APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2021
·Vol. 127
·期 10
·1-9
·
IF 2.584
Zhang Yu,Cao Ping,Lin Wei,Liu Qiang,Chen Ziyuan,Cao Jun,Yang Guannan,Cui Chengqiang
In this paper, a mixed sintering accelerator of colophony and cetyltrimethyl ammonium bromide (CTAB) was developed to improve the sintering properties of Cu nanoparticles (NPs) paste. With the synergy effect of the mixed sintering accelerator, Cu NPs paste could be well sintered at 260 °C for 30 min under a pressure of 2 MPa, and the shear strength was greatly improved from 15 to 33 MPa. The fracture morphology of the Cu NPs joint transformed from brittle interface failure features to ductile dimple features, and the porosity in the sintered layer was significantly reduced. XRD analysis further confirmed that the synergy of colophony and CTAB could effectively remove the oxides in the Cu NPs paste during sintering, and thereby improve the sintering properties. This work can provide an applicable approach to improve the sintering properties of metal NPs and help to understand the synergy effect of sintering accelerators on the bonding behaviors of metal nanoparticles at low temperatures. Graphic abstract
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JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 8
·1-13
·
IF 2.184
Qin Jianbin,Zhang Guangcheng,Shi Xuetao,Tao Min
The dispersions was prepared by dispersing hydrophilic silica nanoparticles with an average diameter of 50 nm in 1-butyl-methylimidazolium tetrafluoroborate ([C 4 mim][BF 4 ]), and investigated under the steady shear and oscillatory shear, respectively. Experimental results indicate that all of the dispersions present shear thinning, notable shear thickening, and shear thinning successively with increasing shear rate; the shear thickening behavior is derived from silica nanoparticle clusters and strongly controlled by silica nanoparticle content and temperature. The shear thickening fluid (STF) exhibits reversible property and transient response ability, and the time of transient response is no more than 100 ms. The conductivity of the STF is increased with increasing silica nanoparticle content, and the conductivity of 27 wt% dispersions is even two times as big as that of pure [C 4 mim][BF 4 ]. The dispersions with high solid content dilate and present a phase transition changing from a liquid-like to a solid-like soft material in the shear thickening region. A theoretical model is developed to imitate the mechanism of shear thickening in the dispersions.
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Journal of Food Measurement and Characterization
·
2022
·Vol. 16
·期 5
·3501-3511
·
IF 3.006
Chen Hongshuo,Liu Haibin,Cui Chuanjin,Zhang Xuechao,Yang Wei,Zuo Yueming
To effectively cut off the transmission of Brucella to humans through milk, a novel biosensor for detection of Brucella was constructed using cysteamine functionalized nanogold (Cys-Au) and 4-Mercaptobenzoic acid (4-MBA) modified gold electrode as the platform. The morphology of the prepared nanomaterials was characterized by laser particle sizer, XPS and SEM, and the results showed the 4-MBA film was modified on the gold electrode surface, and the diameter of successfully prepared nanogold and Cys-Au are about 55 and 65 nm, respectively. The electrochemical performance of the biosensor was tested in Brucella antigen solution by square wave voltammetry (SWV). The results showed the reproducibility and stability of the biosensor were good, the spiked recovery in milk was in the range of 95.12–105.27%, and the minimum detection limit (S/N = 3) was 5.12 × 10 2 cfu/mL with a linear range from 1.6 × 10 2 to 1.6 × 10 8 cfu/mL. In addition, the minimum detection limit was reduced from 5.12 × 10 2 cfu/mL to 7.0 × 10 1 cfu/mL after processing the SWV data by second-order derivative transformation, which showed Second-order derivative transformation is very helpful to further optimize the performance of the sensor. Compared with the previously reported test methods, the prepared biosensors have a wider linear range and lower limit of detection (LOD). Therefore, the constructed biosensor can be used as a promising tool for the trace detection of Brucella in milk samples.
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2009
·Vol. 288
·期 2
·173-179
·
IF 1.736
Chen Jiucun,Wang Haodong,Luo Wenqian,Xiang Jiming,Zhang Lihui,Sun Baoben
In this work, by a combination of controlled ring-opening polymerization (CROP) and click chemistry, we report a facile and useful method to synthesize linear poly(ε-caprolactone)@attapulgite nanocomposites with well-defined structures. For this, first, the chlorine-terminated attapulgite was prepared by the self-assembly of 3-chloropropyltrimethoxysilane from the surfaces of attapulgite. And then, the terminal chlorines of modified attapulgite were substituted with azido groups. As the second step, linear propargyl-terminated poly(ε-caprolactone) (PCLs) with different molecular weights were synthesized by the CROP of ε -CL monomer in toluene with stannous octoate as a catalyst and propargyl alcohol as an initiator. The structural characteristics of the obtained linear PCLs have been determined by 1 H NMR and gel permeation chromatography analysis. Finally, the azido-terminated attapulgite was reacted with propargyl-terminated PCLs via the click reaction.
