The development of tin (Sn)‐based perovskite solar cells (PSCs) is hindered by their lower power conversion efficiency and poorer stability compared to the lead‐based ones, which arise from the easy ...oxidation of Sn2+ to Sn4+. Herein, phenylhydrazine hydrochloride (PHCl) is introduced into FASnI3 (FA = NH2CH NH2+) perovskite films to reduce the existing Sn4+ and prevent the further degradation of FASnI3, since PHCl has a reductive hydrazino group and a hydrophobic phenyl group. Consequently, the device achieves a record power conversion efficiency of 11.4% for lead‐free PSCs. Besides, the unencapsulated device displays almost no efficiency reduction in a glove box over 110 days and shows efficiency recovery after being exposed to air, due to a proposed self‐repairing trap state passivation process.
Phenylhydrazine hydrochloride is introduced into FASnI3‐based perovskite solar cells (where FA = NH2CHNH2+) in order to reduce the existing Sn4+ and prevent the further degradation of the FASnI3. Consequently, the champion device shows a high power conversion efficiency up to 11.4%, a long‐term storage stability over 2300 h, and an efficiency recovery capability after being exposed to air.
Superhydrophobic coatings that are also self‐healing have drawn much attention in recent years for improved durability in practical applications. Typically, the release of the self‐healing agents is ...triggered by temperature and moisture change. In this study, UV‐responsive microcapsules are successfully synthesized by Pickering emulsion polymerization using titania (TiO2) and silica (SiO2) nanoparticles as the Pickering agents to fabricate all‐water‐based self‐repairing, superhydrophobic coatings. These coatings are environmentally friendly and can be readily coated on various substrates. Compared to conventional superhydrophobic coatings, these coatings can regenerate superhydrophobicity and self‐cleaning ability under UV light, mimicking the outdoor environment, after they are mechanically damaged or contaminated with organics. They can maintain the superhydrophobicity after multiple cycles of accelerated weathering tests.
An environmentally benign, all‐water‐based self‐repairing superhydrophobic coating based on UV‐responsive microcapsules is fabricated, which exhibits excellent self‐healing and self‐cleaning ability in an outdoor environment, and after mechanical damage and contamination by organics.
The slippery liquid infused porous surface (SLIPS) with excellent anti-corrosion properties have been widely reported in recent years. Unfortunately, most of the previously reported SLIPS struggles ...to provide long-term effective corrosion protection for magnesium (Mg) alloys owing to the lack of effective mesoporous structure self-repairing capability. Herein, a SLIPS with a self-repair microstructure and slippery attributes was fabricated, which consisted of a MnOOH layer and a superhydrophobic active carbon/hydroxyl-modified hexagonal boron nitride (AC/BNO) coating. The abundant mesoporous structure of the AC favors the formation of a dense lubricant layer on the SLIPS. The addition of BNO as a two-dimensional filler creates a “labyrinth effect” within SLIPS, which enhances its overall corrosion resistance. In addition, MnOOH offers a self-repair microstructure and slippery attribute ability for SLIPS. Once the SLIPS is damaged, the damaged area undergoes structural and slippery attributes repair through the spontaneous reaction of MnOOH with Mg2+ and OH− to form Mn-Mg layered double hydroxides (LDH) with mesoporous structure for restoration. Moreover, the SLIPS not only exhibited excellent mechanical stability and anti-contamination performance, but electrochemical experiments also indicated that the corrosion protection efficiency of both the original and self-repaired SLIPS was greater than 99 %, demonstrating excellent corrosion resistance. Therefore, compared with traditional SLIPS, this study not only utilizes AC as storage container to avoid the complex mesoporous structure preparation process but also provides new insights for the sustainable development of SLIPS by regenerating new mesoporous structures and restoring the slippery attributes.
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The generation and expansion of cracks in concrete materials have always been a problem that needs to be solved, and an increasing number of scholars are beginning to hope that structures will have ...bionic functions of self-diagnosis and self-repairing of damage. In this study, shape memory alloy (SMA) concrete beams are prepared. The flexural and self-repairing properties of SMA concrete beams were investigated by a four-point bending test. The effects of various factors on the bearing capacity, ductility, and crack width before and after repair were analyzed. The experimental results indicate that the increase of SMA fiber content and the complexity of the SMA bar end shape can significantly enhance the flexural bearing capacity and repair performance of the beam. The increase in the bond length of SMA bars can enhance the bending resistance of the beam, but it will reduce its self-repairing performance. The repair rate of SMA on concrete cracks is 45.7 %-76.5 %, and the load recovery rate is between 49.4 % and 80.6 %. The flexural load capacity calculation formula is proposed, and the calculation results closely match the test values, providing a reference for the application of SMA.
