Acta Metallurgica Sinica-English Letters
·
2021
·Vol. 35
·期 3
·411-424
·
IF 2.755
Xu Rong,Li Ruidi,Yuan Tiechui,Zhu Hongbin,Li Ping
In order to refine the microstructure and improve the performance of direct energy deposited (DED) additively manufactured Al–Mg–Sc–Zr alloy, TiC-modified Al–Mg–Sc–Zr composites were prepared by DED and the effect of TiC content on the microstructure and performance was studied. In the absence of TiC particle, the microstructure of Al–Mg–Sc–Zr alloy prepared by DED consisted of fine grains with average size of 8.36 μm, and well-dispersed nano-Al 3 (Sc,Zr) particles inside the grains and Mg 2 Si phase along the grain boundaries. With the addition of 1 wt% TiC, the microstructure of TiC/Al–Mg–Sc–Zr prepared by DED became finer apparently compared with that without TiC; while the further increase of TiC content to 3 wt%, the microstructure of TiC/Al–Mg–Sc–Zr prepared by DED became coarser with appearance of a new kind of needle-like (Ti,Zr) 5 Si 3 phase. Also, the addition of TiC decreased the porosity of Al–Mg–Sc–Zr prepared by DED. Simultaneously, after the addition of TiC, the tensile strength increased from 283.25 MPa to 344.98–361.51 MPa, and the elongation increased from 3.61% to 9.58–14.10%. The potential mechanism of the microstructure evolution and strength improvement was discussed. This research will provide new insights into the available metal matrix composites by laser additive manufacturing (LAM).
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 13
·7447-7461
·
IF 4.21
Zhang Caihong,Wu Min,Yang Shuang,Song Xueping,Xu Ying
Abstract The low yield and size nonuniformity of cellulose nanofibrils (CNFs) prepared by mechanical grinding restrict their extensive application in many fields. In this study, microfibrillated cellulose (MFC) with varying grinding time (0–2.5 h) was post-treated with endoglucanase (EG) to improve the yield and size uniformity of the CNFs. With the same grinding time, the yield of the CNFs post-treated with EG increased approximately one-fold, and the diameter of the microfibrils decreased according to the SEM and TEM images. The yield of the CNFs ground for 0.5 h and post-treated by EG was similar to that of the sample ground for 2.5 h, and approximately 26.1 kWh/kg mechanical grinding energy were saved by the EG post-treatment while obtaining the same CNF yield. There was an abundance of micropores that affected the specific surface area of samples, and the width of the micropores was centered between 1.3 and 2.0 nm. The crystallinity index (CrI) of the MFC decreased gradually from 74.90 to 69.30% with prolonged grinding time, whereas the CrI of the samples post-treated by EG slightly increased between 1.7 and 3.0%. The tensile strength and elongation at break of the films prepared by the EG post-treated samples slightly decreased, while the Young’s modulus and transmittance increased. This study provides a valid and an eco-friendly biological method to improve the yield and size uniformity of CNFs and reduce energy consumption. Graphic abstract
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 7
·3789-3804
·
IF 4.21
Xu Wenlong,Xin Binjie,Yang Xue
Polyacrylonitrile (PAN)/cellulose nanofibril (CNF) based carbon nanofiber membranes were produced by electrospinning and carbonization method, in which the CNF amount was 1 wt%. In order to control the spinning process, the rheological properties of the PAN/CNF suspensions were measured before electrospinning. In addition, the effects of CNF particle size on the structure and properties of carbon nanofiber membranes were investigated systematically by SEM, FTIR and mechanical test. Meanwhile, the reaction mechanism of PAN and PAN/CNF nanofiber membranes in the process of stabilization and carbonization was also fully discussed. The results show that the addition of CNFs can improve the breaking strength and conductivity of PAN carbon nanofiber membrane. Moreover, CNFs also can accelerate the carbonization rate and reduce the reaction conditions of PAN nanofiber membranes. Therefore, CNFs are effective enhancers for PAN based carbon nanofiber membranes.
