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Mechanically robust superhydrophobic coatings have been extensively reported using chemically susceptible inorganic fillers like SiO2, TiO2, ZnO, etc. for constructing micro-nano structures. Organic particles are good candidates for improving chemical resistance, whereas the synthesis of organic particles with well-defined and stable micro-nano structures remains exclusive. Here, an all-organic, cross-linked superhydrophobic coating comprising raspberry-like fluorinated micro particles (RLFMP) and fluorinated polyurethane (FPU) was prepared via thiol-click reaction. Benefiting from the robust micro-nano structure of RLFMP and the excellent flexibility of FPU, the coating could maintain superhydrophobic after severe alkali corrosion or mechanical damage, while the superhydrophobicity could be repaired readily by the fast recovery of micro-nano roughness and migration of branched fluoroalkyl chains to the coating surface. Our design strategy is expected to provide a good application of thiol-click chemistry. This article is protected by copyright. All rights reserved.

The catalytic hydrogen transfer (CHT) cascade reaction between alcohols and nitro- compounds meets green chemistry yet involves high catalyst requirements. Herein, a hierarchical nano-pyramid structure, in which cobalt single atoms (Co SAs) are deposited on highly dispersed ZnO nanoparticles supported by nitrogen-doped carbon (denoted as Co-ZnO/NC), was designed and obtained through pyrolysis of ZnCo-ZIF. The catalyst exhibited excellent catalytic performance toward the CHT cascade reaction, achieving a high nitrobenzene conversion (94 %), imine selectivity (97 %), and turnover frequency (8.8 h−1). This nano-pyramid is a state-of-the-art non-noble-metal catalyst and is comparable to noble-metal catalysts. Experimental and DFT results revealed that the Co SAs supported on ZnO reduced the reaction energy barrier of hydroxyl dehydrogenation, the first and rate-determining step in this heterogeneous catalysis. Furthermore, Co-ZnO/NC exhibits good recyclability and universality. Our findings offer a new catalyst for Schiff base synthesis and aid understanding of the roles of Zn in ZIF-derived carbon catalysts.

The seawater contains 4.5 billion tons of uranium(VI), which is quite enough to provide a continuous supply of infinite nuclear energy. However, it is a sudden need to develop adsorbents from abundant available source, easy collect property, large durability and high uranium(VI) adsorption capacity from seawater. In this work, a single-step process was developed for the preparation of chitosan (Cs) functionalized tubular carbon nanocomposite microspheres (CsFTnCM) for efficient uranium(VI) adsorption from seawater. The application of newly synthesized adsorbent for uranium(VI) removal from seawater is explored. Thus prepared adsorbent (CsFTnCM2) is found to adsorb 99.5% uranium(VI) from seawater. The CsFTnCM2 (Cs/FTn,1:1) comprising NH2 and COOH content approximately 0.61 mmol/g and 0.23 mmol/g, respectively. This kind of adsorbent possessed a uranium(VI) loading capacity of 0.660 (mg/g) from seawater. The adsorption kinetics not only dependent on the physical structure of the adsorbent but depends on the proportion of FTn in the Cs-matrix. However, the kinetics of uranium(VI) adsorption was increased by increasing the content of FTn up to a certain limit. The adsorption efficiency of uranium(VI) was not affected by the presence of coexisted ions, whose concentration is 1000 times greater than uranium(VI) in seawater. The desorption of uranium(VI) from the seawater exposed adsorbents were investigated and the results showed the uranium(VI) strip from the adsorbents found to be efficiently using Na2CO3.

Summary To explore the relative contributions of higher-order and primary visual cortex (V1) to visual perception, we compared cats' behavioral and V1 neuronal contrast sensitivity functions (CSF) and threshold versus external noise contrast (TvC) functions before and after top-down influence of area 7 (A7) was modulated with transcranial direct current stimulation (tDCS). We found that suppressing top-down influence of A7 with cathode-tDCS, but not sham-tDCS, reduced behavioral and neuronal contrast sensitivity in the same range of spatial frequencies and increased behavioral and neuronal contrast thresholds in the same range of external noise levels. The neuronal CSF and TvC functions were highly correlated with their behavioral counterparts both before and after the top-down suppression. Analysis of TvC functions using the Perceptual Template Model (PTM) indicated that top-down influence of A7 increased both behavioral and V1 neuronal contrast sensitivity by reducing internal additive noise and the impact of external noise., Graphical abstract, Highlights • Top-down suppression lowers both behavioral and V1 neuronal CSF functions • Top-down suppression raises both behavioral and V1 neuronal TvC functions • The neuronal CSFs and TvCs are highly correlated with their behavioral counterparts • Top-down influence lowers internal additive noise and impact of external noise in V1, Biological science, Behavioral neuroscience, Sensory neuroscience, Visual neuroscience

A series of benzyl alcohol (BA)-based hyper-cross-linked microporous polymers (HCPs) were designed and synthesized via facile Friedel–Crafts alkylation using formaldehyde dimethyl acetal (FDA) as external cross-linker promoted by anhydrous ferric chloride (FeCl3). Results demonstrated that Brunauer–Emmett–Teller (BET) specific surface area and pore volume for the HCPs could be controlled by adjusting the amount of FDA and FeCl3. The HCPs obtained under optimal conditions showed a BET specific surface area up to 1101 m2/g, whose capacity of CO2 uptake could be as high as 3.03 mmol/g at 273 K/1.0 bar. The isosteric heats of CO2 sorption for the BA-based HCPs exceed 27 kJ/mol at the low coverage. In addition, the polymer networks possessed high CO2/N2 selectivity of 42. Compared with those BA-based HCPs which is without FDA, the prepared material has higher BET specific surface area and superior CO2 adsorption properties. These results demonstrated that these prepared HCPs are promising for CO2 capture and s...