•The mechanism of SMA fiber on the flexural and repair function was explored.•The effects of the end shape on flexural and self-repairing properties were studied.•The results are analyzed by using grey correlation degree and response surface.•The calculation formula of flexural bearing capacity is proposed.
As a critical part of flexible electronics, flexible circuits inevitably work in a dynamic state, which causes electrical deterioration of brittle conductive materials (i.e., Cu, Ag, ITO). Recently, ...gallium‐based liquid metal particles (LMPs) with electrical stability and self‐repairing have been studied to replace brittle materials owing to their low modulus and excellent conductivity. However, LMP‐coated Ga2O3 needs to activate by external sintering, which makes it more complicated to fabricate and gives it a larger short‐circuit risk. Core–shell structural particles (Ag@LMPs) that exhibit excellent initial conductivity(8.0 Ω sq−1) without extra sintering are successfully prepared by coating nanosilver on the surface of LMPs through in situ chemical reduction. The critical stress at which rigid Ag shells rupture can be controlled by adjusting the Ag shell thickness so that LM cores with low moduli can release, achieving real‐time self‐repairing (within 200 ms) under external destruction. Furthermore, a flexible circuit utilizing Ag@LMPs is fabricated by screen printing, and exhibits outstanding stability and durability (R/R0 < 1.65 after 10 000 bending cycles in a radius of 0.5 mm) because of the functional core–shell structure. The self‐repairable Ag@LMPs prepared in this study are a candidate filler for flexible circuit design through multiple processing methods.
A novel core–shell conductive particle based on liquid metal (Ag@LMPs) is developed. This particle exhibits excellent conductivity without external sintering, while simultaneously exhibiting long‐term durability and real‐time self‐repairing in flexible circuits owing to the release of the liquid metal core. These Ag@LMPs are a candidate filler for self‐repairing flexible circuit design.
Polymer brushes have proven to have great potential in oil-water separation but it remains a long-standing challenge to improve their operational stability and service endurance. In this work, we ...sequentially grafted polydimethylsiloxane (PDMS) and poly (N-isopropylacrylamide) (PNIPAM) brushes on the cotton fabric to prepare a durable and self-reparing oil-water separation film (Co@PDMS/PNIPAM). The grafting of liquid PDMS brushes significantly improved the antifouling performance through its lubricating effect thereby improving the durability. The hydrophilic and thermoresponsive PNIPAM was synthesized through a surface-initiated atom transfer radical polymerization (SI-ARGET ATRP). Co@PDMS/PNIPAM shows high flux in various oily water and bio-solution. More remarkably, Co@PDMS/PNIPAM exhibited intelligent self-repairing characteristics, and this further enhances its stability and service endurance in the application of oil-water separation. The results provide pathways to the preparation of antifouling and durable membranes in the application of water treatment, and resource recovery.
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•Preparation of antifouling and self-repairing cotton fabric with block polymer brush of PDMS/PNIPAM.•Lower PDMS brush enhances the anti-fouling property through its high chain flexibility and low surface energy.•Upper PNIPAM brush improves the wettability and provides a thermal responsiveness.•Co@PDMS/PNIPAMT is a functional and durable oil-water separation membrane, which is applicable in various oily water.
Constructing self‐repairing epoxy materials based on transesterification chemistry can be regarded as a potential path for practical industrial applications given on its simplicity and ease of ...processing. However, there is still a challenge to improve the slow bonding exchange process for desired healing performances. Herein, this work reports a simple and effective strategy to prepare high‐biomass‐content self‐repairing epoxy materials by introducing polyester oligomer (PEO) dicarboxylic acid as modifier into epoxidized soybean oil and itaconic acid compounds. The PEO is synthesized from glutaric anhydride and 1,4‐cyclohexanediol, as well possess a unique pentamer molecular structure. It not only endows the epoxy system with improved molecular mobility in virtue of its long‐chain structure, but also increases the number the essential ester groups of transesterification process, thus synergistically promoting bonding exchange rate for expected properties. As a result, the employment of PEO decreases the activation energy from 100 to 70 KJ/mol, as well as presents optimized self‐repairing efficiency in storage modulus and tensile strength tests compared to the control group. It may provide a new and practical way to fabricate high‐effective self‐repairing epoxy system for industrial applications.
Description of preparation of bio‐based epoxy system with desired self‐repairing performance, and the mechanism for improved self‐repairing properties.