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 15
·8667-8679
·
IF 4.21
Hou De-Fa,Tan Huang,Li Meng-Lei,Tang Yue,Liu Zheng-Ying,Yang Wei,Yang Ming-Bo
Due to the fact that natural cellulose cannot be melted, it is still challenging to process this biopolymer via thermoplastic processing methods. Herein, polycaprolactone diol was grafted onto regenerated cellulose (RC) via hydroxyl/isocyanate chemistry in dimethyl sulfoxide to endow cellulose with thermoplasticity. By adjusting the reaction parameters including the feeding ratios of reactants and reaction time, several homogeneous cellulose grafted polyurethanes (RC-g-PU) with the degree of substitution (DS) ranging from 0.49 to 1.48 and degree of polymerization ranging from 1.84 to 3.3 were synthesized. The thermoplasticity of the obtained RC-g-PU was well characterized by differential scanning calorimetry and optical microscope. The results revealed that the prepared RC-g-PU with DS values ranging from 1.01 to 1.48 can be melted at above 168.4 °C because PU side chains can serve as internal plasticizers and prevent the restacking of cellulose chains. Eventually, the synthesized thermoplastic RC-g-PU can be processed into transparent films by hot-pressing at 170 °C. Therefore, this research constructs a melt-processable cellulose derivative by a simple and engineering method.
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高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 140
·期 4
·1791-1800
·
IF 2.471
Wang Xuan,Xiao Kesong,Liu Xiangnong,Wu Hao,Gao Cai
The phenomenological models based on fictive temperature and nonlinear Adam–Gibbs formulation have been widely used to describe the enthalpy relaxation kinetics. Although the parameters in Adam–Gibbs formulation are physically explicable, the reasonabilities of the parameters obtained from curve-fitting procedures have not been systematically discussed yet. In this work, differential scanning calorimetry was employed to measure the heat capacities of maltitol in both the amorphous and the crystalline states, and the data were used to generate the model parameters. Results showed that the configurational ground state plays an important role in extracting the model parameters. Selecting the crystal rather than the glass as the ground state seems to be effective to improve the reasonabilities of the fitted parameters. It suggested that even if the fit quality seems sound, the physical reasonability of the best-fit parameters still needs to be treated with caution.
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高影响因子
Science China-Materials
·
2019
·Vol. 63
·期 2
·258-266
·
IF 5.636
Ma Bo,Zhao Jinping,Ge Zhenhua,Chen Yantao,Yuan Zhihao
Graphitic carbon nitride (g-C 3 N 4 ) coupled with NiCoP nanoparticles with sizes around 5 nm have been fabricated via a controllable alcohothermal process. NiCoP is an excellent electron conductor and cocatalyst in photocatalytic reactions. The coupling between tiny NiCoP nanoparticles and g-C 3 N 4 through in-situ fabrication strategy could be a promising way to eliminate the light screening effect, hinder the recombination of photo-induced charge carriers, and improve the charge transfer. The NiCoP/g-C 3 N 4 nanohybrids exhibit an excellent photocatalytic activity in the hydrogen generation, with a significantly improved performance compared with original g-C 3 N 4 , CoP/g-C 3 N 4 and Ni 2 P/g-C 3 N 4 , respectively. This study paves a new way to design transition metal phosphides-based photocatalysts for hydrogen production.
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高影响因子
Nano Research
·
2024
·
IF 9.5
Ji Ting,Deng Quanzheng,Chen Hao,Han Lu,Qu Zhibei,Che Shunai,Duan Yingying
Spin chiral anisotropy (SChA) refers to the occurrence of different spin polarization in antipodal chiral structures. Herein, we report the SChA in diamagnetic chiral mesostructured In 2 O 3 films (CMIFs) with manifestation of chirality-dependent magnetic circular dichroism (MCD) signals. CMIFs were grown on fluorine-doped tin dioxide conductive glass (FTO) substrates, which were synthesized via a hydrothermal route, with malic acid used as the symmetry-breaking agent. Two levels of chirality have been identified in CMIFs: primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes. CMIFs exhibit chirality-dependent asymmetric MCD signals due to the different interactions of chirality-induced effective magnetic field and external magnetic field, which distinguish from the commonly observed external magnetic fielddependent symmetric MCD signals. These findings provide insights into spin manipulation of spin-paired diamagnets.