Background: Glucocorticoids, including dexamethasone (Dex), are corticosteroids secreted by the adrenal gland, which are used as potent anti-inflammatory, anti-shock, and immunosuppressive agents. Dex is commonly used in patients with malignant tumors, such lung cancer. However, administration of high-dose Dex induces severe atrophy of the skeletal muscle, and the underlying mechanisms of this skeletal muscle atrophy remain unclear. Abundant miRNAs of skeletal muscle, such as miR-351, play an important role in the regulation of extenuating the process of muscle atrophy. Methods: The mRNA and protein expression of TRAF6, MuRF1, MAFbx was determined by real-time PCR and western blot, while the expression of miR-351 was detected by real-time PCR. The myotubes were transfected with miR-351 mimic, negative control, or miR-351 inhibitor. The C2C12 myotubes diameter was measured. Results: MicroRNA351 (miR-351) level was markedly reduced and the mRNA and protein levels of tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) were increased in Dex-induced C2C12 myotube atrophy. miR-351 directly interacted with the 3'-untranslated region (3'UTR) of TRAF6. Interestingly, miR-351 administration notably inhibited the reduction of the C2C12 myotube diameter induced by Dex treatment and reduced the levels of TRAF6, muscle-RING-finger protein-1 (MuRF1), and muscle atrophy F-box (MAFbx). Conclusions: miR-351 counteracts Dex-induced C2C12 myotube atrophy by repressing the TRAF6 expression as well as E3 ubiquitin ligase MuRF1 and MAFbx. miR-351 maybe a potential target for development of a new strategy for skeletal muscle atrophy.

Low durability is a potential Achilles heel for superhydrophobic coatings, which greatly prevents applications of superhydrophobic materials for various daily living activities. In this paper, a novel branched epoxy, dangling long fluoroalkyl tail, was designed and synthesized. The coating shows contact angles of 165°, 147° and 144° to water, glycol and colza oil, respectively, and shows superhydrophobicity. This coating is also highly durable, withstanding at least 1000 abrasion cycles under 45 kPa. After abrasion testing, its contact angle to water is maintained at 152°. Furthermore, this coating also shows a remarkable stability towards strong acid, UV light, thermal and smudge treatment without apparently losing its superhydrophobicity. The epoxy groups of the T-FAE can form high crosslinking network by the ring-opening reaction and reacting with the Si OH and NH2, and long-fluorine chain offers low surface energy. All these are responsible for the excellent performance of the coating.

We proposed a facile and versatile strategy to prepare a novel immobilized enzyme, through fabricating Candida rugosa lipase (CRL)/inorganic hybrid nanosheets on sulfonated macroporous resins (SMRs). The lipase/Ca3(PO4)2 on SMRs not only shows the high catalytic activity inheriting from lipase/Ca3(PO4)2 hybrid nanostructures, but also possesses high strength and excellent operational stability endowed by protection of SMRs, which is more suitable for industrial application. The optimal immobilization conditions, the best catalytic conditions and its operational stability were systematically investigated. The observed maximum enzyme activity could reach 3176.11 ± 16.64 U/g protein under the optimal immobilized conditions, approximately 112% higher than free lipase. When the catalytic reaction was conducted in phosphate buffer (0.05 M, pH 8.0) at 60 °C, the immobilized lipase had the highest activity while the activity of the free lipase decreased sharply, which showed a remarkably increased tolerance performance compared with free lipase benefiting from the SMRs. As a biocatalyst, the immobilized lipase for batch hydrolysis of olive oil emulsion retained 81.6% activity after 10 times of recycling at pH 7.0 and 30 °C, which indicated that the well-designed carrier materials would be very valuable and meaningful in industrial enzyme catalysis.

The redox properties of different crystal structure MnO2 in organic reactions at low temperature of 60 °C were disclosed. Among the three crystal structures (α-, β- and γ-types), γ-MnO2 showed unusual high heterogeneous catalytic performance, reusability and stability for imine formation from benzyl alcohol and aniline under mild conditions. The yield of imine over γ-MnO2 reached up to 98.1% in 12 h under air atmosphere and its formation rate per surface area was 27.9 μmol h−1 m−2, and various imines could be obtained in excellent yield over γ-MnO2. Based on series of catalyst characterizations, it was found that the high activity of γ-MnO2 was mainly attributed to its high concentration of low-valence manganese ions. Furthermore, the catalytic mechanism was also disclosed. This research may have certain reference value for heterogeneous catalytic reactions by manganese.

In this work, a novel flowerlike BSA/Zn3(PO4)2/Fe3O4 magnetic hybrid particle is successfully synthesized through a simple and rapid one-step strategy. The kernel is to introduce Fe3O4 nanoparticle...

Vitrimers have been emerged as a new class of polymers with many attractive properties of material processing such as reshaping, recycling and repairing. Herein, a new type of vitrimers (BDSER) based on thermosetting dynamic epoxy network with double disulfide bonds was synthesized by the reaction of a difunctional epoxy monomer containing disulfide bonds with 4,4′-disulfanediyldianiline (4-AFD). Our results demonstrated that the relaxation time of BDSER at 200 °C was as short as 9 s without any catalyst. The storage modulus of BDSER was up to about 2.2 GPa and its glass transition temperature was higher than 130 °C. Additionally, the thermodynamic and chemical properties of BDSER were no significant loss after 3 cycles of continuous breaking/compression molding. Furthermore, the resistance of CNT/PPy/Vitrimer composites (CPV), synthesized by doped BDSER with the polypyrrole (PPy) decorated multi-walled carbon nanotubes (WMCNTs), was decreased to 109 Ω even the mass ratio was only 1%wt, which could be used a promising candidate as self-repairing materials in the field of antistatic.

