查找使用阿拉丁产品的科研文献

Equivalent Circuit Models for Magnetoelastic Resonance Sensors With Various Surface Loadings

Yao Lu,Hongxiang Zhang,Jun Qian,Yu Song,Bidou Wang,Haixuan Sun

Smart polymer with rapid self-healing and early corrosion reporting capabilities: Design, performance and mechanism

Hao Jiang,Zhikun Wang,Meng Cheng,Wuting Pang,Yizeng Mou,Fanjie Meng,Chunling Li,Shuangqing Sun,Songqing Hu,Zhigang Di,Bingjie Lian

Organic coatings have great anti-corrosion performance, but they cannot exert timely repair to the damaged region and detect the early corrosion of the steel. Here, we prepared a smart anti-corrosion polymer (PU-Phen) which is capable of efficient self-healing and early corrosion reporting. When the damaged PU-Phen polymer and its coating was allowed to heal at 60 °C for 3 h, the healed polymer exhibits the high self-healing efficiency in terms of mechanical property of 89.3 % and a satisfactory recovery of anti-corrosion property. Through in-depth analysis of the experimental results and molecular dynamics (MD) simulations data of the self-healing process, the self-healing process is attributed to the regeneration of H-bonds and van der Waals (vdW) interactions, which not only promotes the molecular fusion to achieve the microscopic self-healing process, but also cooperates with the molecular conformational restoration to promote macroscopic elastic recovery. In addition, MD simulations of the self-healing process and rheological experiments at different temperatures also indicated that high temperature have a positive effect on self-healing process by promoting molecular movement and regeneration of H-bonds and vdW interactions. In addition, experimental results indicate PU-Phen coating can timely exhibit red color to report the early corrosion of steel based on formation of the chelate between phenanthroline (Phen) and Fe 2+ . This work provides a general strategy for engineering smart coatings and may deepen the mechanism research of other self-healing polymers.

Ultrasonic-assisted synthesis of porous S-doped carbon nitride ribbons for photocatalytic reduction of CO2

Jiabei Wang,Zhiqiang Jiang

A series of porous S-doped carbon nitride ribbons (PSCN) were prepared by one-pot hydrothermal and sonochemical synthesis techniques. The morphologies and nanostructures of the catalysts were characterized by SEM, XRD and IR, which confirmed the pristine graphitic structures of carbon nitrides retained in the products. Due to sonication treatment, PSCN has porous structures in the thin ribbon and larger specific surface areas (PSCN 43.5 m 2 /g, SCN 26.6 m 2 /g and GCN 6.5 m 2 /g). XPS and elemental mappings verified that sulfur atoms were successfully introduced into the carbon nitride framework. Diffuse reflectance spectroscopy (DRS) results showed S-doping in the carbon nitride reduced the bandgap energy and enhanced their capability of the utilization of visible light, which contributed to higher photo-generated current. Photoluminescence (PL) analysis indicates the recombination of photogenerated carriers was suppressed in PSCN. Moreover, the photocatalytic performance showed that S-doping and porous and thin ribbon nanostructures may effectively boost the CO 2 reduction rate (to as much as 5.8 times of GCN) when illuminated by   visible light (>420 nm) without the need of sacrificial materials. The preliminary mechanisms of the formation of PSCN and its applications in photocatalytic CO 2 reduction are proposed. It highlights the potential of the current technique to produce effective, nonmetal-doped carbon nitride photocatalysts.

Thermal-Sinterable EGaIn Nanoparticle Inks for Highly Deformable Bioelectrode Arrays