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高影响因子
Frontiers of Environmental Science & Engineering
·
2021
·Vol. 16
·期 8
·1-10
·
IF 4.357
Shen Zhichao,Zhan Lu,Xu Zhenming
Current study proposes a green regeneration method of activated carbon (AC) laden with Perfluorochemicals (PFCs) from the perspective of environmental safety and resource regeneration. The defluorination efficiencies of AC adsorbed perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonate (PFBS) using three molten sodium salts and one molten alkali were compared. Results showed that defluorination efficiencies of molten NaOH for the three PFCs were higher than the other three molten sodium salts at lower temperature. At 700°C, the defluorination efficiencies of PFOS and PFBS using molten NaOH reached to 84.2% and 79.2%, respectively, while the defluorination efficiency of PFOA was 35.3%. In addition, the temperature of molten salt, the holding time and the ratio of salt to carbon were directly proportional to the defluorination efficiency. The low defluorination efficiency of PFOA was due to the low thermal stability of PFOA, which made it difficult to be captured by molten salt. The weight loss range of PFOA was 75°C–125°C, which was much lower than PFOS and PFBS (400°C–500°C). From the perspective of gas production, fluorine-containing gases produced from molten NaOH-treated AC were significantly reduced, which means that environmental risks were significantly reduced. After molten NaOH treatment, the regenerated AC had higher adsorption capacity than that of pre-treated AC.
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2018
·Vol. 35
·期 8
·1642-1649
·
IF 2.199
Wang Yushun,Du Tao,Fang Xin,Meng Da,Li Gang,Liu Liying
CO 2 capture from humid flue gas is always costly due to the irreplaceable pretreatment of dehydration in current processes, which creates an urgent demand for moisture-insensitive adsorbents with considerable CO 2 uptakes as well as remarkable H 2 O tolerances. In the present work, the microporous titanium silicate molecular sieve ETS-10 was synthesized with coal fly ash as the only silica source. The as-synthesized ETS-10 was characterized by X-ray diffraction, scanning electronic microscopy and infrared spectroscopy to verify its crystal morphology, in which neither impurity nor aggregation was observed. The following CO 2 adsorption experiments on the thermal gravimetric analyzer demonstrated its similar CO 2 adsorption capacity yet dramatical adsorption kinetics among some other microporous materials, e.g., potassium chabazite. These specific properties consequently guaranteed its favorable CO 2 adsorption capacity even at high temperatures (1.35 mmol/g at 393 K) and shortened the breakthrough time of single CO 2 flow to less than 20 s. In CO 2 /H 2 O binary breakthrough experiments, the as-obtained ETS-10 still maintained excellent CO 2 uptake of 0.81 mmol/g at 323 K, regardless of the presence of water vapor, making it a promising substitute for direct CO 2 separation from humid flue gases at practical conditions of post-combustion adsorption.
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2021
·Vol. 128
·期 1
·1-14
·
IF 2.584
Zhang Dandan,He Yipeng,Wang Rumin,Taub Alan I.
Carbon nanotubes (CNTs) orient in a polymer matrix under electric field due to their highly anisotropic electric polarizability. Under direct current (DC) electric field, CNT also migrates toward electrodes resulting in a non-uniform CNT concentration which can affect the properties gained from CNT alignment. In this study, DC electric field was applied across a CNT/epoxy mixture and the kinetics of CNT migration were studied in real time as a function of electric field strength, CNT concentration and length distribution. The rate constant k of CNT migration was found to be linearly proportional to the electric field strength, while varying the CNT concentration and length distribution exhibited a minimal effect on the migration velocity. Combined with our previous study of the temperature dependence of CNT migration, the relationship between the rate constant k of CNT migration and electric field strength, CNT concentration and length distribution was established. The resulting relationship can be used to manipulate the spatial distribution of CNT to selectively enhance the mechanical, thermal and electrical properties of CNT/polymer composites.