Aiming at obtaining the polyolefin blends potentially applied in the field of the super-tough polymer products, in this work, isotactic polypropylene (iPP)/styrene-ethylene-butadiene-styrene block copolymer (SEBS) blends with great impact toughness were successfully fabricated by adding traces of β-nucleating agents (β-NAs) and carbon nanotubes (CNTs). The impact toughness of iPP blends with 30 wt% SEBS was as high as 62.4 kJ/m2, when simultaneously containing 0.1 wt% β-NAs and 0.05 wt% CNTs. Their toughness was about 13.1 kJ/m2 more than iPP blends with 30 wt% SEBS and 0.1 wt% β-NAs, 49.6 kJ/m2 more than iPP blends with 30 wt% SEBS and 0.05 wt% CNTs, and almost 22.3 times of pure iPP. The iPP matrix with abundant self-toughed β-crystals generated by β-NAs, the quasi-cocontiunous morphology of the SEBS dispersed phase as well as some small SEBS droplets induced by CNTs in the iPP matrix, and the good interfacial compatibility between SEBS and the iPP matrix all harmoniously took effect to synergistically enhance the toughness of iPP blends.

Understanding the biaxial mechanical behavior of steel fiber reinforced concrete (SFRC) is of critical significance when the concrete structures are subjected to dynamic loading. This paper presents the results of an experimental investigation on the dynamic mechanical behavior of SFRC subjected to biaxial compressive loadings. Aiming at the combined effects of steel fiber and strain rate on strength criterion, a series of dynamic biaxial compressive experiments on 100 mm-length SFRC cubic specimens with various steel fiber contents (0%, 1%, 2%, and 3% by volume) were conducted by using a large dynamic triaxial servo-hydraulic testing apparatus. The specimens were loaded by biaxial compression with five stress ratios (i.e. 0:1, 0.25:1, 0.5:1, 0.75:1 and 1:1, respectively) at various strain rates ranging from 10−5/s to 10−2/s. A comprehensive dynamic biaxial strength criterion taking into account the combined effects of uniaxial strength, strain rate and stress ratio was proposed. The effect of steel fiber content and strain rate on the biaxial mechanical behavior of SFRC specimens was discussed, including the failure mode, stress-strain curve, biaxial compressive strength, dynamic strength criterion. It suggested that at given strain rate, the biaxial stress ratio is the major factor dominating the strength increment, and the incorporation of steel fiber has a remarkable enhancement on the strength for all stress ratios. Additionally, the dynamic compressive strengths of SFRC were found to increase with the increase of strain rate, while the failure pattern and dynamic ultimate strength were closely dependent on the magnitude of lateral stress exerted on the specimens. The comparison indicates that the proposed model results of dynamic strength criterion were in good agreement with the experimental data for SFRC specimens.

Polyimine vitrimers are a promising class of self-healing materials for their attractive dynamic reversible properties and ease of preparation without catalysts, but they still remain some challenges to overcome, such as poor mechanical properties and thermal stability or a higher temperature to reprocess and recycle. Herein, performance-modified polyimine vitrimers, combining flexibility, good mechanical properties and thermal stability with easy reprocessed/recycle properties, were studied by introducing aromatic diamines dimer (m-xylylenediamine dimer) into the polymer networks. The incorporation of m-xylylenediamine dimer increases the molecular chain of polymer networks, which makes the material more flexible and easy reprocessed. Besides, it owns two benzene rings and endows the dynamic polymer with broaden conjugation structure, which remains the material’s thermal stabilities and mechanical properties. Results show that the polymer material exhibits flexibility at room temperature [a glass transition temperature (Tg) of 72 °C, a storage modulus of = 1.56 GPa and stress at break of = 45 MPa (dry sample) and 27 MPa (wet sample)], possesses excellent thermal stability (a mass loss of 6.3% at 300 °C) and performs viscoelastic liquid behavior in very short relaxation times at lower temperatures (from 260 s at 70 °C to 22 s at 100 °C). In addition, the obtained networks could be more easily reprocessed and remolded in shorter times and at lower temperatures under the condition of heat, water and amine solvents without adding any catalyst.

Along with the wide development of protein imprinted polymers, the researchers still face many challenges, such as difficult template elution, slow adsorption rate and low adsorption capacity. In order to promote the progress of protein separation and purification, the surface imprinted manganese dioxide-loaded tubular carbon fibers (FTCFs@MnO2@MIPs) are prepared in this work. FTCFs@MnO2@MIPs are based on tubular carbon fibers (TCFs) coated with flaky MnO2. Dopamine (DA) and bovine serum albumin (BSA) are utilized as functional monomers and templates. The MnO2 nanosheets are grown and loaded on the surface of carboxyl-modified tubular carbon fibers (CMTCFs) to form a MnO2 shell, which provides more imprinting sites for protein imprinting. Meanwhile, this shell enhances the interaction between the imprinting sites and BSA. The content of MnO2 loaded on the surface of CMTCFs is 9.42%. The obtained materials are systematically characterized and the adsorption performances of FTCFs@MnO2@MIPs for BSA are investigated. The adsorption process of FTCFs@MnO2@MIPs exhibits significant self-driven characteristics. The adsorption capacity reaches 816.44 mg/g in 60 min and the imprinting factor (IF) is 3.31. FTCFs@MnO2@MIPs can selectively separate BSA from the mixed proteins and fetal bovine serum. Excellent reusability and practical application ability make MnO2-loaded tubular carbon fibers (FTCFs@MnO2) become a promising carrier in the field of protein imprinting.

In this paper, an efficient and green strategy was developed to synthesize porous magnetic chitosan (PMCS) particles via a special superhydrophobic effect of a porous fluorinated polyimide (PFPI) f...

