A comparative analysis of traditional and next-generation approaches highlights their respective benefits and potential drawbacks. The review concludes with an outline of future research directions and prospects for further enhancing GPC structures against seismic forces. This review consolidates key findings and underscores the transformative potential of next-generation strategies in earthquake-resistant construction. [ABSTRACT FROM AUTHOR]

Flexible luminescent materials are usually in the form of gels and films. Solid‐state films have advantages in practical applications due to their long‐term stability. However, the fabrication process by conventional methods remains laborious and unsustainable. Here, a facile and green route is reported for fabricating flexible luminescent films via an elegant solid‐phase molecular self‐assembly design. First, Eu3+/Tb3+‐based metallosupramolecular coordination polyelectrolytes (MEPEs) and tetraphenylethylene (TPE)‐based MEPEs are designed with an antenna bis‐ligands to get individual R, G, and B emission. Then, by repeatedly pressing the MEPEs‐cetyltrimethylammonium bromide (CTAB) precipitates, obtained from their mixing aqueous solutions, R, G, and B emission films are obtained at room temperature, respectively. The emission color can be simply tuned by adjusting molar ratio of Eu3+: Tb3+: TPE. Notably, humidity‐responsive white emission film is obtained when Eu3+: Tb3+: TPE = 3:1:2.5. Owing to the dynamic coordination and electrostatic interaction, which can be activated by hydrating water, these films can be facilely reprocessed and self‐healed with the aid of water at room temperature. It is hoped that this approach to fabricate flexible supramolecular luminescent films can be applied to design various advanced functional soft materials. [ABSTRACT FROM AUTHOR]

In this study, the practical application of self-healing asphalt mixtures incorporating steel wool fibers and induction heating was investigated, expanding upon previous research that primarily assessed the self-healing properties rather than optimizing the heating process. Specifically, the aim was to enhance the induction heating methodology for a semi-dense asphalt concrete mixture (AC 16 Surf 35/50 S). In this research, the induction heating parameters were refined to improve the self-healing capabilities, focusing on the following three key aspects: (i) energy consumption, (ii) heating rate, and (iii) heating homogeneity. The findings reveal that the current intensity, the percentage of ferromagnetic additives, and coil shape are critical for achieving optimal heating conditions. Higher current intensity and additive percentage correlate with improved heating speed and reduced energy consumption. Additionally, variations in coil shape significantly influence the heating uniformity. Although asphalt mixtures with steel slag coarse aggregates exhibit slightly higher specific heat, this aggregate type is preferable for sustainability, as it allows for the recycling of industrial waste. The optimized mixtures can rapidly reach high temperatures, facilitating effective crack repair. This innovation offers a durable, environmentally friendly, and cost-effective solution for road maintenance, thereby enhancing the longevity and performance of asphalt pavements. [ABSTRACT FROM AUTHOR]

Recently, renewable bio‐based materials have received more and more attention due to environmental issues such as global warming and ecosystem destruction. In the present work, a series of isosorbide‐based bioelastomers poly(isosorbide carbonate‐co‐butanediol aliphatic esters)s (PICBAs) are synthesized by a facile and economical two‐step melt polycondensation. Due to the slightly self‐crosslinking reaction of isosorbide, PICBAs exhibit excellent tensile strength and self‐healing ability, the mechanical properties of PICBAs can recover over 95% after 48 h under room temperature. In addition, PICBAs can stick different substances, such as glass, rubber, plastic, and stones, and show better adhesive performance than 3M commercially available double‐sided tape. Consequently, isosorbide‐based bioelastomers PICBAs are of great potential to be used as environmentally friendly pressure‐sensitive adhesives (PSA) in the future. [ABSTRACT FROM AUTHOR]

