Self-Adapting and Self-Healing Hydrogel Interface with Fast Zn2+ Transport Kinetics for Highly Reversible Zn Anodes

Construction of polymer-based artificial solid-electrolyte interphase films on Zn metal anode holds great potential in the suppression of both dendrite growth and side reaction in rechargeable aqueous Zn-ion batteries. However, the traditional polymer films suffer from the critical issues of sluggish Zn²⁺ transport kinetics and rigid interface. Herein, zinc alginate (ZA) hydrogel is designed and prepared as a dynamic interface and Zn²⁺ redistributor on Zn anode via in situ cross-linking reaction. The zincophilic and negatively charged carboxyl groups of ZA promote the transport of Zn²⁺ ions along a “Z-type” pathway, the repulsion of free SO₄^2- anions, and the desolvation of Zn²⁺ ions, consequently leading to the homogeneous deposition of Zn and the effective suppression of side reaction. Additionally, the dynamic flexibility of ZA hydrogel endows the Zn anode with self-adapting interface to accommodate the volume variation and repair the possible ruptures, thereby guaranteeing the long-term cycling stability. Assisted by the ZA layer, the Zn anode achieves a prolonged lifespan over 2200 h without the formation of Zn dendrites and by-products. Outstanding cycling stability is also demonstrated for the Zn anode when coupled with MnO₂ cathode, further demonstrating its prospects for practical application.     

Ionic Thermoelectric Properties of Reconstructed Lamellar Vanadium Pentoxide Membranes

In recent years, the application of ionic thermoelectric (TE) materials to convert low-grade waste heat into electricity has become a subject of intense scientific research. However, most of the efforts are focused on organic polyelectrolytes or ionic-liquids embedded in polymeric gels. Here, for the first time, it is demonstrated that nanofluidic membranes of reconstructed layered materials like vanadium pentoxide (V₂O₅) exhibit excellent ionic-TE characteristics. The high Seebeck coefficient (S = 14.5 ± 0.5 mV K^-1) of the V₂O₅ membrane (VO-M) is attributed to temperature gradient-induced unidirectional transport of protons through the percolated network of 2D nanofluidic channels. The TE characteristics of VO-M show nearly 80% improvement (S = 26.3 ± 0.7 mV K^-1) upon functionalizing its percolated network with ionic polymers like poly(4-styrenesulfonic acid) (PSS). Further, unlike organic polymer-based TE systems, VO-M not only sustains exposure to high temperatures (≈200 °C, 5 min) but also protects the PSS molecules intercalated into its interlayer space. Moreover, V₂O₅-based TE materials can self-repair any damage to their physical structure with the help of a tiny water droplet. Thus, nanofluidic membranes of reconstructed layered materials like VO-Ms demonstrate vast robustness and great ionic-TE performance, which can provide a novel platform for scientific studies and futuristic applications.     

Injectable,Micellar Chitosan Self-Healing Hydrogel for Asynchronous Dual-Drug Delivery to Treat Stroke Rats

Stroke is a common disease with high mortality worldwide. The endogenous neural regeneration during the intracerebral hemorrhage (ICH) stroke is restricted by the brain cavity, inflammation, cell apoptosis, and neural scar formation. Biomaterials serving as temporary supporting matrices are highly demanded as injectable implants for brain tissue regeneration. Herein, a chitosan micellar self-healing hydrogel (CM hydrogel) with comparable modulus (≈150 Pa) to brain, shape adaptability, and proper swelling (≈105%) is developed from phenolic chitosan (PC) and a micellar crosslinker (DPF). Two model drugs are individually packaged in the hydrophilic network and hydrophobic micelle cavities of CM hydrogel, and they feature asynchronous releasing kinetics, including a first-order rapid release for hydrophilic drug and a zero-order sustained release for hydrophobic drug. The dual-drug loaded CM (CMD) hydrogel delivers two clinical drugs corresponding to the anti-inflammatory and neurogenesis phases of the stroke to ICH rats through brain injection. The rats receiving CMD hydrogel show behavioral improvement (≈84% recovery) and balanced brain midline shift (≈0.98 left/right hemibrain ratio). Immunohistochemistry reveals neurogenesis (doublecortin- and nestin- positive cells) and evidence of angiogenesis (≈18 µm diameter vessels lined with CD31-positive cells). The injectable CMD hydrogel offers a novel asynchronous drug delivery platform for treating ICH stroke.     