Yan Niu,Gongwei Tian,Cuiyuan Liang,Tianchi Wang,Xu Ma,Guifen Gong,Dianpeng Qi

Liquid metal (especially eutectic gallium indium, EGaIn) nanoparticle inks overcome the poor wettability of high surface tension EGaIn to elastomer substrates and show great potential in soft electronics. Normally, a sintering strategy is required to break the oxide shells of the EGaIn nanoparticles (EGaIn NPs) to achieve conductive paths. Herein, for the first time, thermal-sinterable EGaIn NP inks are prepared by introducing thermal expansion microspheres (TEMs) into EGaIn NP solution. Through the mechanical pressure induced by the expansion of the heated TEMs, the printed EGaIn NPs can be sintered into electrically conductive paths to achieve highly stretchable bioelectrode arrays, which exhibit giant electromechanical performance (up to 680% strain), good cyclic stability (over 2 × 10 4 cycles), and stable conductivity after high-speed rotation (6000 rpm). Simultaneously, the recording sites are hermetically sealed by ionic elastomer layers, ensuring the complete leakage-free property of EGaIn and reducing the electrochemical impedance of the electrodes (891.16 Ω at 1 kHz). The bioelectrode is successfully applied to monitor dynamic electromyographic signals. The sintering strategy overcomes the disadvantages of the traditional sintering strategies, such as leakage of EGaIn, reformation of large EGaIn droplets, and low throughput, which promotes the application of EGaIn in soft electronics.

MWCNTs wrapped in hollow with open holes of CoFe2O4 as high-performance electromagnetic wave absorbers

Danqiang Huang,Jianfeng Dai,Qing Wang,Hui Liu,Zengpeng Li

A multi-component, special structure of electromagnetic wave absorber produces significant electromagnetic wave absorption performance because of excellent impedance matching. In this work, CoFe 2 O 4 @CNTs composites are prepared. CoFe 2 O 4 exhibits a hollow and open-hole shape with a rough surface, and this structure facilitates more electromagnetic wave absorption. The incorporation of multiwalled carbon nanotubes (MWCNTs) leads to dipole polarization and when wrapped around CoFe 2 O 4 particles, increases the interface loss. The influence of the filler-loading ratio on the microwave absorption performance of wax-based absorbers is thoroughly investigated. The highest electromagnetic wave absorption performance is obtained at 25% filling with a minimum reflection loss (RL min ) of − 36.52 dB at a thickness of 1.9 mm and effective absorption bandwidth (EAB) is 3 GHz. In this study, a method is proposed for creating high-performance electromagnetic wave absorbers.

Stretchable, conductive and anti-freezing poly (vinyl alcohol)-based organo-hydrogels for strain sensors

Guoqiang Lu,Chao Li,Guohua Wang,Jun Nie,Xiaoqun Zhu

Conductive hydrogels have drawn significant attention in the field of stretchable sensors. However, the freezing and drying of water, the introduction of additional ions and ions leakage made the preparation process relatively complicated and significantly limited their long-term stability and safety. In this work, Poly (vinyl alcohol) – based organo-hydrogels were fabricated via photodimerization and freezing-thawing (F-T) cycles of the mixed solution of Polyvinyl alcohol bearing styrylpyridinium group (PVA-SBQ) and Poly (vinyl alcohol) (PVA). The as-prepared PVA-SBQ/PVA organo-hydrogels possessed good stretchability (389%), facture strength (0.39 MPa), conductivity (3.1 *10 −4 S/cm at 25 ℃ and 4 *10 −5 S/cm at −30 ℃) and temperature tolerance (−30 ℃). And the organo-hydrogels displayed a gauge factor of 1.6 at a strain of 100% and a low degree of hysteresis (5.34% at 100% strain). In addition, the as-prepared organo-hydrogels exhibited good low temperature sensing performance, which could monitor strain at − 30 ℃, making the organo-hydrogel suitable for use in the field of strain sensors. Therefore, it is believed that the PVA-SBQ/PVA organo-hydrogels offer a promising prospect for practical applications.

Investigation of Oil–Water Separation on an F-SiO2/TiO2-Based Superhydrophobic/Superoleophilic Surface: Experiment Evaluation and MD Simulation

Chen Li,Yan Xiong,Lei Zhao,Haiqin Wan,Jun Li,Shenwen Fang,Meng Wang,Ming Duan,Jintian Ren,Yi Xiao

