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Periarticular injury usually causes the defects of superficial cartilage and the underlying subchondral bone. Although some efficacious outcomes have been achieved by the existing therapeutic methods both in clinics and research, like symptomatic treatment, microfracture surgery, and tissue engineering technology, they still present specific disadvantages and complications. To improve this situation, we designed a biphasic (bi-) scaffold aiming to repair the structure of cartilage and subchondral bone synchronously. The scaffold consisted of a superior double-network (DN) hydrogel layer and a lower bioactive glass (BG) reinforced hydrogel layer, and the DN hydrogel included glycol chitosan (GC) and dibenzaldhyde functionalized poly(ethylene oxide) network, and sodium alginate (Alg) and calcium chloride (CaCl2) network. To investigate its effectiveness, we applied this biphasic scaffold to repair osteochondral full-thickness defects in rabbit models. We set up six observation groups in total, including Untreated group, Microfracture group, BG only group, DN gel group, bi-DN gel group, and bi-DN/TGF-β gel group. With a follow-up period of 24 weeks, we evaluated the treatment effects by gross observation, micro-CT scan and histological staining. Besides, we further fulfilled the quantitative analysis of the data from ICRS score, O’Driscoll score and micro-CT parameters. The results revealed that neat GC/Alg DN hydrogel scaffold was only conductive to promoting cartilage regeneration and neat BG scaffold merely showed the excellent ability to reconstruct subchondral bone. While the biphasic scaffold performed better in repairing osteochondral defect synchronously, exhibiting more well-integrated cartilage-like tissue with positive staining of toluidine blue and col II immunohistochemistry, and more dense trabecular bone connecting closely with the surrounding host bone. Therefore, this method possessed the clinical application potential in treating articular injury, osteochondral degeneration, osteochondral necrosis, and sclerosis.

This review focuses on the research progress of sulfide solid electrolytes. Two systems of (100-x)Li2S-xP2S5 and Li2S-MxSy-P2S5 are systematically reviewed from four aspects, the crystal structure, conductivity, stability and application. The methods for preparing sulfide solid electrolytes are summarized, and, their advantages and disadvantages are compared and analysed. Sulfide solid electrolytes with high conductivities are closely related to their crystal structures, and they can be improved via doping, such as substitution doping, interstitial doping, dual-doping, etc. The conductivities are introduced and summarized according to their classifications. Experimental studies and theoretical results are discussed in parallel to illustrate the relationship between the conductivity and crystal structure. Furthermore, the stabilities of sulfide electrolytes with lithium metal, active materials, organic solvents and humid air are reviewed separately, and corresponding methods for improvement are proposed. Finally, according to the different functions of sulfide electrolytes in all-solid-state lithium batteries (ASSLBs), they are categorized and generalized scientifically in terms of composite electrolyte, buffer material and electrolyte. Additionally, the techniques proposed in the recent works to achieve sufficient contact between the sulfide solid electrolyte and the electrode in the ASSLBs are summarized. The present review aims to provide a thorough understanding of the properties of sulfide solid electrolytes, including conductivity, structure, and stability, to allow for more efficient and target-oriented research to improve the performance of sulfides-based ASSLBs.

In this work, we developed a very facile strategy, i.e. dual dynamic crosslinking, to prepare a high performance injectable hydrogel. Poly(vinyl alcohol) (PVA) was crosslinked by 4-carboxyphenylboronic acid (CPBA) through the generation of borate bonding and ionic interaction to bridge the polymer chains in the presence of calcium ions. The dynamic gathering of CPBA could induce a self-reinforcing effect inside the hydrogel matrix, leading to high tensile and compressive moduli of the hydrogel over 1.0 MPa including the highest compressive modulus up to 5.6 MPa. Meanwhile, the mechanical properties of the hydrogel can be broadly and accurately tuned. And owing to the flexible PVA network, the hydrogel is ultra-tough, showing maximum tensile strain, tensile and compressive fracture energies up to 1600%, 600 kJ m−2 and 25 kJ m−2, respectively. Besides, the dynamic bonding overcomes the barriers to forming an injected strong hydrogel, e.g. to obtain a modulus and a fracture energy exceeding 1.0 MPa and 40 kJ m−2, by using a commercial dual-syringe kit under physiological conditions. Such a mild gelation procedure benefits the administration, 3D encapsulation and proliferation of cells of the hydrogels. The application of the PVA hydrogel was demonstrated by effective cartilage repair.

For treating bone defects in periarticular fractures, there is a lack of biomaterial with injectable characteristics, tough structure, and osteogenic capacity for providing a whole-structure support and osteogenesis in the defect area. An injectable hydrogel is an ideal implant, however is weak as load-bearing scaffolds. Herein, a new strategy, i.e., an in situ formation of "active" composite double network (DN), is raised for the preparation of an injectable strong hydrogel particularly against compression. As a demonstration, 4-carboxyphenylboronic acid grafted poly(vinyl alcohol) (PVA) is crosslinked using calcium ions to provide a tough frame while bioactive glass (BG) microspheres are associated by poly(ethylene glycol) to obtain an interpenetrated inorganic network for reinforcement. The injected PVA/BG DN hydrogel gains compressive strength, modulus, and fracture energy of 34 MPa, 0.8 MPa, and 40 kJ m-2 , respectively. Then, the properties can be "autostrengthened" to 57 MPa, 2 MPa, and 65 kJ m-2 by mineralization in 14 days. In vivo experiments prove that the injected DN hydrogel is more efficient to treat femoral supracondylar bone defects than the implanted bulk DN gel. The work suggests a facile way to obtain a strong hydrogel with injectability, cytocompatibility, and tailorable functionality.

