Silicon monoxide (SiO) is highly attractive as an anode material for high-energy lithium-ion batteries (LIBs) due to its significantly higher specific capacity. However, its practical application is hindered by substantial volume expansion during cycling, which leads to material pulverization and an unstable solid electrolyte interphase (SEI) layer. Inspired by the natural root fixation in soil, we designed a root-like topological structure binder, cassava starch-citric acid (CS-CA), based on the synergistic action of covalent and hydrogen bonds. The abundant -OH and -COOH groups in CS-CA molecules effectively form hydrogen bonds with the -OH groups on the SiO surface, significantly enhancing the interfacial interaction between CS-CA and SiO. The root-like topological structure of CS-CA with a high tolerance alleviates the mechanical stress generated by the volume changes of SiO. More encouragingly, the hydrogen bond action among CS-CA molecules produces a self-healing effect, which is advantageous for repairing damaged electrodes and preserving their structural integrity. As such, the CS-CA/SiO electrode exhibits exceptional cycling performance (963.1 mA h g-1 after 400 cycles at 2 A g-1 ) and rate capability (558.9 mA h g-1 at 5 A g-1 ). This innovative, topologically interconnected, root-inspired binder will greatly advance the practical application of long-lasting micron-sized SiO anodes. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

This research explores the innovative resilience and self-healing properties of engineered cementitious composites (ECC) reinforced with shape memory alloy (SMA) fibers, tailored for environments susceptible to saltinduced freeze-thaw damage from deicing salts, seawater, and saline soils. The study examines ECC composites enhanced with varying SMA fiber volumes 0 %, 0.5 %, 0.75 %, and 1 % and three fiber shapes linear, indented, and hook-shaped, with an additional sandblasting surface treatment. Systematic analyses of monotonic and cyclic flexural behavior, as well as self-healing efficacy, were performed across four distinct freeze-thaw cycles (0, 50, 100, and 150) within environments of fresh water and a 3.5 % NaCl solution. Digital Image Correlation (DIC) was employed to precisely monitor the self-healing performance. The results highlight substantial enhancements in SMA-ECC, particularly improved flexural strength by up to 35 %, 30 %, and 17 % for hook, indented, and linear fibers respectively in freshwater. These gains were slightly reduced under saltwater conditions to 32 %, 26 %, and 15 % respectively. Additionally, crack-closure efficiencies in significant self-healing with improvements of 45 %, 38 %, and 27 % for hook, indented, and linear fibers respectively. The Weibull probability distribution model was used to establish the damage evolution equation of the SMA-ECC in two freeze-thaw environments. The results of this study can serve as a reference for the development of freeze-thawresistant designs for SMA-ECC structures in future applications.

Most self-healing rubber composites are produced through hydrogen or ionic bonding. In this study, high-strength self-healing composites were prepared by using guar gum (GG) powder as a filler. The fundamental properties of GG were analyzed using various techniques, including scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis, before its use. After incorporating GG into epoxidized natural rubber (ENR), various properties of the rubber composites, including mechanical strength, self-healing efficiency, and biodegradability, were evaluated at different GG concentrations. The results revealed that GG has a structure similar to polysaccharides, containing hydroxy functional groups in its chemical structure. As GG was added to ENR, both hardness and tensile strength increased, with the maximum tensile strength of similar to 1.03 N/mm(2) (approximately 91.3% increase) observed at 3 parts per hundred rubber (phr) of GG. Notably, self-healing efficiency improved with increasing GG content up to 1 phr (approximately an 81.8% increase), after which it began to decrease. In biodegradability tests, the ENR/GG composites exhibited significant degradation over a 360-day soil burial period, with the formulation containing 5 phr of GG showing the highest weight loss (approximately 40.4%). The rubber composites with good self-healing and mechanical properties could have potential applications in various fields, including medical devices and food packaging. Moreover, the unique properties of the composite could be adapted for use in smart materials or flexible electronics, where self-healing and biodegradability can extend device lifetimes and reduce waste.