Catalyst‐free, radical‐based reactive processing is used to transform low‐density polyethylene (LDPE) into polyethylene covalent adaptable networks (PE CANs) using a dialkylamino disulfide crosslinker, BiTEMPS methacrylate (BTMA). Two versions of BTMA are used, BTMA‐S2, with nearly exclusively disulfide bridges, and BTMA‐Sn, with a mixture of oligosulfide bridges, to produce S2 PE CAN and Sn PE CAN, respectively. The two PE CANs exhibit identical crosslink densities, but the S2 PE CAN manifests faster stress relaxation, with average relaxation times ∼4.5 times shorter than those of Sn PE CAN over a 130 to 160 °C temperature range. The more rapid dynamics of the S2 PE CAN translate into a shorter compression‐molding reprocessing time at 160 °C of only 5 min (vs 30 min for the Sn PE CAN) to achieve full recovery of crosslink density. Both PE CANs are melt‐extrudable and exhibit full recovery within experimental uncertainty of crosslink density after extrusion. Both PE CANs are self‐healable, with a crack fully repaired and the original tensile properties restored after 30 min for the S2 PE CAN or 60 min for the Sn PE CAN at a temperature slightly above the LDPE melting point and without the assistance of external forces. [ABSTRACT FROM AUTHOR]

Highlights Ice accretion is a huge concern for many wind blades installed in colder regions. The approach of active de‐icing systems based on coatings has been recently quite explored. Nevertheless, the concern about an external electrically conductive layer leads to the need to develop multilayer insulating/conductive coatings. For this purpose, a novel multilayer coating consisting of a 3D printed carbon nanotube (CNT) and graphene nanoplatelet (GNP) reinforced nanocomposite is proposed, covered by a top coating consisting of a PCL‐based epoxy blend. Here, the CNT/GNP layer presents outstanding Joule heating capabilities due to the enhanced electrical conductivity, which increases significantly when increasing the filler content without drastically affecting the quality of the printed ribbons. More specifically, the temperature reached was about 140°C when applying 30 V for the 4 wt.%CNT and 6 wt.%GNP reinforced specimens. In this regard, this resistive heating can promote the thermal stimulus needed to activate de‐icing and self‐healing mechanisms on the epoxy/PCL top layer. Healing efficiencies obtained by the Joule effect reached up to 90% efficiency in comparison to convective heating, which showed a 68%, explained by the improved heating transfer from the CNT/GNP layer when applying the resistive heating. Finally, a proof‐of‐concept test as a de‐icing system showed a complete ice removal within 2.9 min when applying the resistive heating in the intermediate CNT/GNP layer, proving the multifunctionality of the proposed multilayer coating for self‐heating and self‐healing applications. A multilayer coating with self‐healing and de‐icing capabilities was successfully developed. Great combination of 3 min de‐icing time and 90% self‐healing efficiency. Novel inner 3D printed layer allows higher CNT/GNP contents than traditional ones. A multilayer approach with optimized nanoreinforced area required. [ABSTRACT FROM AUTHOR]

[Display omitted] Stone-built cultural heritage faces threats from natural forces and anthropogenic pollutants, including local climate, acid rain, and outdoor conditions like temperature fluctuations and wind exposure, all of which impact their structural integrity and lead to their degradation. The development of a water-based, environmentally-friendly protective coatings that meet a combination of requirements posed by the diversity of the substrates, different environmental conditions, and structures with complex geometries remains a formidable challenge, given the numerous obstacles faced by current conservation strategies. Here we report the structural, electrical, and mechanical characterization, along with performance testing, of a nanostructured hydrophilic and self-healing hybrid coating based on hydroxyapatite (HAp) nanocrystals and polyelectrolyte multilayers (PEM), formed in-situ on Greek marble through a simple spray layer-by-layer surface functionalization technique. The polyelectrolyte-hydroxyapatite multilayer (PHM) structure resembled the design of naturally forming trabecular bone, attained at a short procedural time. It exhibited chemical affinity, aesthetical compatibility and resistance to weathering while offering reversibility. The proposed method is able to generate micron-sized coatings with controlled properties, such as adhesion and self-healing, leading to less weathered surfaces. Our results show that the PHM is a highly effective protective material that can be applied for stone protection and other similar applications. [ABSTRACT FROM AUTHOR]

The rapid advancement in attractive platforms such as biomedicine and human‐machine interaction has generated urgent demands for intelligent materials with high strength, flexibility, and self‐healing capabilities. However, existing self‐healing ability materials are challenged by a trade‐off between high strength, low elastic modulus, and healing ability due to the inherent low strength of noncovalent bonding. Here, drawing inspiration from human fibroblasts, a monomer trapping synthesis strategy is presented based on the dissociation and reconfiguration in amphiphilic ionic restrictors (7000‐times volume monomer trapping) to develop a eutectogel. Benefiting from the nanoconfinement and dynamic interfacial interactions, the molecular chain backbone of the formed confined domains is mechanically reinforced while preserving soft movement capabilities. The resulting eutectogels demonstrate superior mechanical properties (1799% and 2753% higher tensile strength and toughness than pure polymerized deep eutectic solvent), excellent self‐healing efficiency (>90%), low tangential modulus (0.367 MPa during the working stage), and the ability to sensitively monitor human activities. This strategy is poised to offer a new perspective for developing high strength, low modulus, and self‐healing wearable electronics tailored to human body motion. [ABSTRACT FROM AUTHOR]