Three types of inorganic electrolytes [Li10GeP2S12 (LGPS), 75Li2S·24P2S5·1P2O5 (LPOS), Li1.5Al0.5Ge1.5(PO4)3 (LAGP)] with different particle sizes and electrochemical properties are selected as active fillers incorporated into poly(ethylene oxide) (PEO) matrix to fabricate hybrid solid electrolytes. The optimum composition of each filler is found in consideration of ionic conductivity. Their electrochemical characteristics are investigated. The optimal conductivities are 1.60 × 10−5, 1.18 × 10−5, and 2.12 × 10−5 S cm−1 at room temperature for PEO-1%LGPS, PEO-1%LPOS, and PEO-20%LAGP, respectively. The electrochemical stability windows of these hybrid solid electrolytes are all above 5 V (vs. Li+/Li). The results show that these fillers have positive effects on the ionic conductivity, lithium ion transference number, and electrochemical stability. The relationship between the type of filler and electrochemical properties has been investigated. All-solid-state cells LiFePO4/Li are fabricated and present fascinating electrochemical performance with high capacity retention and good cycling stability. This work provides promising electrolytes prepared by a simple method.

A new class of copolymer electrolytes with tunable network structure is successfully designed and prepared via a facile one-pot reaction. The trimethylolpropane triglycidyl ether (TMPEG) is cross-linked with poly (ethylene glycol) diamine (NPEG) to create well-defined solid network polymer electrolyte (SNPE). The network structure could be tuned by changing the molar ratio of TMPEG and NPEG or the molecular weight of NPEG. The effects of molecular weight of NPEG and molar ratio of EO/Li + on the ionic conductivity are systematically investigated. The optimal electrolyte TMPEG-NPEG4K[2:1]-16:1 presents a maximum conductivity of 1.10 × 10 −4 S cm −1 under 30 °C, and an 18-fold ionic conductivity enhancement in that of PEO-based electrolyte. Furthermore, it also exhibits wide electrochemical window (0–5.4 V), excellent compatibility with metallic Li, and superior mechanical properties. The all-solid-state lithium batteries LiFePO 4 /Li are assembled with TMPEG-NPEG4K[2:1]-16:1 electrolyte, and present good cycling and rate performance under 60 °C. The initial discharge specific capacities of the batteries are 161.7 mAh g −1 at 0.2 C and 132.7 mAh g −1 at 1 C, and the capacity retention ratio can be retained at 90.6% and 90.5% after 100 cycles. This new copolymer electrolyte may become a promising candidate for applications in all-solid-state lithium battery.

Four types of Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) with different particle sizes are selected as active fillers incorporated into polyethylene oxide (PEO) matrix to fabricate PEO/LAGP hybrid electrolytes at drying room. The results show that LAGP particles have a positive effect on the ionic conductivity, lithium ion transference number, electrochemical stabilities and mechanical properties. Among the PEO/LAGP hybrid electrolytes, the PEO-20%LAGP-I hybrid electrolyte exhibits a maximum ionic conductivity of 6.76 × 10 − 4 S cm − 1 and an electrochemical window of 0–5.3 V at 60 °C. The possible reasons for conductivities improving are discussed through characterizing the phase transition behaviors of electrolytes. All-solid-state battery LiFePO 4 /Li is fabricated and presents fascinating electrochemical performance with high capacity retention (close to 90% after 50 cycles at 60 °C) and attractive capacities of 166, 155, 143 and 108 mAh g − 1 at current rates of 0.1, 0.2, 0.5 and 1 C, respectively. This work provides a promising PEO/LAGP hybrid electrolyte prepared by a simple method which can be manufactured easily in industry scale.

Concerns regarding microplastic contamination have spread from aquatic environments to terrestrial systems with a growing number of studies have been reported. Notwithstanding, the potential effects on soil ecosystems remain largely unexplored. In this study, the effects of polyethylene microplastics on soil enzymatic activities and the bacterial community were evaluated, and the microbiota colonizing on microplastics were also investigated. Microplastic amendment (2000 fragments per kg soil) significantly increased the urease and catalase activities in soil after 15 days, and no discernible alteration of invertase activities was detected. Results from high-throughput sequencing of 16S rRNA revealed that the alpha diversities (richness, evenness, and diversity) of the microbiota in soil were not obviously changed by the PE amendment, whereas the diversity indexes of microbiota on plastic fragments were significantly lower than those in the control and amended soils. Different taxonomic composition was observed in between the control and amended soils after 90 days of incubation. Bacterial assemblages with distinct community structure colonized the PE microplastics. Additionally, several taxa including plastic-degrading bacteria and pathogens were more abundant on microplastics. Simultaneously, the predicted functional profiles showed that the pathways of amino acid metabolism and xenobiotics biodegradation and metabolism were higher on the microplastics. These results indicated that microplastics in soil, compared with those in aquatic environments, can also act as a distinct microbial habitat, potentially altering the ecological functions of soil ecosystems.

In this study, carbide slag loaded on ferric oxide (CS/Fe2O3) was synthesized as the catalyst for the transesterification of the soybean oil to biodiesel. The results indicated that CS/Fe2O3 catalyst showed superior catalytic activity and stability for the transesterification, which was related to the formation of Ca2Fe2O5 phase in the catalyst. In addition, the catalytic activity of CS/Fe2O3 was also affected by the precursors of the support and the molar ratio of calcium and iron in the catalyst. The catalyst with ferric chloride as the precursor performed the best catalytic performance, which was associated with the smallest mean pore diameter and the largest specific area. In addition, ferric oxide as a support could improve the stability of the CS/Fe2O3. Physical and chemical indexes of the produced biodiesel were analyzed and the results showed that the properties of the fuel met the requirement of the American Society for Testing Materials standard to be used as a green alternative source of the diesel.