Cyclodextrin Nano-Assemblies Enabled Robust,Highly Stretchable,and Healable Elastomers with Dynamic Physical Network

Artificial materials with biomimic self-healing ability are fascinating, however, the balance between mechanical properties and self-healing performance is always a challenge. Here, a robust, highly stretchable self-healing elastomer with dynamic reversible multi-networks based on polyurethane matrix and cyclodextrin-assembled nanosheets is proposed. The introduction of cyclodextrin nano-assemblies with abundant surface hydroxyl groups not only forms multiple interfacial hydrogen bonding but also enables a strain-induced reversible crystalline physical network owing to the special nanoconfined effect. The formation and dissociation of a dynamic crystalline physical network under stretching–releasing cycles skillfully balance the contradiction between mechanical robustness and self-healing ability. The resulting nanocomposites exhibit ultra-robust tensile strength (40.5 MPa), super toughness (274.7 MJ m⁻³), high stretchability (1696%), and desired healing efficiency (95.5%), which can lift a weight ≈ 100 000 times their own weight. This study provides a new approach to the development of mechanically robust self-healing materials for engineering applications such as artificial muscles and healable robots.     

Functional Liquid Crystal Elastomers Based on Dynamic Covalent Chemistry

The marriage of liquid crystal elastomers with dynamic covalent chemistry can be a new paradigm for the development of dynamic and intelligent polymers with versatile functionalities, which is of paramount significance for many emerging applications such as adaptive optics, soft robotics, bioinspired camouflage, 3D/4D printing technology and beyond. Read more in the Review by Wang, Feng et al. ( 10.1002/chem.202201957 )     

Developing a Self‐Healing Supramolecular Nucleoside Hydrogel Based on Guanosine and Isoguanosine

Recently, supramolecular hydrogels have attracted increasing interest owing to their tunable stability and inherent biocompatibility. However, only few studies have been reported in the literature on self‐healing supramolecular nucleoside hydrogels, compared to self‐healing polymer hydrogels. In this work, we successfully developed a self‐healing supramolecular nucleoside hydrogel obtained by simply mixing equimolar amounts of guanosine (G) and isoguanosine (isoG) in the presence of K⁺. The gelation properties have been studied systematically by comparing different alkali metal ions as well as mixtures with different ratios of G and isoG. To this end, rheological and phase diagram experiments demonstrated that the co‐gel not only possessed good self‐healing properties and short recovery time (only 20 seconds) but also could be formed at very low concentrations of K⁺. Furthermore, nuclear magnetic resonance (NMR), powder X‐ray diffraction (PXRD), and circular dichroism (CD) spectroscopy suggested that possible G₂isoG₂‐quartet structures occurred in this self‐healing supramolecular nucleoside hydrogel. This co‐gel, to some extent, addressed the problem of isoguanosine gels for the applications in vivo, which showed the potential to be a new type of drug delivery system for biomedical applications in the future.     

A Rapidly and Highly Self-Healing Poly(Sulfobetaine Methacrylate) Hydrogel with Stretching Properties,Adhesive Properties,and Biocompatibility

This study focuses on the preparation of stretchable zwitterionic poly(sulfobetaine methacrylate) (PSBMA) hydrogels. To address the weak mechanical properties of chemically crosslinked PSBMA hydrogels, a physical crosslinking method utilizing hydrophobic interactions to crosslink hydrogels to approach tough properties is developed. Here, sodium dodecyl sulfate (SDS)-based micelle is used as a physical crosslinker to prepare physically crosslinked PSBMA (PSBMA_phy) hydrogels, and ethylene glycol dimethylacrylate (EGDMA) is used to prepare a control group of chemically crosslinked PSBMA (PSBMA_chem) hydrogels. The mechanical properties of the two hydrogels are compared, and PSBMA_phy hydrogels exhibit greater flexibility than the PSBMA_chem hydrogels. When the PSBMA_phy hydrogels are subjected to external forces, the micelles act as dynamic crosslinking sites, allowing the stress to disperse and prevent the hydrogel from breaking. In addition, the PSBMA_phy hydrogels have nearly 100% self-healing properties within 2.5 min. The PSBMA_phy hydrogels exhibit usable adhesive properties to porcine skin and subcutis. MTT and hemolysis tests show that the PSBMA_phy hydrogels have excellent biocompatibility and hemocompatibility. This study proposes that the multifunctional PSBMA_phy hydrogels with micelles will be potential to carry drugs for use in drug delivery systems in the future.     