Nanocomposites are fabricated with poly (glycidyl methacrylate) (PGMA) microspheres, Au nanoparticles and hyaluronic acid (HA) for accurate photothermal therapy. PGMA microspheres are synthesized by emulsifier-free emulsion polymerization followed by amination. The adsorption of gold seeds is successfully achieved through chelation. PGMA@Au-4 nanocomposites (abbreviated as PGMA@Au) are obtained after gold seed growth. The temperature of the 0.3 mg mL−1 PGMA@Au dispersion increases by 10.6 °C when irradiated with a near-infrared (NIR) laser for 5 min. In order to reduce side effects in normal cells and achieve a specific targeting property for cancer cells, HA is further conjugated on the surface of PGMA@Au (denoted as PGMA@Au–HA). The PGMA@Au–HA nanocomposites perform highly selective targeting toward cancer cells and have good photothermal properties, leading to threefold therapeutic efficacy against cancer cells in comparison with normal cells. These results indicate that the PGMA@Au–HA construct could be a promising platform for cancer therapy.

Thiol-epoxy elastomers were firstly prepared by thiol-epoxide nucleophilic ring-opening reaction, and the micron boron nitride (mBN) fillers were then introduced into the above system via in-situ polymerization, finally to prepare the highly thermally conductive, self-healing and recoverable mBN/thiol-epoxy elastomer composites by hot-pressing method. Results revealed that the thiol-epoxide reaction was highly efficient and stable. The obtained mBN/thiol-epoxy elastomer composite with 60 wt% mBN fillers presented the optimal thermal conductivity (λ of 1.058 W/mK), excellent self-healing effect & efficiency which is achieved via transesterification reaction (Tensile strength after self-healing could maintain at more than 85% compared to that of original composites), wonderful recoverable performance (Tensile strength after post forming could maintain over 70% compared to that of original composites) and good thermal stability (Theat-resistance index, THRI of 149.9 °C). And the improvement in λ value of the mBN/thiol-epoxy elastomer composites was beneficial to the promotion of the self-healing systems relying on thermal response.

Five different nanocerias were prepared and used to catalyze the direct coupling of alcohol and amine to the corresponding imines under air atmosphere at low temperature. The catalytic efficiencies have great differences, CeO2 prepared by coprecipitation at room temperature (called CeO2-5) has the best catalytic activity, whose yield reaches 99% at 303 K for 36 h, 100 times higher than the nano-octahedras ceria (called CeO2-4) and also higher than the catalytic performance of most reported catalysts. Such phenomena are ascribed to the higher acidic sites, specific surface area, and proportions of surface oxygen. The results of DRIFTS demonstrated that the alcohol oxidized to benzaldehyde was the rate determining step in this reaction. Furthermore, CeO2-5 still shows excellent catalytic performance on 10-fold magnification experiments without any addition of solvent. Besides, it has the advantages of simple process, low energy consumption and practical scaling-up as well as good universality towards this kind of reaction, showing every prospect in industrial application.

Poly(p-phenylene terephthalamide) (PPTA) paper serves as a promising matrix candidate that exhibits reduced overall weight and possesses exceptional inherent dielectric strength, thermal durability, and excellent mechanical property and processing flexibility. However, PPTA broken paper in mill is regarded as the solid waste and is landfilled eventually, resulting in severe environmental pollution and waste of resources. In this work, for the first time, an efficient and high value-added approach is proposed for the recovery of aramid nanofibers (ANFs) from PPTA broken papers by controlled deprotonation in KOH/dimethylsulfoxide (DMSO) system. A stable and uniform ANF/water dispersion and the insulating ANF films were successfully obtained. In an effort to explore those possibilities, the effect of ultrosonicon on the compact structure of PPTA broken paper was first investigated. Then the formation process, micromorphology, thermostability, crystalline structure and formation mechanism of ANFs, and the key...

Porous solid with multimodal pore size distribution provides plenty of advantages including large specific surface area and superior mass transportation to achieve high gas-sensing performances. In this study, α-Fe2O3 nanoparticles with bimodal porous structures were prepared successfully through a nanocasting pathway, adopting the bicontinuous 3D cubic symmetry mesoporous silica KIT-6 as the hard template. Its structure and morphology were characterized by X-ray diffraction, nitrogen adsorption–desorption, transmission electron microscopy, and so on. Furthermore, the gas sensor fabricated from this material exhibited excellent gas-sensing performance to several volatile organic compounds (acetone, ethyl acetate, isopropyl alcohol, n-butanol, ethanol, and methanol), such as ultrahigh sensitivity, rapid response speed (less than 10 s) and recovery time, good reproducibility, as well as stability. These would be associated with the desirable pore structure of the material, facilitating the molecules diffusi...

DCPDCE/BADCy hybrid resin and BN fillers were performed to fabricate the thermally conductive BN/DCPDCE/BADCy composites. When the molar ratio of DCPDCE/BADCy was 0.4/0.6, the dielectric constant (e) and dielectric loss tangent (tgδ) value of the DCPDCE/BADCy hybrid resin was decreased to 2.92 and 5.08 × 10−3, respectively. Impact and flexural strength was increased to 10.7 kJ/m2 and 100.7 MPa, respectively. And the heat-resistance index (THRI) was 201.6 °C. Furthermore, the thermally conductive coefficient (λ) of the BN/DCPDCE/BADCy composite with 30 wt% BN fillers was improved to 0.64 W/mK, about 3 times in comparison to that of pristine DCPDCE/BADCy hybrid resin. Compared to that of Maxwell and Russell models, our proposed thermally conductive model could predict the experimental λ values more precisely. THRI value was enhanced from 201.6 °C (Pristine DCPDCE/BADCy hybrid resin) to 206.6 °C. Moreover, the BN/DCPDCE/BADCy composite with 10 wt% BN presented the optimal impact strength (11.7 kJ/m2) and flexural strength (108.4 MPa).