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高影响因子
IONICS
·
2022
·Vol. 28
·期 12
·5341-5350
·
IF 2.961
Wang Lei,Yan Jiawei,Shen Wenzhuo,Zhong Min,Zhang Jiali,Guo Shouwu
Poly(ethylene oxide) (PEO)-based polymeric solid electrolytes (PSEs) hold great promise for all-solid-state lithium batteries, but the intrinsic low mechanical strength of PEO limits their practical application and scale production. Herein, PSEs consisting of PEO and lithium bis(trifluoromethanesulfonyl)-imide (LiTFSI) supported on poly(hexamethylene adipamide) (nylon) nanofiber matrix (nylon@PEO/LiTFSI PSEs) are designed and prepared in situ on the Al, Cu foils, and the LiFePO 4 electrodes through coaxially electrospinning at 45 °C. The nylon@PEO/LiTFSI PSEs show nonporous morphology due to in situ melting of the PEO/LiTFSI shell. The mechanical strength of the nylon@PEO/LiTFSI PSE can reach to 3.32 and 2.44 MPa at 25 and 60 °C, respectively, which is stronger than that of the pure PEO membrane or the PSEs prepared via conventional solution casting. The nylon@PEO/LiTFSI PSEs also show tight interfacial contact with LiFePO 4 electrode, resulting in small charge transfer resistance of 376 Ω, and thus afford the LiFePO 4 half coin cells with long charge/discharge cycling stability.
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高影响因子
POLYMER JOURNAL
·
2022
·Vol. 54
·期 11
·1383-1389
·
IF 3.135
Wang Jiacheng,Ye Tingting,Li Yiran,Wang Lie,Li Luhe,Li Fangyan,He Er,Zhang Ye
Fiber batteries have been developed as ideal energy storage devices for wearable electronics due to their superior miniaturization, deformability, and flexibility compared with conventional bulk and thin-film batteries. However, currently reported fiber batteries use materials that are intrinsically rigid or have limited flexibility (e.g., metal, carbon materials, and elastomers), which potentially cause physical irritation and internal injury upon close contact with biological tissues. Therefore, it is necessary to design soft materials for ultrasoft fiber batteries that are mechanically matched with biological tissues. Here, ultrasoft coaxial fiber-structured aqueous lithium-ion batteries based on an all-hydrogel design are reported. The all-hydrogel fiber aqueous lithium-ion batteries exhibited a low Young’s modulus of 445 kPa, which perfectly matched that of biological tissue. They also showed a high specific discharge capacity of 84.8 mAh·g −1 at a current density of 0.5 A·g −1 and superior performance in terms of cycling behavior and rate capacity. Furthermore, these fiber batteries maintained stable electrochemical performance while undergoing different complex deformations. The present work demonstrates a paradigm for designing ultrasoft fiber batteries and also provides insight into the development of soft wearable electronics.