Experiment evaluation and mechanism analysis of separation performance are crucial for oily wastewater treatment. In this work, a fluorinated superhydrophobic/superoleophilic (F-SHPB/SOPL) surface was fabricated on a steel mesh substrate by double depositions of SiO2–TiO2 nanoparticles for high-roughness improvement and composite modification of fluorine-alkyl groups for low-energy achievement. Measurements of SEM, XPS, FTIR, laser scanning confocal microscope (LSCM), and excitation–emission matrix (EEM) were carried out for surface property characterization. The oil–water separation performances at the prepared F-SHPB/SOPL surface were investigated from experimental and simulation aspects. Separation tests, flux tests, and anti-contamination tests were performed by experimental methods. The results indicated that the surface showed excellent separation efficiencies (>99.2%) for oil–water mixture and oil-in-water emulsion, high permeate flux (>3000 L·m–2·h–1) for organic oils, and perfect anti-pollution/self-cleaning capacity for liquid and solid contaminations. The interaction energies and interaction distances were measured by ab initio molecular dynamics simulation (AIMD) simulations. With lower interaction energy (Eoil = −456.52∼−1044.22 eV) than that of water molecules (Ewater = −172.73 eV) and shorter distance (Doil = 4.42∼5.13 Å) than that of water molecules (Dwater = 11.49 Å), oil molecules showed higher interaction stability than water molecules on the F-SHPB/SOPL surface. The calculation revealed the essence of the oil–water separation phenomenon. This work not only proposes the fabrication methodology of the SHPB/SOPL material but also elucidates the intermolecular interaction for oil–water separation. The results can provide a fundamental basis for separation operation and removal treatment in industrial and domestic applications.

Chemical Compositions, Extraction Optimizations, and In Vitro Bioactivities of Flavonoids from Perilla Leaves (Perillae folium) by Microwave-Assisted Natural Deep Eutectic Solvents

Xianchao Shang,Manman Zhang,Jing Hu,Yuqin Zhang,Long Yang,Xin Hou

Natural deep eutectic solvents (NADESs) have been gradually applied to green extraction of active ingredients. In this study, microwave-assisted NADESs were applied to the extraction of flavonoid compounds from perilla leaves. Through comparative experiments, NADES-3 (choline chloride and malic acid at a molar ratio of 1:1) was found to have the highest extraction efficiency of total flavonoids, including apigenin 7-O-caffeoylglucoside, scutellarein 7-O-diglucuronide, luteolin 7-O-diglucuronide, and scutellarein 7-O-glucuronide by HPLC-MS. The following optimal extraction parameters were obtained based on response surface design: water content in NADES of 23%, extraction power of 410 W, extraction time of 31 min, and solid–liquid ratio of 75 mg/mL, leading to the extraction yield of total flavonoids of 72.54 mg/g. Additionally, the strong antimicrobial and antiallergic activity, inhibition of nitrosation, and antioxidant activity of total flavonoids by using NADESs were confirmed. This new extraction method provides a reference for the further exploration of NADES systems and may be widely used for the green extraction of natural active ingredients.Keywords:Perillae folium;natural deep eutectic solvents;microwave-assisted extraction;chemical compositions;antimicrobial activity;response surface methodology

A solar-driven self-repairing sponge for efficient recovery of crude oil

Changyuan Song,Yin Jin,Xiangyi Gu,Jianwei Shi

Solar-heated absorption has become an effective technique to handle the crisis of crude oil spill. Although photothermal absorbents could efficiently clean up crude oil in situ, oil recovery methods such as squeezing absorbents have a negative impact on structural integrity and performance of absorbents, shortening the service life of the device. Herein, a solar-driven carbon-doped self-repairing polyurethane sponge (CSPU) is fabricated for absorption and recovery of crude oil. Chitosan-derived N-doped porous carbon (NPC) as photothermal filler and 2-hydroxyethyl disulfide (HDES) as chain extender are introduced into sponge in situ through free foaming. The firm load of NPC endows CSPU with good light absorption of 97.1% and a stable photothermal conversion performance. Additionally, the solar-driven self-repairing property promotes CSPU to timely repair the structural damage caused in oil recovery process. Consequently, CSPU exhibits a high crude oil absorption of 23.5 g/g, and it still maintains a good oil absorption and recovery efficiency after friction, ultrasonic treatment or multiple absorption-recovery cycles. This strategy combining photothermal oil absorption and solar-driven self-repairing provides a sustainable and durable solution for addressing crude oil spills.