Highlights Wind turbines are subjected to extreme weather and load conditions; hence, high strength and impact resistance are required. Furthermore, wind turbine blades can be subjected to impact loads such as bird strikes, resulting in the formation of microcracks. Self‐healing capsules can be used to mend turbine blades for microscale damage. The incorporation of self‐healing capsules may cause a decrease in the mechanical characteristics of the composites prior to impact resistance, which can be compensated for with efficient fillers such as silicon carbide whiskers (SiCw). Thus, a novel hybrid composite structure is examined with the advantage of using a self‐healing mechanism and SiCw reinforcement. Tensile, tribological, and Charpy impact tests were performed to characterize the mechanical and tribological properties, which were supported with microscopic observations. Multiple experimental characterizations were performed to investigate the impact, and the ultimate tensile strength (UTS) and energy absorption capacity of the structure were shown to increase by 32% and 45%, respectively, with the addition of SiCw. The presence of self‐healing agents provides a 5% rise in UTS after enough time for healing following the collision. The structure's tribological performance is improved by 10% in wear resistance and 20% in friction coefficient. Hybrid laminated composite structure with silicon carbide whisker and self‐healing capsules. Tensile and Charpy impact tests conducted with microscopic observations Increased ultimate tensile strength and energy absorption capacity by 32% and 45%. Tribological improvement by 10% in wear resistance and 20% in friction coefficient. [ABSTRACT FROM AUTHOR]

Epoxy asphalt, a thermosetting polymer, is characterized by stable, irreversible internal chemical bonds that prevent recovery and spontaneous micro‐crack healing, unlike conventional asphalt. This study introduces a renewable nano‐modifier synthesized via esterification of carboxyl‐functionalized carbon nanotubes (CNTs‐COOH) and furfuryl alcohol (FA), termed CNTs‐FA. The successful synthesis of CNTs‐FA was confirmed through various microscopic techniques. Integrating CNTs‐FA into epoxy asphalt materials, the optimal dosage was identified as 0.05% of the total epoxy asphalt mass using tensile tests and fluorescence microscopy. Thermal reversible effects and mechanisms were further analyzed through multiple regeneration cycles using tensile properties, fluorescence microscopy, and infrared spectroscopy. The study elucidates that the thermal reversibility in epoxy asphalt is facilitated by the Diels‐Alder (DA) reaction between the conjugated diene structure in FA and the curing agent oleylamine. This research provides an effective solution to the non‐recoverability and unrepairable micro‐cracks of traditional epoxy asphalt mixtures. Highlights: CNTs‐FA was successfully prepared by esterification reaction.Using nano modification methods, introduce DA reaction into curing system.Renewable function of epoxy asphalt by DA reversible reaction. [ABSTRACT FROM AUTHOR]

In order to overcome the commercialized silicone‐based thermal interface materials' issues such as oil leakage and mechanical damage, we developed a thermoset silicone rubber matrix (SR) achieved through the condensation reaction of hydroxyl silicone oil and tetraethyl silicate. Additionally, we constructed a self‐healing and recyclable silicone rubber matrix (SCNR) by incorporating heat reversible ionic and hydrogen bonds between carboxyl and amino functionalized polydimethylsiloxane. Finally, the flexible, low oil leakage, self‐healing, and recyclable composites Al2O3/BN@SR/SCNR was prepared by adjusting the ratio of SR/SCNR and the spherical alumina and boron nitride (BN) fillers. The results indicated that with SR/SCNR mass ratio of 1/0.075 and filler content of 70 wt%, the thermal conductivity of the composite reaches 1.866 W m−1 K−1, 646% increasing over the SR/SCNR matrix. The self‐healing efficiency reaches 97% and the thermal conductivity remains essentially unchanged after being recycled for three times. The composites can be bent and twisted multiple times and still return to their original shape. Notably, the oil leakage of the Al2O3/BN@SR/SCNR composites is significantly lower than that of additive silicone composites. Therefore, the recyclable thermal conductivity composite developed in this study provides a promising solution for improving the durability of heat dissipation materials in electronic devices. [ABSTRACT FROM AUTHOR]