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 7
·1841-1848
·
IF 2.482
Wu Ting-Ting,Zhao Xiang-Jie,Yang Rong-Ling,Bilal Muhammad,Wang Zhao-Yu,Luo Hong-Zhen,Xu Ning-Ning,Nie Ze-Kun
In this study, lyophilized Pseudomonas aeruginosa based whole-cell biocatalyst was used in the highly efficient and regioselective acylation of helicid with fatty acid vinyl esters in organic solvents. P. aeruginosa whole-cell catalyst showed high biomass and biocatalytic performance using 0.1% (w/v) soybean oil and 0.2% (w/v) tryptone as the carbon and nitrogen source, respectively. The biomass (0.72 g/L) cultivated for 36 h under the optimized conditions was 2-folds higher than that obtained by the use of the initial conditions (0.36 g/L). In addition, the optimized medium was found to be suitable for P. aeruginosa cultured in 3.5-L scale fermentation with high biomass (0.71 g/L) obtained at 24 h. Besides, a high substrate conversion efficiency (ranged from 92 to 99%) and excellent regioselectivity (99%) was achieved when P. aeruginosa whole-cell biocatalyst was applied to synthesize an array of 6′-esters of helicid. The reaction rate varies with varying acyl donors because of their differential interactions with the catalytic site of the enzyme from the whole cells of P. aeruginosa . Taken together, P. aeruginosa whole-cell catalyst obtained using optimal culture medium manifest a promising and highly-regioselective alternative to purified enzymes for the regioselective formation of 6′-esters derivatives of helicid in non-aqueous solvents. Graphic Abstract
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高影响因子
JOURNAL OF POLYMER RESEARCH
·
2024
·Vol. 31
·期 4
·1-12
·
IF 2.6
Liu Yunhe,Fang Xiya,Feng Zongze,Zhang Xiaotao,Wang Honggen,Shi Yan
Herein, we developed a reversible complexation mediated polymerization (RCMP) starting with a complex of iodine and organic salt as a deactivator and a thermal initiator for continuous regeneration of the organic salt activator. This novel polymerization method can be called as initiators for continuous activator regeneration (ICAR) RCMP, as inspired by the denomination of ICAR ATRP. The synthesis of poly (methyl methacrylate) (PMMA) ( M w / M n < 1.3) with good controllability was achieved via this technique when the concentration of the deactivator complex was as low as dozens of ppm. The studied three kinds of iodine complexes showed high control on the polymerization of MMA. The effects of initiator and deactivator complex concentration on the polymerization process were researched in detail. Furthermore, the accessibility of PMMA prepared by ICAR RCMP to chain extension and block copolymerization confirmed that this novel polymerization approach afforded polymers with high chain-end fidelity. The substantial decrease in the concentration of deactivator complex or activator plays a critical role for the production and application of well-defined polymer prepared by this method.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2024
·Vol. 53
·期 6
·3089-3099
·
IF 2.2
Zhao Wenxia,Hui Kaihong,Zhao Wei,Chen Huaijun,Cui Yubo,Li Xinwei,Liu Xin,Song Yifan,Hui Kaining,Yan Yani,Qiao Liang,Wang Zenglin
The effects of additives on the deposition rate, surface morphology, Ni and P elemental content of the electroless plating layer, and roughness of the electroless plating Ni-P layer were investigated. In an electroless plating Ni-P system, ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) and sodium hypophosphite monohydrate were used as the complexing agent and reductant, respectively. The linear sweep voltammetry (LSV) polarization curve results showed that the compound addition of 1.0 mg L −1 L-tyrosine, 2.0 g L −1 saccharin, and 6.0 mg L −1 sodium dodecyl sulfate (SDS) could inhibit sodium hypophosphite oxidation and nickel ion reduction, which eventually reduced the Ni-P deposition rate. The Tafel polarization curves indicated that the compound additives obviously improved the corrosion resistance of the Ni-P electroless plating layer. Field emission scanning electron microscopy (SEM) images showed that the composite additives generated fine and uniform Ni-P electroless plating particles and enhanced the density, eliminated the surface cracks, and reduced the pinholes on the electroless plating layer surface. Atomic force microscopy (AFM) tests showed that the addition of complex additives improved the smoothness of the plated layer, the R a value was reduced from 135.0 nm to 53.2 nm, and the R q value was reduced from 164.0 nm to 93.0 nm. The final composition and implementation conditions of the EDTA-2Na-based Ni-P electroless plating system were determined. The deposition rate was 10.44 μm h −1 , the P content of the electroless plating layer was 2.2%, and the electroless plating player was silver-white and bright. Graphical Abstract
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高影响因子
危险品化学品经营许可证（带存储）