A series of Bi/BiOCl/TiO2-CQDs(α) (BBTC-α) quaternary photocatalysts with lamellar structure were synthesized via a solvothermal method followed by a hydrothermal process. The BBTC-0.6 photocatalyst exhibited highest visible-light photoactivity in decomposing methyl orange and p-nitrophenol, and it was about 4.8 and 10.3 times of BiOCl/TiO2 nanosheets. In this system, Bi and CQDs were served as electron donors, and BiOCl and TiO2 were served as electron trappers to extend the lifetime of photogenerated carriers. The enhanced visible-light photoactivity could be attributed to the strong light absorption and upconversion photoluminescence of the CQDs, and the surface plasmon resonance effect of the surface Bi also played an important role in this system.

Yolk–shell Fe3O4@N-doped carbon nanochains, intended for application as a novel microwave-absorption material, have been constructed by a three-step method. Magnetic-field-induced distillation-precipitation polymerization was used to synthesize nanochains with a one-dimensional (1D) structure. Then, a polypyrrole shell was uniformly applied to the surface of the nanochains through oxidant-directed vapor-phase polymerization, and finally the pyrolysis process was completed. The obtained products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and thermogravimetric analyses (TGA) to confirm the compositions. The morphology and microstructure were observed using an optical microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM). The N2 absorption–desorption isotherms indicate a Brunauer–Emmett–Teller (BET) specific surface area of 74 m2/g and a pore width of 5–30 nm. Investigations of the microwave absorption performance indicate that paraffin-based composites loaded with 20 wt.% yolk–shell Fe3O4@N-doped carbon nanochains possess a minimum reflection loss of −63.09 dB (11.91 GHz) and an effective absorption bandwidth of 5.34 GHz at a matching layer thickness of 3.1 mm. In addition, by tailoring the layer thicknesses, the effective absorption frequency bands can be made to cover most of the C, X, and Ku bands. By offering the advantages of stronger absorption, broad absorption bandwidth, low loading, thin layers, and intrinsic light weight, yolk–shell Fe3O4@N-doped carbon nanochains will be excellent candidates for practical application to microwave absorption. An analysis of the microwave absorption mechanism reveals that the excellent microwave absorption performance can be explained by the quarter-wavelength cancellation theory, good impedance matching, intense conductive loss, multiple reflections and scatterings, dielectric loss, magnetic loss, and microwave plasma loss.

A series of silica with diverse channel structures or pore diameters were synthesized via the hydrothermal method. Corresponding amine/nitro-modified materials were obtained by grafting, nitrating reaction, respectively. Textural and chemical properties were analyzed by Scanning electron micrograph (SEM), Small angle powder X-ray diffraction (SAXRD), Nitrogen adsorption-desorption measurement, Fourier transform infrared spectroscopy (FTIR), Thermogravimetric (TG) analysis and Zeta potential. Batch adsorption results revealed that distinct uptake capacities of Cu2+ and methylene blue occurred at the solid-liquid interface of prepared adsorbents. Especially, pure SBA-12-OH displayed the highest removal behavior toward methylene blue, mainly owing to its larger pore diameter. Amine-grafted SBA-12 (SBA-12-NH2) presented higher affinity to Cu2+ than others, originating from the complexation function of amine groups and its superior framework structure. Moreover, their adsorption isotherms and kinetics were further investigated to explore the application in industrial operation system.

A novel Fe3O4@SiO2@carbonized chitosan (Fe3O4@SiO2@CCS) porous magnetic microspheres are prepared through the combination technique of microfluidic, ionic crosslinking and hydrothermal carbonization. Modern characterization analysis shows that Fe3O4@SiO2@CCS microspheres are superparamagnetic and exhibit excellent pore performance. The carbonization time is investigated to study its influence on morphology, pore property, component and magnetic performance. Carbonization reaction is carried out from outside to inside and contained hydration condensation process. The as-obtained microspheres are used as adsorbents for removal of organic dyes from water. It is found that the microspheres prepared at 12 h (MSCCS-12) show greater advantage as the adsorbents. The adsorption isotherms can be fitted with Langmuir equation. The maximum adsorption capacity for RhB on MSCCS-12 estimated from the Langmuir model is 191.57 mg g−1 at 25 °C. A distinct advantage of Fe3O4@SiO2@CCS microspheres is that they can readily be isolated from solutions by application of an external magnetic field. The microspheres exhibit excellent reusability. The removal efficiency retained nearly 90% after fifteen successive cycles of reuse. Thus, the novel adsorbent shows potential application value in removal of organic dyes.

Superhydrophobic films with rapid, lasting self-healing behaviors against physical and chemical damage are very useful for practical applications but remain challenging to realize. Regeneration is time-consuming or invalid as self-healing cycles increase, especially for severe physical damage. Herein, a branched thiol-ene fluoroalkyl siloxane is introduced to design a self-healing superhydrophobic 3D sol-gel network dangling fluoroalkyl chain for coating treatment. The coated fabric was highly durable to withstand at least 1000 cycles of abrasion under 45 kPa and resistant to strong acid/base (e.g., H2SO4, KOH), UV, thermal, and smudge treatments. Moreover, regardless of severe physical or chemical damage, the coating rapidly restored its super liquid-repellent properties using long dangling perfluoroalkyl arms. This robust, rapid and long-term self-healing system may promote the development of long-lived protective films for various applications.

Aiming at the problems of existing speech authentication algorithms, such as poor robustness and discrimination, security vulnerability, low efficiency, poor ability of tamper detection and localization, a high-performance speech perceptual hashing authentication algorithm based on Discrete Wavelet Transform (DWT) and measurement matrix is proposed in this paper. Firstly, the speech signal is conducted with DWT by applying preprocessing, and the low-frequency wavelet coefficients are regarded as the perceptual feature value. Then the measurement matrix controlled by chaos map is applied to reduce the dimension of feature value. Finally, the feature value is used to generate the perceptual hash sequence by the process of hashing structure. The measurement matrix is designed as the secret key to enhance the security of the proposed algorithm. The experimental results demonstrates the proposed algorithm has high efficiency in perceptual robustness, discrimination, time consumption and security, as well as having a high accuracy of tampering detection and localization.