Lithium‐ion cells encompassing LiPF6 as the lithium salt and high‐voltage (LiNi0.5Mn1.5O4, LNMO) or high‐capacity (LiNi0.8Mn0.1Co0.1O2, NMC811) cathode materials are prone to transition metal (TM) dissolution caused by HF, whose formation is catalyzed by H2O traces. TM ions can shuttle to the anodic compartment, increasing the cell degradation rate. Accordingly, specific self‐healing strategies are helpful to develop scavengers able to eliminate HF and absorb TM ions so avoiding their shuttling. In this work, the fabrication and test of a bi‐functional, autonomous scavenging agent made of Al2O3 particles decorated is reported with chitosan. The nanometric Al2O3 core is a trap for HF by chemical bonding. The chitosan coating is acid‐sensitive, and the opening of such a capping layer is triggered in the presence of even small amounts of HF, leading to an efficient TM ion‐trapping. In addition, chitosan is biocompatible, biodegradable, and abundant, which is relevant for design‐for‐recycling scopes. With ≈200 ppm of water in the electrolyte, 12 wt% of scavenger causes, after 200 cycles at 1C, an increase of capacity retention from 73% to 88% for LNMO, and, impressively, from 46% to 84% for NMC811. This autonomous self‐healing mechanism is promising for application in next‐generation smart cells without requiring any external sensing. [ABSTRACT FROM AUTHOR]

Smart persistent organic room‐temperature phosphorescence (RTP) materials, capable of responding to microenvironmental changes, are critically important in various optoelectronic applications. However, conventional persistent RTP materials usually have not stretchability and flexibility, limiting some practical applications. This study reports a facile and one‐pot photo‐initiated copolymerization method to prepare photoactivated persistent RTP polymers with multicolored afterglow, excellent stretchability, self‐healable and recyclable properties. Impressively, the polymers can be stretched up to 500% without significant loss in RTP intensity and lifetime, and they possess a self‐healing ability with a healing efficiency of 69.6%. Utilizing these photoactivated and stretchable persistent RTP polymers, dual encryption can be achieved under UV irradiation and stretching conditions, thereby enhancing the security levels of the stored confidential information. Overall, this study represents the first example of self‐healable and recyclable stimuli‐responsive RTP materials, demonstrating their bright future for the flexible and wearable optoelectronics. [ABSTRACT FROM AUTHOR]

Oral biofilms, including pathogens such as Porphyromonas gingivalis , are involved in the initiation and progression of various periodontal diseases. However, the treatment of these diseases is hindered by the limited efficacy of many antimicrobial materials in removing biofilms under the harsh conditions of the oral cavity. Our objective is to develop a gel-type antimicrobial agent with optimal physicochemical properties, strong tissue adhesion, prolonged antimicrobial activity, and biocompatibility to serve as an adjunctive treatment for periodontal diseases. Phenylboronic acid-conjugated alginate (Alg–PBA) was synthesized using a carbodiimide coupling agent. Alg–PBA was then combined with tannic acid (TA) to create an Alg–PBA/TA hydrogel. The composition of the hydrogel was optimized to enhance its mechanical strength and tissue adhesiveness. Additionally, the hydrogel's self-healing ability, erosion and release profile, biocompatibility, and antimicrobial activity against P. gingivalis were thoroughly characterized. The Alg–PBA/TA hydrogels, with a final concentration of 5 wt% TA, exhibited both mechanical properties comparable to conventional Minocycline gel and strong tissue adhesiveness. In contrast, the Minocycline gel demonstrated negligible tissue adhesion. The Alg–PBA/TA hydrogel also retained its rheological properties under repeated 5 kPa stress owing to its self-healing capability, whereas the Minocycline gel showed irreversible changes in rheology after just one stress cycle. Additionally, Alg–PBA/TA hydrogels displayed a sustained erosion and TA release profile with minimal impact on the surrounding pH. Additionally, the hydrogels exhibited potent antimicrobial activity against P. gingivalis , effectively eliminating its biofilm without compromising the viability of MG-63 cells. The Alg–PBA/TA hydrogel demonstrates an optimal combination of mechanical strength, self-healing ability, tissue adhesiveness, excellent biocompatibility, and sustained antimicrobial activity against P. gingivalis. These attributes make it superior to conventional Minocycline gel. Thus, the Alg–PBA/TA hydrogel is a promising antiseptic candidate for adjunctive treatment of various periodontal diseases. [Display omitted] • Phenylboronic acid-conjugated alginate are synthesized and mixed with tannic acid to form hydrogel (Alg-PBA/TA). • Alg-PBA/TA hydrogel exhibits self-healing property and tissue-adhesiveness. • Alg-PBA/TA hydrogel effectively removes Porphyromonas gingivalis biofilms. • Alg-PBA/TA exhibits no notable cytotoxicity on MG-63 cells. [ABSTRACT FROM AUTHOR]

