Latest ArticlesThe micro-dispersion structure of silica fillers exerts significant influences on the performance characteristics of rubber-based products. How to monitor this parameter is an important issue in the rubber industry, but there is currently no suitable technical solution for numerical monitoring that can be applied in automatic production line. The labeling of silica in rubber is a challenge that bottlenecks the development of numerical quality monitoring technology. In this work, we employed the organometallic europium to modify silica endowing the fluorescence properties for characterization. It provides more feasible solutions for visually studying the relationship between the submicroscopic structure and macroscopic properties of inorganic-filled polymers, and is the key foundation for achieving numerical monitoring of rubber filler qualities in industry.
A thickness-controllable method for preparing metal-organic framework hollow nanoflowers on magnetic cores (Fe3O4@MOFs HFs) was demonstrated for the first time. The petal of magnetic core with hollow nanoflower structure served as medium for assembling UiO-66-NH2 shell with different thickness. To further improve its performance, Zr4+ was immobilized on the surface of Fe3O4@UiO-66-NH2. Compared with conventional Fe3O4@UiO-66-NH2-Zr4+ nanospheres, the Fe3O4@UiO-66-NH2-Zr4+ HFs showed increased enrichment performance for phosphopeptides. The Fe3O4@UiO-66-NH2-Zr4+ HFs served as an attractive restricted-access adsorption material exhibited good selectivity (mβ-casein:mBSA=1:1000), high sensitivity (1.0 fmol) and excellent size-exclusion effect (mβ-casein digests:mBSA=1:200). Furthermore, the Fe3O4@UiO-66-NH2-Zr4+ HFs was successfully applied to the specific capture of ultratrace phosphopeptide from complex biological samples, revealing the great potential for the identification and analysis of trace phosphopeptides in clinical analysis. This work can be easily extended to the fabrication of diverse mag-MOF HFs with multifunctional and easy to post-modify properties, and open up a new avenue for the design and construction of new MOFs material.
Polyetheretherketone (PEEK) is a desirable candidate to replace conventional metal implants owing to its excellent mechanical properties. However, the intrinsic bioinertness of PEEK results in inferior or delayed osseointegration, which limits its further clinical application. To address these challenges, one leading strategy is to construct a biofunctionalized surface on PEEK that provides a coordinated osteoblast-osteoclast interactions microenvironment. Herein, alendronate (ALN), a common bone absorption inhibitor, was loaded in biomedical inorganic/organic microspheres, consisting of bioactive inorganic nano-hydroxyapatite core, and chitosan (CS) shell. Polydopamine (PDA) modification was employed to ensure the adherence of the microspheres to the PEEK surface. The delivery of ALN and Ca2+ from these microspheres simultaneously suppressed osteoclastogenesis and promoted osteogenesis, resulting in a coordinated cascade of osteoblast-osteoclast interactions crucial for the per-implant osseointegration. In vitro experiments demonstrated that the PEEK surface exhibited satisfactory biocompatibility and enhanced the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells while inhibiting the osteoclast differentiation. Moreover, the in vivo rat femoral drilling model demonstrated superior osseointegration three months after implantation. By considering the bone remodeling processes, this study proposes a novel biofunctionalized PEEK surface that regulates the activities of both osteoblasts and osteoclasts to promote osseointegration.
The widespread occurrence of antibiotics in wastewater aroused serious attention. UV-based advanced oxidation processes (UV-AOPs) are powerful technologies in removing antibiotics in wastewater, which include UV/catalyst, UV/H2O2, UV/Fenton, UV/persulfate, UV/chlorine, UV/ozone, and UV/peracetic acid. In this review, we collated recent advances in application of UV-AOPs for the abatement of fluoroquinolones (FQs) as widely used class of antibiotics. Representative FQs of ciprofloxacin, norfloxacin, ofloxacin, and enrofloxacin were most extensively studied in the state-of-art studies. The evolvement of gas-state and solid-state UV light sources was presented and batch and continuous flow UV reactors were compared towards practical applications in UV-AOPs. Generally, degradation of FQs followed the pseudo-first order kinetics in UV-AOPs and strongly affected by the operating factors and components of water matrix. Participation of reactive species and transformation mechanisms of FQs were compared among different UV-AOPs. Challenges and future prospects were pointed out for providing insights into the practical application of UV-AOPs for antibiotic remediation in wastewater.