This work describes the preparation and catalytic performance of magnetic Janus quaternary ammonium phase transfer catalysts Fe3O4 & P(GMA-AA-DVB)N+(CH3)3OH− (MJPTCs). The morphologies, structures and other physical properties of the Janus catalysts prepared by a modified solvent thermal method were characterized by TEM, FTIR, TGA, VSM and XRD. The reaction of benzyl alcohol and benzyl bromide to generate dibenzyl ether was chosen as the model reaction to evaluate the catalytic activity of the MJPTCs. Besides, the influence of catalyst concentration and reaction temperature on catalytic efficiency was investigated in detail. The experimental results showed that the MJPTCs exhibited great catalytic activity with a conversion rate of 99% in only 2.5 h, and excellent reusability with a conversion rate of 97% after 8 cycles.

Both aminopropylisobutyl polyhedral oligomeric silsesquioxane (NH2-POSS) and hydrazine monohydrate were utilized to functionalize graphene oxide (GO), and to obtain chemically modified graphene (CMG), which was then used for preparing thermally conductive CMG/polyimide (CMG/PI) nanocomposites via a sequential in situ polymerization and electrospinning-hot press technology. NH2-POSS molecules were grafted on the GO surface, and CMG was obtained by the reaction between NH2-POSS and GO. The thermal conductivity coefficient (λ), glass transition temperature (Tg) and heat resistance index (THRI) of the prepared CMG/PI nanocomposites were all increased with increasing the CMG loading. The λ value of the CMG/PI nanocomposites with 5 wt% CMG was significantly improved to 1.05 W m−1 K−1, about 4 times higher than that of the pristine PI matrix (0.28 W m−1 K−1). The corresponding Tg and THRI values were also increased to 213.0 and 282.3 °C, respectively. Moreover, an improved thermal conductivity model was proposed and predicted the λ values of the nanocomposites more precisely than those obtained from the typical Maxwell, Russell and Bruggemen classical models.

In last few decades the demand of lipase has been dramatically increase due to its useful use in numbers of biochemical industries. Varieties of natural and synthetic carriers and methodologies have been used to improve lipase activities by the process of immobilization in order to enhance its activities in term of its resistance to high temperature, pH and to increase its reusibity and storage capacity. Due to the expensive nature the recycling of the lipase has been the target of the researchers to decrease its cost in the industrial process. Magnetic iron oxide organic/inorganic hybrid nanoparticles as a support have been mostly used in the lipase immobilization due its large surface area, less toxicity, bio compatibility, easily functionalization, separation avoiding long time consuming process like filtration and centrifuging.

A facile, robust, scalable and eco-friendly route as part of a relatively simple system to prepare polymer capsules has always been desired but remains challenging. Herein, a multifunctional, active, amphiphilic macromolecule, 1,1-diphenylethylene (DPE)-capped hydrolyzed poly(glycidyl methacrylate) (D-PGMA), was found to act as both the surfactant and the initiator in an interfacial emulsion polymerization process for polymer capsules. This simplified the emulsion system to only three components: water, monomer and D-PGMA. The interfacial distribution of amphiphilic D-PGMA and the controlled/living radical polymerization owing to the semi-quinoid structure were synergistically responsible for the formation of polymer capsules. Besides, by employing this method, microcapsules encapsulating phase change materials (PCMs) whose encapsulation ratio could be up to 92% were readily fabricated and possessed large heat storage capability and good thermal stability. We believe that this facile, robust, scalable and eco-friendly method will inspire new strategies for preparing polymeric capsules and will find promising application in the field of energy storage.

Monodisperse poly(glycidyl methacrylate)/polystyrene (PGMA/PS) anisotropic microspheres have been fabricated by seed polymerization. From the SEM images, it is known that the obtained PGMA/PS microspheres have three different morphologies: raspberry-shaped, golf-shaped and porous structures. Based on the successful fabrication of these micropheres, bovine serum albumin (BSA)-imprinted PGMA/PS microspheres were fabricated via dopamine auto-polymerization in alkaline solution. Because dopamine does not affect the validity of the protein structure, the imprinted cavity structure on the surface of the MIPs can match the template protein molecules completely. The obtained micron-sized BSA-imprinted PGMA/PS microspheres have an excellent saturation adsorption capacity (Q = 72.7 mg g−1) and good selective adsorption for BSA (IF = 4.6).

In this study, the Mg-Fe-LDH@biochar composite was firstly fabricated and applied for effectively activation peroxymonosulfate (PMS) for aqueous doxycycline (DOX) degradation. The physiochemical properties of the as-synthesized composite were thoroughly characterized. In the developed Mg-Fe-LDH@biochar/PMS system, the catalytic DOX degradations were evaluated under different conditions. Under the optimal condition (0.75 g/L catalyst loading, 0.75 g/L PMS dosage, pH = 7.0), about 88.76% DOX (35 mg/L) was removed within 120 mins. The results of quenching test and electron paramagnetic resonance (EPR) illustrated that the •OH, SO4•- and •O2– radicals all contributed to the DOX degradation in the Mg-Fe-LDH@biochar/PMS system, whereas the 1O2-based non-radical degradation played the dominant role in DOX removal. The developed system was almost not adversely affected by the high-strength anions and exhibited high DOX decomposition rates in a wide pH range from 3.0 to 9.0, indicating the great potential in the practical application. The satisfactory reusability of the composite catalyst was demonstrated in the recycling test, with the DOX removal efficiency slightly declined from 90.08 to 84.42% after five runs. Based on the generation of reactive oxidative species and the transformation intermediates identified by HPLC-MS, the possible degradation pathways and reaction mechanism of DOX degradation in Mg-Fe-LDH@biochar/PMS system were proposed.