The effects of two different bacteria species on the strength, durability, and microstructure of self-healing concrete were compared. A new wild-type calcifying strain, extracted from agricultural soil of Gilan province, Iran, was used to prepare bacterial concrete. This strain was identified as Bacillus licheniformis. The self-healing capacity of this bacteria was evaluated at three different cell concentrations (1.5 x 10(8), 3.0 x 10(8), and 6.0 x 10(8 )cells/ml), and its performance was compared with a standard strain of Sporosarcina pasteurii, which was prepared from the Iranian culture collection. Expanded perlite aggregate was used as a carrier. The mechanical properties and durability of mixtures at 7, 28, and 90 days were tested. The microstructure of some mixtures was also analyzed using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction. The results indicated that the strength and permeability of the concrete were improved with the addition of bacteria. The mixture with 6 x 10(8 )cells/ml B. licheniformis showed, respectively, 22% and 38% increases in compressive and tensile strength at 28 days. The FESEM and EDS results showed that the precipitation of calcite in concrete containing wild-type B. licheniformis was higher than that of the concrete containing S. pasteurii.

This study comprehensively investigates the literature on using bacteria to confer self-repair abilities on concrete and mortar. Although crack-healing is the main objective, calcite-precipitating bacteria affect concrete's durability and mechanical properties. This article reviews the research on bacteria-based self-healing concrete and its developments from 1984 to 2023. This systematic review was developed by adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. R studio and Vosviewer were used to perform bibliometric analysis and visualization of the 295 documents by 874 authors affiliated with 97 sources acquired from Scopus (NY). It is vital to emphasise that the document selection was carried out by two impartial reviewers to prevent any bias. In addition to repairing cracks in the material, the data indicate that applying various self-healing bacteria improves concrete's mechanical and durability properties. A meta-analysis evaluated the summary effect size of the most cited articles. It was concluded with the statistical evidence from the meta-analysis that bacteria incorporated concrete, which shows self-healing efficiency of 5.07 and 7.29 times than that of control concrete.

This paper assesses the performance of biopolymers (agar gum and guar gum) for soil stabilization and the self-healing properties of these materials using non-destructive ultrasonic pulse velocity (UPV) and unconfined compressive strength (UCS) tests. Scanning electron microscopy (SEM) tests were performed to investigate the microstructure of the stabilized soil during the self-healing process. The results showed that adding biopolymers to the soil significantly improved the soil's mechanical properties and self-healing properties. The self-healing indexes of sandy soil stabilized with 1% of guar gum and agar gum were 45% and 18%, respectively, at the curing time of 14 days. Increasing the internal bonds and reducing cracking caused by hydrogel swelling are the significant advantages of using biopolymers in soil stabilization. The UPV provides a quick and accurate estimate of changes in the properties of the stabilized soil. The UPV of the samples increased after the self-healing period. The UPV of the sandy soil stabilized with 1% guar gum and agar gum increased by 17% and 13%, respectively, at the curing time of 7 days. The SEM results showed that the swelling of biopolymers led to crack repair after the self-healing period, the creation of new bonds between grains, and the increase of the contact surface of soil particles.

The cracks in concrete serve as pathways for aggressive agents, leading to deterioration. One approach to addressing these cracks and enhancing structures durability is the use of self-healing agents, such as bacteria used to heal cracks in cementitious matrices. Bacteria can be found in several environments, and their identification and healing viability must be evaluated prior to their use in cementitious matrices. In this study, distinct indigenous bacteria were collected from soil in industrial yards associated with the cement industry. These bacteria were identified and incorporated in cement and mortar mixtures with 18% entrained air. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed to characterize the formed products, and compressive strength testing was conducted to evaluate the mechanical properties of the mortars. The identified bacteria were of the genus Cronobacter, Citrobacter, Bacillus, and Pseudomonas, and their potential to form self-healing products was evaluated with microscopic and mineral analyses. Results showed that all bacteria could form calcite (CaCO3) crystals, with full crack healing in some of the samples. Mechanical testing indicated increases in average compressive strength of up to 108% at 28 days with respect to a reference mortar.