Multiple donor-acceptor (D-A) combinations represent a promising category of thermally activated delayed fluorescence (TADF) materials, offering potential for superior efficiency and stability. However, current systems are predominantly composed of limited donor groups, primarily carbazole-based derivatives. In this work, we developed a series of D-A type materials incorporating helical π-expanded carbazole (CzNaph) and 7H-dinaphtho[1,8-bc:1′,8′-ef]azepine (AzNaph), alongside traditional carbazole, ranging from mono- to tetra-substituted configurations (Dn-A). Through systematic investigation of geometric and electronic structures, the number and positioning of multiple donors are confirmed with significant manipulations on charge transfer characteristics and the S1 state via steric effects. Density functional theory (DFT) calculations reveal that varying the number of π-extended donors within the acceptor framework produces emission colors from ultraviolet to red, providing a diverse range of emitters. Furthermore, the reduced reorganization energy of S1 observed in tetra-substituted Cz and CzNaph, as well as MonoAzN, indicates lower structural relaxation, highlighting these materials' potential as stable luminescent candidates. This study underscores the importance of diverse composing units in achieving efficient and stable TADF emitters with multiple and hetero-donor configurations.
In response to the increasing demand of ethylene, electrochemical ethane nonoxidative dehydrogenation (EENDH) to ethylene by protonic ceramic electrolysis cells (PCECs) is developed. However, existing anode materials exhibit poor proton conductivity and limited catalytic activity. Herein, a novel Sr1.95Fe1.4Co0.1Mo0.4Zr0.1O6-δ (SFCMZ) anode is prepared as PCECs anode for EENDH. Zr doping increases the oxygen vacancies and enhances the proton conductivity of SFCMZ. Moreover, an alloy-oxide heterostructure (CoFe@SFCMZ) is formed through in-situ exsolution of CoFe alloy nanoparticles under reduction conditions, generating abundant oxygen vacancies and improving its catalytic activity. CoFe@SFCMZ cell achieves an electrolysis current density of 0.87 A/cm2 at 700 ℃ under 1.6 V, with an ethane conversion rate of 34.22% and corresponding ethylene selectivity of 93.4%. These results demonstrate that CoFe@SFCMZ anode exhibits excellent electrocatalytic activity, suggesting promising applications for EENDH.
PVDF-based nanocomposites have gained significant focus in capacitors for their excellent dielectric strength, its multi-scale structural inhomogeneity is the bottleneck for improving the energy storage performance. Here, the composite components are optimized by the matrix modification, BST (Ba0.6Sr0.4TiO3) ceramic fibrillation and surface coating. A series of PVDF/polymethyl methacrylate/lysozyme@BST nanofibers with continuous gradient distribution (PF-M/mBST nf-g) are prepared by the concentration gradient-biaxial high-speed electrospinning. The finite element simulation and experiment results indicate that the continuous gradient structure is favorable for the microstructure and inhomogeneity of the electric field distribution, significantly increasing the breakdown strength (Eb) and the permittivity (εr), as well as effectively suppressing the interfacial injected charge and leakage current. As a result, the energy storage density (Ue) of 23.1 J/cm3 at 600 MV/m with the charge-discharge efficiency (η) of 71% is achieved compared to PF-M (5.6 J/cm3@350 MV/m, 65%). The exciting energy storage performance based on the well-designed PF-M/mBST nf-g provides important information for the development and application of polymer nanocomposite dielectrics.
Developing efficient electrocatalysts for oxygen evolution reaction (OER) is imperative to enhance the overall efficiency of electrolysis systems and rechargeable metal-air batteries operating in aqueous solutions. High-entropy materials, featured with their distinctive multi-component properties, have found extensive application as catalysts in electrochemical energy storage and conversion devices. However, synthesizing nanostructured high-entropy compounds under mild conditions poses a significant challenge due to the difficulty in overcoming the immiscibility of multiple metallic constituents. In this context, the current study focuses on the synthesis of an array of nano-sized high entropy sulfides tailored for OER via a facile precursor pyrolysis method at low temperature. The representative compound, FeCoNiCuMnSx, demonstrates remarkable OER performance, achieving a current density of 10 mA/cm2 at an overpotential of merely 220 mV and excellent stability with constant electrolysis at 100 mA/cm2 for over 400 h. The in-situ formed metal (oxy)hydroxide has been confirmed as the real active sites and its exceptional performance can be primarily attributed to the synergistic effects arising from its multiple components. Furthermore, the synthetic methodology presented here is versatile and can be extended to the preparation of high entropy phosphides, which also present favorable OER performance. This research not only introduces promising non-noble electrocatalysts for OER but also offers a facile approach to expand the family of nano high-entropy materials, contributing significantly to the field of electrochemical energy conversion.
Hyperforatone A (1), the 1,8-seco rearranged polycyclic polyprenylated acylphloroglucinol, possessed an unusual bicyclo[5.4.0]undecane skeleton bearing a 5/7/6/5 ring system, and two known biosynthetically related precursors (2 and 3) were isolated from Hypericum perforatum (St. John’s wort). The structure and absolute configuration were unambiguously confirmed by a combination of comprehensive spectroscopic data, computational methods including residual dipolar couplings (RDCs), and X-ray crystallography. Density functional theory (DFT) calculations revealed that the cationic cyclization reaction was key to proposed formation mechanism for hyperforatone A. Furthermore, in vitro and in vivo experiments demonstrated that compound 1 was a potential anti-neuroinflammatory agent.