Using MnO2 nanowires as a template and coating with polydopamine, the MoS2 nanosheets are uniformly grown on the surface and the core–shell structure MnO2@NC@MoS2 nanowires are obtained after annealing. By etching and removing the MnO2 nanowires template with acid solution, NC@MoS2 wave absorber with tubular hollow structure is obtained. The design of the core–shell structure, the growth of MoS2 nanosheets, the existence of heterogeneous interfaces and the construction of tubular hollow structures effectively enhance the microwave absorption performance of NC@MoS2. The minimum reflection loss (RLmin) is reduced and the Effective absorption bandwidth (EAB) is broadened. Finally, the NC@MoS2 nanotube absorber has a RLmin of −52.56 dB, and the EAB is 6.0 GHz. As an efficient lightweight microwave absorber, NC@MoS2 has potential value in the synthesis and application of new composite microwave absorbing materials.

The “glue + particles” approach has presented an excellent idea for promoting the practicability of superamiphiphobic surfaces. However, strong polar materials, such as epoxy and polyurethane, are usually employed as adhesives. The superamphiphobic behavior will be immediately lost when parts of superhydrophobic particles are removed. Thus, a glue with robust self-healing liquid-repellence is desirable, but remains challenging to realize. Herein, a robust, self-healable, superamphiphobic film was fabricated by a liquid-repellent “glue + particles” approach. The coating based on a sol-gel network showed exceptional liquid-repellency to low surface tension liquids including ethanol. The designed coating is based on robust sol-gel network dangling fluoroalkyl chains which integrates the bonding and self-healing mechanisms for providing a longer usage life. It could withstand at least 400 cycles of abrasion under severe stress (45 kPa), strong acid/base solution, hot-liquids and smudge treatment without apparently changing the superamphiphobicity. This novel and effective coating system may be useful for the development of robust protective clothing for various applications. Keywords: Superamphiphobic, Robust, Self-healable, Thiol-ene, Liquid-repellent glue

Superamphiphobic surfaces with a rapid ability to autorepair from multiple damages are desirable for long-lived self-cleaning coatings. Previous studies have almost introduced such a self-healing surface against chemical or physical damage, however, the regeneration is out of work as stain accumulates over time. Herein, a low-maintenance superamphiphobic coating based on a smart two-layer self-healing network has been presented. The coated fabric can withstand at least 200 cycles of abrasion under a pressure of 45 kPa and strongly resist to UV radiation, boiling treatment, strong acid/base immersion and smudge treatment, without apparently changing the superamphiphobicity. Besides physical and chemical damages, the coating can even rapidly retain its super liquid-repellence against a long-term accumulation of smudge by using a short heating treatment. Such a rapid and multiple self-healing ability resulting from the smart two-layer network may be useful for the development of low-maintenance protective coatings.

Overcoming multidrug-resistant (MDR) bacterial infection and simultaneously enhancing wound healing/skin reconstruction are still critical challenges for both clinic practice and fundamental research. The single modal therapy strategy is usually inefficient. Herein, for the first time, multifunctional MXene@CeO2 nanocomposites were prepared by combining the 2D antibacterial conductive Ti3C2Tx MXenes and antioxidant CeO2 and applied in developing multifunctional hydrogel scaffold (FOM) for MDR infection-impaired skin multimodal therapy. FOM scaffold was fabricated by incorporating MXene@CeO2 nanocomposites in a dynamic Schiff-based chemical crosslinked hydrogel of polyethylenimine grafted Pluronic F127 (F127-PEI) and oxidized sodium alginate (OSA). FOM scaffold possessed multifunctional properties including injectable self-healing behavior, efficient anti-inflammatory, antibacterial, and antioxidative abilities, conductive bioactivities, tissue-adhesive ability and fast hemostatic capacity. FOM scaffold could promote fibroblasts migration and cell proliferation with electrical stimulation. Additionally, FOM scaffold demonstrated the significant anti-inflammatory and multidrug resistant infection therapy, meanwhile promoting fibroblasts proliferation, granulation tissue formation, collagen deposition, re-epithelialization to accelerate MDR-infected wound healing. This work firstly demonstrated the important role of multifunctional MXene@CeO2 nanocomposites in infected-wound healing/skin reconstruction. This study provided an efficient multimodal therapy on MDR infection-impaired skin via the optimization of the structure and multifunctional properties of biomaterials.

Emerging as an innovative class of polymeric material, vitrimers possess the advantages of thermoplastics as well as thermosets and of great interest due to its ability to reduce environmental pollution and waste of resources caused by plastic abuse. In the present work, we prepared a series of carbon nanotube-vitrimer composites (EPCNTx) containing double dynamic covalent bonds (carboxylate and disulfide bonds), of which EPCNT5 (the MWCNTs content is 5 wt%) displayed the best electrical conductivity (1.63 S/m) and good mechanical properties (tensile stress = 16.3 MPa, fracture strain = 81.8%). Additionally, EPCNT5 has the advantages of vitrimer, i.e., reprocessability, degradability, and photo-welding performance, fully combining the advantages of vitrimer and epoxy composites. Furthermore, the EPCNT5 is fabricated as a skin sensor, demonstrating its potential application in the field of skin sensing.