Stiff structures are generally considered detrimental to the materials' self-healing efficiency because of the rigid conformation and restricted motion of the molecular chains. However, in this study, an unexpected acceleration in self-healing was observed in a urethane network when lignosulfonate, a bio-based stiff structure with stiff benzene rings, was introduced into the polyurethane matrix. An extraordinary increase in mechanical properties was achieved with just 3 wt% lignosulfonate added to the pristine sample, including a strength increase from 16.24 MPa to 42.89 MPa and elongation at break from 390% to 602%. Importantly, this significant enhancement in mechanical properties was accompanied by a notable acceleration in healing time efficiency, which increased by up to 44% compared to the pristine sample. This unique behavior can be attributed to the mediation of lignosulfonate on the ionic bonds between lignosulfonate and the urethane segment, as well as the hydrogen bonds formed within the urethane segments. This mediation ensures ultra-high strength without compromising the self-healing capacity and opens a way for accelerating elastomers self-healing efficiency through lignosulfonate, a readily available biomass-derived material. In addition, the addition of lignosulfonates gives the elastomer some Anti-UV performance. [ABSTRACT FROM AUTHOR]

Crosslinking natural rubber (NR) and styrene butadiene rubber (SBR) composites with carbon black (CB) have been utilized in the tire tread industry. A sulfur-based lightly crosslinker can potentially enhance the self-healing capabilities of rubber. Moreover, the rubber composites were studied for non-covalent interactions between the benzene rings of SBR and CB. In this research, rubber samples were prepared, and their structure was investigated using Fourier transform infrared (FTIR), and Raman spectroscopy. The red shift in Raman spectroscopy confirmed non-covalent interaction or hydrophobic interaction between SBR and CB in NR/SBR composites exposed to CB due to environmental change. The differential scanning calorimetry (DSC) thermograms showed that NR and SBR were incompatible. Additionally, the mechanical properties of these rubber blends were enhanced as the proportion of NR increased. The maximum self-healing performance reached 40% for the formulation containing 25 phr NR and 75 phr SBR, which also saved energy with low chain end movements. Therefore, these composites could be utilized as a semi-empirical model for studying crosslinked rubber blends, specifically in the rubber tire industry. [ABSTRACT FROM AUTHOR]

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 = 595–605 nm. 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 (0–100 vol%) 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%). [ABSTRACT FROM AUTHOR]