This study provides novel insights into enhancing the self-healing capacity of cement matrix through the integration of natural Bacillus isolates derived from leached and calcified soils. The challenging and highly alkaline environment of cement matrix typically impedes bacterial activity, making the successful application of these bacteria in such conditions particularly significant. In this research, Bacillus licheniformis-Bacillus muralis co-culture was identified as highly effective in inducing calcium carbonate precipitation, a critical factor for self-healing. The selected co-cultured bacterial activity resulted in the formation of up to 2.885 g/100 mL of CaCO3, while the co-culture's effectiveness was demonstrated by the complete repair of a 0.5 mm crack within 96 h demonstrating a repair rate of approximately 0.125 mm per 24 h. Furthermore, the study showed that the bacterial co-culture could survive and remain active under varying environmental conditions, including wet-dry cycles and extreme pH levels, which are typical of construction sites. This rapid crack closure, achieved without additional protective measures for the bacteria, marks a significant advancement in the application of microbial co-cultures for enhancing the durability of cement-based materials. The study also provides a detailed analysis of bacterial behavior under various environmental stresses typical of construction sites, highlighting the robustness and practical applicability of this biotechnological approach. As the long-term output, the obtained results represent a substantial advancement in the practical application of microbial co-cultures for self-healing effect of cement-based materials.

This study investigates a neoteric approach in manufacturing lunar regolith-filled shape memory vitrimer (SMV) composites for extraterrestrial applications. A SMV with robust mechanical properties was combined with locally available lunar regolith to form a composite material. Fourier Transfer Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA), and X-ray fluorescence (XRF) were used to characterize the resin, the regolith simulant, and the prepared SMV-regolith composites. We explored conventional synthesis as well as 3D printing methods for manufacturing the composite. Glass fabric-reinforced laminated composites were also prepared to evaluate the impact tolerance and damage healing efficiency. Compressive strength, flexural strength, and impact resistance of the composite were tested at both room and elevated temperatures. A compressive strength of 96.0 MPa and 5.4 MPa were recorded for composite with 40 wt% regolith ratio at room and elevated temperatures, respectively. The glass fabric reinforced SMV-regolith laminate exhibited a bending strength of 232.7 MPa, good impact tolerance under low-velocity impact test, and good healing efficiency up to two damage healing cycles. The 3D printed SMV-regolith composite using a liquid crystal display (LCD)-based printer exhibited a good thermomechanical property with a compressive and tensile strength of 139.16 MPa and 13.99 MPa, respectively, and a good shape memory effect. However, the LCD-based printing using vat-photopolymerization limits the size of the printed samples. Nonetheless, this study shows that utilization of regolith to form advanced composite is possible. SMV regolith composite is a promising material for lunar base applications due to its simple manufacturing process, excellent mechanical properties, and low energy consumption.

The causes of ground fissure formation are closely related to the change in the stress state in a loose layer, but many researchers often ignore the dynamic processes of mining when studying mining-induced damage mechanisms. The study of stress evolution in a loose layer during mining can help to reveal the causes of surface damage and its self-healing mechanism. This paper establishes a numerical model to study a loose layer's stress evolution and its causes during mining. The discriminative conditions of the potential dynamic fissure formation cycles and self-healing are given. The vertical and horizontal stresses in the loose layer at the mining boundary increase and then decrease under the mining disturbance, and the vertical stresses in the loose layer above the comprehensive mining surface undergo two increasing and decreasing stages, while the horizontal stresses increase and decrease and then increase again. The permanent fissures at the mining boundary form because of the decompression- and compression-related damage caused by horizontal unloading, while the dynamic fissures in the loose layer at the mining surface form due to the first horizontal unloading effect; the shear damage is caused by the second increase in vertical stress. Additionally, the soil Mohr-Coulomb strength criterion and the linear elastic stress-strain relationship are used to discriminate the single- and double-cycle development patterns of the dynamic fissures on the ground surface.