Transition metal carbide (MXene) has attracted much attention due to its special structure and surface chemical properties. However, like other two-dimensional (2D) materials, its application is severely affected by stacking and agglomeration. Herein, we construct intertwined one-dimensional (1D) heterostructure via the assembly of MXene and metal–organic frameworks (MOFs) without any assistance of template and rigid framework. The results have shown that by manipulating the loading of MOFs on 1D MXene fibers, the growth of CNTs can be effectively controlled, thereby realizing the regulation of electromagnetic parameters. The 3D cross-linked network constructed by intertwined 1D heterogeneous components (MXene fibers/CoNi/C and CNTs/CoNi) features extensive heterogeneous interfaces, hierarchical pore structure and desirable conductivity, exhibiting superior microwave absorbing properties. Notably, under a matching thickness of 1.6 mm, the minimum reflection loss (RLmin) of the absorber (MMC) exceeds −51.6 dB, and the effective absorption bandwidth (EAB, RL

With the development of protein imprinting technique, the certification about the existence of imprinted sites, the arrival of template molecules and target molecules into the same cavity, and the specific separation process based on imprinted sites have seldom been studied so far. To promote the development in the field of protein imprinting, a method for proving the existence of the imprinting sites based on the fluorescence signal changes of the fluorescent materials labeling at the imprinted sites is first proposed in this work. Simultaneously, a novel protein imprinted material with ability of binding signal transduction is developed. The core of the imprinted materials is that bovine serum albumin (BSA) modified by a designed and synthesized functional monomer containing a polymerizable double bond and a cleavable dynamic disulfide bond is selected as a template. And the imprinted polymers supported on the surface of the tubular carbon nanofibers are constructed by thermally initiated polymerization. Fluorescein 4-(N, N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) is used to label the sulfhydryl groups generated by the cleavage of disulfide bonds at the imprinting sites. The identification of the imprinting sites is achieved by the change in the fluorescent signal generated when BSA is recombined to the imprinting sites. The results of fluorescence detection and adsorption experiments show that the imprinting sites exhibit specific binding and excellent reusability for BSA. In addition, another fluorescein N-(9-acridinyl) maleimide is utilized to label the imprinting sites, which produced a similar fluorescence signal response. Therefore, the experimental results are verified.

For reinforced concrete (RC) structures in coastal regions, fatigue loading is a common loading type, which has the potential to progressively promote micro-cracks generation and development, and in turn, greatly to facilitate the water and aggressive agents (such as chloride and sulfate ions, which are usually sucked by water) penetration in concrete. Therefore, it is imperative to investigate the behavior of water movement in concrete after fatigue loading. This paper presented an experimental investigation on the influence of fatigue stress level and loading cycles, which may induce different degree of damage for concrete, on the transport rate and volume of water absorbed by concrete after compressive fatigue loading. The residual strain was measured by strain gauges to represent the damage evolution of concrete and estimate the water absorption in concrete under cyclic loading. Moreover, the cumulative water content of specimens under fatigue loading was recorded in real time through an improved test apparatus. The results show that the residual strain and cumulative water content of concrete increase with the increase of stress level and loading cycles. The initial and secondary sorptivities, i.e., the slope of the two linear parts of the cumulative water content-time1/2 curves, both increase dramatically when stress level and loading cycles increase because of the development of the cumulative pore volume in concrete corresponding to various pore radius. In addition, a theoretical model for predicting water absorption of concrete damaged by compressive fatigue loading was developed in terms of the residual strain, which shows good agreement with experimental data.

In order to solve hashing sequences leakage in the existing speech authentication algorithms, this paper proposed a speech biohashing authentication based on power spectrum. Fristly, the algorithm pre-processed the original speech, then used the improved covariance method to extract the power spectrum feature of the speech, and generated a one-dimensional feature vector from the feature matrix. A pseudo-random matrix was generated by using Sinc function transform, the feature vector and pseudo-random matrix are projected and mapped to construct the biometric template. Finally, binarization process was used to generate hash index, and upload it to the cloud. The experimental results show that the algorithm has good discrimination, robustness and authentication performance. At the same time, the biometric template has good security and ensures the irreversibility of the hashing sequence.

Rapid self-healing of micro-configurations is an effective strategy to enhance the durability of superhydrophobic surfaces, however, this property is challenging to achieve. Here, a durable superhydrophobic coating with a precisely targeted self-healing ability to repair its’ dual structure was developed by spray-coating a polyimine film with a mixture of novel fluorinated epoxy resin and Fe3O4@SiO2–NH2 nanoparticles. The superhydrophobic surface can heal both the broken morphology and wettability through a short irradiation process on account of its local photothermal conversion ability and dynamic imine bond, and can maintain the static water contact angle at a value higher than 159° even after six damage/healing cycles. Furthermore, superhydrophobic coatings can be controllably degraded in three ways. Additionally, because of the robust epoxy resin protection, the surface can withstand sixteen times the dynamic impact and still maintain a WCA greater than 150°. This preparation strategy may aid the fabrication of durable superhydrophobic surfaces for various practical applications.

Bimetallic MOFs with core–shell morphology are prepared by feeding step by step. Sandwich type ZIF-67@ZIF-8@TiO2 is prepared by coating TiO2 shell layer on the surface of the obtained ZIF-67@ZIF-8 via hydrolysis technology. After pyrolysis of ZIF-67@ZIF-8@TiO2, ZnCo/NC@TiO2 composite wave absorber with yolk-shell structure is fabricated. The evaporation of zinc, volatilization of organic components and shrinkage of carbon layer at high temperature result in a larger cavity between the core and shell. Large specific surface area, pore volume and cavity structure are favorable for multiple interface reflection. Existence of multiple heterogeneous interfaces, unevenly distribution of space charges accumulated between the interfaces, abundant crystal defects and doped atoms lead to the continuous occurrence of interface/dipole polarization. These make the absorber exhibits excellent microwave absorption performance. The study shows that under the optimum carbonization temperature (700 ℃) and filler content (37%), minimum reflection loss (RLmin) of ZnCo/NC@TiO2 reaches −46.21 dB@9.5 GHz with a matching thickness of 2.8 mm. Meanwhile, by adjusting the thickness of absorber, the effective bandwidth can cover 4.3–18 GHz. Maximum effective absorption bandwidth is up to 4.5 GHz. This work will provide a new strategy for the effective construction of yolk-shell microwave absorbing materials derived from bimetallic MOFs as well as performance optimization of existing microwave absorbing materials.