In this study, a flexible sensor is successfully fabricated using self‐healing nanocomposite hydrogels for monitoring human movement. The eco‐friendly cellulose nanocrystals (CNCs) are used as nano‐reinforcing materials, and the mechanical properties and self‐healing efficiency of the materials are improved. The self‐healing efficiency of hydrogels are realized by introducing a variety of reversible non‐covalent interactions such as hydrogen bonding, borax chelation, and metal coordination. Notably, the mechanical strength and self‐healing efficiency of these nanocomposite hydrogels can reach 2.8 MPa and 89.9%, respectively. Importantly, these self‐healing nanocomposite hydrogels have been widely used in wearable flexible sensors to achieve high sensitivity to large‐scale human movement. It is of great significance to design functional materials with good biocompatibility, sensitivity, and mechanical strength for wearable sensors. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) plays a critical role in elastomers, adhesives, and self-healing materials. We selected the most commonly used aromatic isocyanates, 4,4′-methylene diphenyl diisocyanate (MDI) and tolylene-2,4-diisocyanate (TDI), and the most commonly used aliphatic isocyanates, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane-4,4′-diisocyanate (HMDI), as raw materials, combined with polytetramethylene ether glycol (PTMG) and 1,4-butanediol (BDO) to successfully synthesize five PU materials. The effects of isocyanate structure on polymerization rate, hydrogen bonding, thermal properties, phase separation, wettability, self-healing performance, adhesion, and mechanical properties were systematically investigated. The results show that isocyanates with higher symmetry facilitate hydrogen bonding, but excessive flexibility and crystallinity may inhibit its formation. MDI-based PU exhibits the highest hydrogen bonding index (HBI) of 4.10, along with the most distinct phase separation and the highest tensile strength of 23.4 MPa. HMDI-based PU demonstrates the best adhesion properties, with the highest lap shear strength of 7.9 MPa, and also exhibits excellent scratch healing ability. IPDI-based PU shows good self-healing performance, recovering 88.7% of its original tensile strength and 90.6% of its original lap shear strength after heating at 80 °C for 24 h. Furthermore, all the samples can be reprocessed by melt or solution methods, showing excellent recyclability. [ABSTRACT FROM AUTHOR]

Here, we report a reprocessible, reusable, self-healing, and form-switching polymeric adsorbent for remediating fluorinated pollutants in water. The copolymer hydrogel is designed to contain fluorophilic segments and cationic segments to induce strong binding with perfluorinated pollutants. The sorption performance reveals rapid and quantitative removal of these pollutants, driven by the synergistic effect of fluorophilic and electrostatic interaction. Importantly, a disulfide-containing dynamic crosslinker plays a crucial role in imparting multifunctionality. This enables self-healing by the restoration of crosslinks at the cut surfaces by disulfide exchange reactions and allows for the repeated use of the adsorbent via multiple adsorption–desorption cycles. Furthermore, the adsorbent is reprocessible by cleaving the crosslinks to afford linear copolymers, which can be repolymerized into a hydrogel network on demand. Also, form-switching capability is showcased through the aqueous self-assembly of linear copolymers into a fluorinated micelle, serving as another form of adsorbent for pollutant removal. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable hydrogen production via water electrolysis, paramount importance of electrocatalyst stability emerges as a defining factor for long‐term industrial viability. A thorough understanding and enhancement of stability not only ensure extended catalyst lifetimes but also pave the way for consistent and efficient hydrogen generation. This review focuses on the pivotal role of stability in determining the practical viability of oxygen evolution electrocatalysts (OECs) for large‐scale applications in water electrolysis for hydrogen production. The paper explores the pivotal role of stability over initial activity, citing examples and hypothetical scenarios. First, figures of merits for stability evaluation of the electrocatalyst are explained along with the available benchmarking protocols for stability evaluation. Further, the text delves into various strategies that can enhance the stability of the electrocatalyst which include self‐healing/regeneration pathway, oxygen evolution reaction (OER) mechanism optimization to achieve highly stable OER and stabilization of active metals atoms within the electrocatalyst to inhibit dissolution as a way forward for industrial application. The interplay of stability, activity, and cost is also explained to suit the industrial application of the electrocatalyst. Lastly, it outlines challenges, prospects, and future directions, presenting a guide for advancing OECs in the hydrogen generation landscape. [ABSTRACT FROM AUTHOR]

In this study, we report the development of a hybrid polymer material comprising poly(butyl methacrylate) and titania, which exhibits the three key elements of visible-light transparency, UV shielding, and self-healing. Nanodispersion of titania in the polymers was achieved using the sol – gel method using titanium propoxide as the raw material. Furthermore, by adding tetrabutylphosphonium chloride, an ionic liquid, we suppressed visible light absorption due to charge transfer between poly(butyl methacrylate) and titania, resulting in enhanced visible light transmittance. An approach involving crosslinking points comprising Diels – Alder functional groups was used to heal scratches in the hybrid material at 75°C for 30 min. Dynamic viscoelastic measurements and microscopic observations were conducted to investigate the self-healing mechanism. These findings suggested that this phenomenon occurred through the fluidization of the polymer matrix and the recombination reaction of the crosslinking points, which comprise Diels – Alder and titania. The development of intelligent materials with combined transparency, UV protection, and self-healing capabilities provides potential avenues for future research to enhance and broaden their versatile characteristics for widespread applications. [ABSTRACT FROM AUTHOR]