In this study, we present a facile method to prepare photothermal slippery surfaces that exhibit rapid self-repairing, exceptional anti-icing/deicing performance, and excellent stability by combining ...porous substrate, photothermal conversion material, and solid lubricant. This work provides new insights into preparing stable slippery surfaces with both rapid self-repairing ability and excellent stability for practical applications in scenarios requiring anti-icing/deicing properties.
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•PSS could rapidly self-repair under 1 sun or under near-infrared illumination.•Ice did not form on PSS even at –12 ± 1.0 ℃ under 1 sun illumination.•The accumulated ice could melt on PSS within 270.6 ± 2.8 s under 1 sun.•PSS exhibited outstanding stability in air and water.
Ice formation and accretion cause significant economic losses and disastrous events. Designing a new generation of anti-icing/deicing surface has emerged as an effective strategy for anti-icing/deicing. However, fabricating novel anti-icing/deicing surfaces that offer both stability and self-repairing remains a significant challenge. In this study, photothermal slippery surfaces (PSSs) showing rapid self-repairing, exceptional anti-icing/deicing performance, and excellent stability were prepared by combining porous substrate, photothermal material, and solid lubricant. The fabricated surface could rapidly self-repair under 1 sun or under near-infrared (NIR) illumination. Significantly, ice did not form on PSS even at –12 ± 1.0 ℃ under 1 sun. In addition, PSS exhibited rapid photothermal deicing, melting the accumulated ice within 270.6 ± 2.8 s under 1 sun at –12 ± 1.0 ℃. Furthermore, PSS exhibited outstanding stability in air and water for 32 d. This photothermal slippery surface offers significant potential for practical applications that require long-term anti-icing/deicing properties.
Self‐repairing coatings have received widespread attention due to their ability to repair damaged surfaces. However, film‐forming molecules can only be fixed on the metal surface through relatively ...weak physical and chemical adsorption. This drawback limits its self‐repairing ability. Here, a mode‐switchable TENG (MS‐TENG) is developed, which has the ability to switch between AC and DC outputs as an adjustable charge source for self‐repairing coatings. Besides the normal sector electrodes of rotational TENG, MS‐TENG has a special design of external electrodes (small extension electrodes on rotator and inner/outer orbit electrodes on stator) and achieves charge accumulation through an excitation circuit and DC output through air breakdown on external electrodes with advantage of the complete release of accumulated charges. Compared with traditional air breakdown TENG, its current output has been improved. In addition, the air breakdown process occurs in the external electrode framework independent of the TENG body. Therefore, the negative impact of air breakdown is suppressed. Finally, MS‐TENG is used to achieve rapid electrostatic adsorption of charged film‐forming molecules through charge injection. MS‐TENG as a charge source effectively improves the performance of self‐repairing coatings, with a corrosion inhibition rate of 96.9%.
Here, a mode‐switchable TENG (MS‐TENG) is developed that can switch between AC and DC outputs as an adjustable charge source for self‐repairing coatings. Furthermore, MS‐TENG is used to achieve rapid electrostatic adsorption of charged film‐forming molecules through charge injection. MS‐TENG, as a charge source, effectively improves the performance of self‐repairing coatings, with a corrosion inhibition rate of 96.9%.
Infrared transmitting materials (IRTMs) are prone to mechanical and corrosion damage during long‐time exposure to harsh outside environments. However, conventional IRTMs frequently lack ...self‐repairability that limit their lifespan. To address the limitation, thioctic acid‐based epoxy resins (TAEs) are developed from natural thioctic acid and commercial epoxy monomers. The double ring‐opening polymerization (ROP) reactions of thioctic acid and epoxy groups result in dual dynamic covalent bonds with varying bond energies containing relatively weak disulfide bonds and strong ester bonds. As compared with conventional covalent adaptable networks (CANs) that present rapid creep properties when heated, TAEs maintain their geometric stability during rapid self‐repairing at a mild temperature of 80 °C by enhancing network integrity through stable ester crosslinking points. The feature renders TAEs self‐repairing capability while maintaining precise geometrical dimensions, which is suitable for infrared transmitting devices. On the other hand, TAEs exhibit high near‐infrared transmittance (>80%). Therefore, TAEs with self‐repairability and high infrared transmittance demonstrate they can be used as superior polymeric IRTM.
Covalent adaptable networks with dual dynamic covalent bonds, termed thioctic acid‐based epoxy resins (TAEs), are developed. Among TAEs, the relatively weak disulfide bonds provide self‐healing properties and the strong β‐hydroxyester bonds endow TAEs with geometric stability. Combined with their tunable mechanical properties, minimal curing shrinkage, and robust chemical stability, TAEs show great potential for application in infrared‐transmitting polymeric materials.
