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.
Biodegradable self-healing hydrogels with antibacterial property attracted growing attentions in biomedication as wound dressings since they can prevent bacterial infection and promote wound healing ...process. In this research, a biodegradable self-healing hydrogel with ROS scavenging performance and enhanced tissue adhesion was fabricated from dopamine grafted oxidized pectin (OPD) and naphthoate hydrazide terminated PEO (PEO NH). At the same time, Fe3+ ions were incorporated to endow the hydrogel with near-infrared (NIR) triggered photothermal property to obtain antibacterial activity. The composite hydrogel showed good hemostasis performance based on mussel inspired tissue adhesion with biocompatibility well preserved. As expected, the composition of FeCl3 improved conductivity and endowed photothermal property to the hydrogel. The in vivo wound repairing experiment revealed the 808 nm NIR light triggered photothermal behavior of the hydrogel reduced the inflammation response and promoted wound repairing rate. As a result, this composite FeCl3/hydrogel shows great potential to be an excellent wound dressing for the treatment of infection prong wounds with NIR triggers.
Hard carbon (HC) anodes have shown extraordinary promise for sodium‐ion batteries, but are limited to their poor initial coulombic efficiency (ICE) and low practical specific capacity due to the ...large amount of defects. These defects with oxygen containing groups cause irreversible sites for Na+ ions. Highly graphited carbon decreases defects, while potentially blocking diffusion paths of Na+ ions. Therefore, molecular‐level control of graphitization of hard carbon with open accessible channels for Na+ ions is key to achieve high‐performance hard carbon. Moreover, it is challenging to design a conventional method to obtain HCs with both high ICE and capacity. Herein, a universal strategy is developed as manganese ions‐assisted catalytic carbonization to precisely tune graphitization degree, eliminate defects, and maintain effective Na+ ions paths. The as‐prepared hard carbon has a high ICE of 92.05% and excellent cycling performance. Simultaneously, a sodium storage mechanism of “adsorption‐intercalation‐pore filling‐sodium cluster formation” is proposed, and a clear description given of the boundaries of the pore structure and the specific dynamic process of pore filling.
Molecular‐level control of graphitization of hard carbon (HC) with open accessible channels for sodium ions by using manganese ions, is a novel strategy to obtain HC with both high capacity and high initial Coulombic efficiency (ICE). The as‐prepared hard carbon exhibits a high ICE of 92.05% and high reversible capacity (336.8 mAh g−1).
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•Injectable hydrogel was prepared combining iota/kappa carrageenan, locust bean gum and gelatin.•The addition of locust bean gum enhanced the mechanical and swelling properties.•The ...incorporation of gelatin improved the cell adhesion and spreading of fibroblasts.•The hydrogel was able to release a growth factor to promote cell migration.•The hydrogel is a good candidate for wound healing and tissue repairing applications.
In this study, a novel injectable hydrogel based on iota and kappa carrageenan, locust bean gum and gelatin was prepared for wound healing and tissue repairing applications. This injectable hydrogel was obtained via physical crosslinking. FTIR analysis confirmed the physical interaction between the biopolymeric components of the hydrogel. The prepared injectable hydrogel exhibited shear-thinning characteristics and could be injected for minimally invasive applications. Also, the hydrogel showed a porous structure, physiological and mechanical stability and biocompatibility. The in vitro cell culture studies showed that fibroblasts were able to grow, adhere and spread inside the hydrogel, indicating that hydrogel could support tissue repair. Moreover, hydrogel could be useful for the delivery of biomolecules. Vascular endothelial growth factor was encapsulated within the hydrogel and subsequently released, which accelerated the migration of human umbilical vein endothelial cells and facilitated in vitro wound healing. Overall, the results indicate that hydrogel can be a potential injectable delivery vehicle for wound healing and tissue repair.
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.
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.
Fabricating injectable hydrogel with multifunctions that matchs the highly ordered healing process of skin regeneration has greatly desired in treatment of chronic diabetic wounds. Herein, a ...pH/reactive oxygen species (ROS) dual responsive injectable glycopeptide hydrogel based on phenylboronic acid-grafted oxidized dextran and caffeic acid-grafted ε-polylysine was constructed, which exhibited inherent antibacterial and antioxidant capacities. The mangiferin (MF) with the ability to promote angiogenesis was encapsulated into pH-responsive micelles (MIC). Subsequently, diclofenac sodium (DS) with anti-inflammatory activities and MIC@MF were embedded into the hydrogel. The hydrogel possessed good biodegradability, stable rheological property and self-healing ability, and could realize the spatiotemporal delivery of DS and MF. The in vitro and in vivo data showed that the hydrogel was biocompatible with effective anti-infection, anti-oxidation and anti-inflammation at early stages, then further promoted angiogenesis and accelerated wound repairing. Collectively, this novel glycopeptide hydrogel provides a facile and effective strategy for chronic diabetic wound repairing.
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•Cracked asphalt models with and without repairing agents were established by MS.•Potential energy is the main driving force of micro crack repair process.•There was a positive correlation between ...temperature and repair action.•Light and long chain-like small molecule is more suitable for a core material.
The objective of this study is to analyze the behavior of repairing agent of microcapsule in asphalt micro crack based on molecular dynamics simulation. Based on the molecular dynamics software Material Studio 7.0 (MS), a four-fraction molecular model of asphalt and a molecular model of repairing agent of the microcapsule core material were constructed. Based on this, the micro crack models with and without repairing agents in asphalt were constructed, and the dynamics simulation calculations were carried out. The density and energy of the repairing agent moving in the micro crack after being released from microcapsule were studied, as well as the diffusion coefficient of molecules of the two models. The shear modulus of the models before and after crack repairing were analyzed. Additionally, the effects of temperature and molecular type on crack repairing were also analyzed. The results indicated that crack repairing was a process of mutual diffusion between the repairing agent and asphalt under the main driving force of potential energy. The repairing agent in the cracks accelerated the diffusion of the asphalt molecules to promote crack repairing rate; Crack repairing speed and temperature were positively correlated, that is, the repair rate increases with the increase of temperature. After the crack repair, the shear modulus of the models with and without repairing agent increased by 228.57% and 111.11%, respectively, indicating that the repairing agent also accelerated the mechanical property recovery of the crack model. The light and long chain-like small molecule type repairing agent could more promote the self-repairing process, and be more suitable for use as a core material repairing agent of microcapsules.