This article provides a brief description of microcapsule self-healing technique and its potential use in concrete structures. Because concrete is readily available and reasonably priced, it is widely utilised in the building industry globally, despite its susceptibility to the formation of cracks. The longevity and security of concrete buildings are greatly impacted by the existence of cracks and other deterioration occurring during the course of their use. Through the encapsulation of healing material inside microcapsules, which shows rupture upon cracking in cement-based materials, the microcapsule exhibits promise in accomplishing self-healing and increasing durability and strength in the structures. The article first explains the basic ideas behind the science of microcapsule self-healing and then looks at different ways to prepare microcapsules. It also looks into how adding microcapsules affects the basic characteristics of the concrete building. A summary of the efficiency and self-healing mechanisms of microcapsules is also provided. Highlights: The article explains the advantages of the microcapsule self-healing method in concrete. Preparation method and intrinsic properties of different microcapsules are discussed. Different self-healing measurement techniques in cement-based materials are discussed. The study examines the qualitative aspects of various self-healing methods. Looks into how adding microcapsules affects the properties of cementitious materials. [ABSTRACT FROM AUTHOR]

Recent decades have witnessed the increasing use of soil mixing technology to construct cut-off walls for groundwater control or underground pollutant containment. The strength and permeability of soil mix columns deteriorate considerably when subjected to chemical, mechanical and environmental stresses, leading to the need for repair of crack-originated damage. The development of self-healing grouts could provide more resilient and sustainable soil mix cut-off walls. In this study, for the first time, self-healing soil mix columns incorporating reactive magnesium oxide pellets were developed. The magnesium oxide-based cementitious grout was mixed with a sand soil using a laboratory-scale auger, and the embedded magnesium oxide pellets were ruptured upon cracking, producing expansive healing products due to hydration and carbonation, which can significantly fill the crack volume. The effects of magnesium oxide on the grout and soil mix samples were investigated in terms of both fresh and hardened properties. In addition, the self-healing performance was evaluated by examining permeability recovery and crack closure, and the microstructure and morphology of the magnesium oxide pellets and healing products were analysed. The results demonstrate the great potential of reactive magnesium oxide pellets as a self-healing agent for soil mix cut-off wall materials. [ABSTRACT FROM AUTHOR]

When asphalt pavement is in practical use, it is prone to cracking and other diseases due to the long-term effects of load and climate and the restricted self-healing properties of the asphalt material. In order to improve the properties and durability of asphalt pavement, we introduced disulfide bonds into polyurethane (PU) in this study. We prepared polyurethane-modified asphalt (PUA) containing dynamic disulfide covalent bonds using polytetrahydrofuran (PTMG), polyethylene adipate (PEA), and hydroxyl-terminated polybutadiene (HTPB) as soft segments. Subsequently, the rheological properties, healing performance, and microstructure of the PUA were studied. The results indicated that the PU with disulfide bonds was integrated into the asphalt and had good dispersity. A cross-linked network structure formed between them. PUA with HTPB as the soft segment had excellent high-temperature deformation and low-temperature cracking resistance and a prominent advantage in durability. In comparison, PUA synthesized with PEA had better high-temperature performance and fatigue resistance, and PUA synthesized with PTMG had considerable low-temperature properties and stability. The disulfide bonds had a positive impact on the high-temperature performance, aging resistance, and healing properties of PUA through constant dynamic exchange and topological rearrangement effects. This study provides a reference for the preparation of PUA with ideal self-healing ability and has instructive significance for the selection of soft segment materials for synthesizing PUA. [ABSTRACT FROM AUTHOR]

This research aims to investigate the self-healing of low-temperature cracks in asphalt mixture using semicircular bending tests at different modes of fracture. In this research, samples are fabricated with a 12.5 mm nominal size aggregate and PG58-22 binder. All aged and unaged asphalt samples are subjected to 10 cooling cycles. Also, the resting time between cooling cycles is applied to self-healed samples. The results show that cooling cycles significantly reduce the fracture energy and applying the resting time increases the healing, cracking resistance, and balanced cracking indices. In addition, the most effective of self-healing is observed at fracture mode II. [ABSTRACT FROM AUTHOR]