Preparation of the amorphous embolic agents from glyceryl triallyl ether via a photo-driven radical-mediated [3 + 2] cyclopolymerization

Lin Lingyin,Zhou Yanfang,Chen Piaoyi,Xiao Qinglin,Ye Guodong

Transcatheter arterial embolization is an established treatment for hepatocellular carcinoma (HCC). However, the existing embolic materials still have some shortcomings, e.g., particle clumping can cause catheter occlusion. In this study, after the synthesis of monomer glyceryl triallyl ether monomer (GE), amorphous embolic agent (PGE) was synthesized by photopolymerization in the presence of GE and photoinitiator. Combined with RT-IR, TG and GPC, we verified that the polymerization followed a photo-driven radical-mediated [3 + 2] cyclopolymerization mechanism (PRMC) through experimental and modeled NMR. The macromolecular properties such as polymerization profile and morphology were studied by TG and SEM–EDS. Finally, the degradation, swelling and migration behavior of PGE were characterized, which indicated that PGE could embolize HCC by blocking the blood supply. In this study, PRMC prevented GE polymerization from degradative chain transfer with 70% yield in an hour, and 200–350 µm PGE was synthesized using this mechanism suitable for clinical use. Graphical abstract

Multiphase Molybdenum Carbide Doped Carbon Hollow Sphere Engineering: The Superiority of Unique Double-Shell Structure in Microwave Absorption

Tianbao Zhao,Zirui Jia,Yan Zhang,Guanglei Wu

In order to achieve excellent electromagnetic wave (EMW) absorption properties, the microstructure design and component control of the absorber are critical. In this study, three different structures made of Mo 2 C/C hollow spheres are prepared and their microwave absorption behavior is investigated. The Mo 2 C/C double-shell hollow spheres consisting of an outer thin shell and an inner rough thick shell with multiple EMW loss mechanisms exhibit good microwave absorption properties. In order to further improve the microwave absorption properties, MoC 1-x /C double-shell hollow spheres with different crystalline phases of molybdenum carbide are prepared to further optimize the EMW loss capability of the materials. Finally, MoC 1-x /C double-shell hollow spheres with α-phase molybdenum carbide have the best microwave absorption properties. When the filling is 20 wt.%, the minimum reflection loss at 1.8 mm is −50.55 dB and the effective absorption bandwidth at 2 mm is 5.36 GHz, which is expected to be a microwave absorber with the characteristics of “thin, light, wide, and strong”.

Influence of Gelatin-Chitosan-Glycerol Edible Coating Incorporated with Chlorogenic Acid, Gallic Acid, and Resveratrol on the Preservation of Fresh Beef

Jinhao Zou,Xueming Liu,Xuping Wang,Huaigu Yang,Jingrong Cheng,Yaosheng Lin,Daobang Tang

Chlorogenic acid (CA), gallic acid (GA), and resveratrol (RES) were added to a gelatin (GEL)-chitosan (CHI)-glycerol (GLY) edible coating, and their effects on the coating of fresh beef preservation were investigated. The results revealed that CA had the most significant improvement effect on fresh beef preservation. The combination of GEL-CHI-GLY-CA preserved the color of the beef better and delayed the increase of the total volatile base nitrogen, even though its total phenolic content decreased at a faster rate during beef preservation. GA also improved the preservation effect as on the 12th day of storage, the beef samples treated with GEL-CHI-GLY-GA had the lowest thiobarbituric acid reactive substances (0.76 mg Malondialdehyde (MDA)/kg) and total viable count (6.0 log cfu/g). On the whole, though RES showed an improvement on beef preservation, the improvement was not as good as the other two polyphenols. After 12 days of storage, the beef samples treated with GEL-CHI-GLY-RES had a higher pH value (6.25) than the other two polyphenol treatmed groups. Overall, the three polyphenol-added combinations increased the shelf life of beef by approximately 3–6 days compared to the control group (treated GEL-CHI-GLY with distilled water).Keywords:fresh beef;edible coating;polyphenols;meat quality