Toward Highly Matching the Dura Mater: A Polyurethane Integrating Biocompatible,Leak-Proof,and Self-Healing Properties

The dura mater is the final barrier against cerebrospinal fluid leakage and plays a crucial role in protecting and supporting the brain and spinal cord. Head trauma, tumor resection and other traumas damage it, requiring artificial dura mater for repair.  However, surgical tears are often unavoidable. To address these issues, the ideal artificial dura mater should have biocompatibility, anti-leakage, and self-healing properties. Herein, this work has used biocompatible polycaprolactone diol as the soft segment and introduced dynamic disulfide bonds into the hard segment, achieving a multifunctional polyurethane (LSPU-2), which integrated the above mentioned properties required in surgery. In particular, LSPU-2 matches the mechanical properties of the dura mater and the biocompatibility tests with neuronal cells demonstrate extremely low cytotoxicity and do not cause any negative skin lesions. In addition, the anti-leakage properties of the LSPU-2 are confirmed by the water permeability tester and the 900 mm H₂O static pressure test with artificial cerebrospinal fluid. Due to the disulfide bond exchange and molecular chain mobility, LSPU-2 could be completely self-healed within 115 min at human body temperature. Thus, LSPU-2 comprises one of the most promising potential artificial dura materials, which is essential for the advancement of artificial dura mater and brain surgery.     

基于多Agent免疫算法的智能配电网自愈技术研究

未来智能电网的显著特点是其良好的互动性以及完备的自愈能力,体现了整个电网的技术水平及智能化程度,侧面反映了国家电力系统的发展状况。而智能配电网却是未来智能电网的核心部分,它与用户进行直接的双向互动,这其中涉及到大量分布式电源的接入问题,完备的自愈能力则体现在配电网故障恢复的这一重要环节,是一个多目标、多时段、多维度的非线性的组态优化问题,关系到对用户的供电质量。多Agent技术在计算机网络自愈方面具有得天独厚的优势,国内外学者对此做了大量研究。本文将多Agent免疫算法引入到智能配电网自愈系统的研究中,作为配电网人工智能的故障恢复策略,搭建了基于多Agent免疫算法的配电网自愈架构,并通过仿真平台上的实验证明了将多Agent免疫算法应用到未来智能配电网自愈系统中的可行性。     

The Potential of Microencapsulated Self-healing Materials for Microcracks Recovery in Self-healing Composite Systems: A Review

The autonomic self-healing materials based on microcapsules have made major advancements for the repairing of microcracks in polymers and polymer composite systems. Self-healing encapsulated materials have the inborn ability to heal polymeric composites after being damaged by chemical and mechanical progressions. These intelligent micro-encapsulated self-healing materials possess great capabilities for recovering the mechanical as well aesthetic properties and barrier properties of the polymeric structures. Based on real world observations and experimental data, it is believed that microcracks and microcracking in polymeric materials can result because of many chemical and physical routes and is one of the foremost critical issues for polymeric materials. Especially in polymeric coatings, these microcracks can lead towards disastrous failure, and conventional healing systems like patching and welding cannot be used to repair microcracks at such a micro-level. Self-healing materials, especially, capsule based self-healing materials is a new field sought as an alternative to the conventional repairing techniques, requiring no manual intrusion and uncovering. This review covers the basic and major aspects of the microencapsulated self-healing approach like the effect of synthesis parameters on the size of microcapsules, healing efficiency determination, and the potential of the existing developed microencapsulated agents.