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Nature Catalysis
·
2019
·Vol. 2
·期 12
·1107-1114
·
IF 0
Li Zhe,Fu Jian-Yu,Feng Yi,Dong Cun-Ku,Liu Hui,Du Xi-Wen
Finding highly active and low-cost catalysts is a crucial endeavour to harvest clean hydrogen via electrochemical water splitting. Currently, the best catalyst for the hydrogen evolution reaction is based on metallic platinum whose high price severely restricts large-scale application. Here we report a silver catalyst with superior activity and durability in an acid medium that outperforms commercial platinum on carbon, especially under high applied voltages. We adopt a physical technique—laser ablation in liquid—to generate a high density of stacking faults in silver nanoparticles. We find that the stacking faults can cause a low coordination number and high tensile strain, which jointly improve the adsorption energy and transform the non-active silver into a highly active catalyst. In light of the high activity, conductivity, durability and low price, the silver catalyst can serve as a promising alternative to commercial platinum on carbon for industrial application.
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Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Wu Jian,Chen Zhen,Wang Jun,Wang Yiqun,Jiang Jian,Xiao Weiqiang,Xia Qian,Zhang Jiabao,Zhou Guojun,Zhang Junsong,Liang Miao
Cigar tobacco residues are a special air-cured tobacco material with increasing production in domestic. In this present study, the effect of glycerol addition on the pyrolysis characteristic, kinetic behavior, and release of pyrolytic products was investigated by using thermogravimetry coupled with online FTIR and self-built infrared tubular furnace. The thermal weight loss process of cigar tobacco could be divided into four stages, and the glycerol exhibited significant impact on the pyrolysis process. The stage II corresponding the decomposition of volatile components and hemicellulose shifted to the lower temperature accompanied with an increase of DTG max and weight loss at this stage. The T i , T f , and residues were decreased, while the CPI was increased as for the CT-G sample, indicating an increased reactivity and comprehensive pyrolysis performance. Gauss peak fitting was used to separate the pyrolysis process of different pseudocomponents in the tobacco biomass. Pyrolysis kinetic analysis based on Coats-Redfern method showed that the activation energy for the decomposition of each pseudocomponents decreased after the addition of glycerol. The online FTIR and MS analysis also reflected the interaction between glycerol and biomass through the release of pyrolytic gaseous products. GC–MS was further used to analyze the compositions of pyrolytic products in the trapped particulate matter under different heating rates. High heating rate was beneficial for the sufficient release of pyrolysis products and aroma compounds. The glycerol addition inhibited the generation of alkaloids, phenols, esters, ketones, acids, and heterocyclic compounds, indicating some effect may exist between cigar tobacco and glycerol.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 1
·323-336
·
IF 2.478
Fan Jilei,Li Gang,Rajavel Krishnamoorthy,Zhu Pengli,Sun Rong,Wong Ching-Ping
Electrically conductive epoxy adhesive, which combines with Ag sintering materials rather than traditional Pb-based solder materials, attracts wide research interest in modern die attach technology for power electronic packaging owing to its advantages of low processing temperature and high working temperature. In this work, Cu foil and AgNO 3 were used as raw materials to synthesize dendritic silver nanostructure with a central trunk of 5–10 μm along with many primary branches of 200 nm. Subsequently, the sintering behavior of the obtained dendritic Ag nanostructures, as low-temperature interconnect material, was systematically investigated under different sintering conditions. Remarkably, the shear strength of the interconnect joints formed from dendritic Ag nanostructures could reach around 21 MPa after sintering for 30 min at 250 °C under a pressure of 10 MPa, whereas the shear strengths of the interconnect joints, which formed from Ag microspheres and microflakes under similar conditions, were only 9 MPa and 11 MPa. We think that the dramatic increment in the shear strength may result from the higher contact area of nanoscale primary branches of the synthesized dendritic structures than Ag microstructures and the low-temperature sintering of their nanoscale primary branches. In addition, the interconnect joint formed from dendritic Ag nanostructures also exhibited high reliability, and it still maintained a high shear strength of 27 ± 2 MPa even after 1000 cycles thermal quenching between − 55 and 125 °C. The thermal resistance and electrical conductivity of these interconnect joints were about 78.89 Wm −1 K −1 and 9.85 × 10 –6 Ω cm, respectively, which makes its further interconnect applications feasible. This means that the synthesized special dendritic Ag nanostructure has an excellent potential as a high-performance die attach material for high- and low-temperature power device.
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CHROMATOGRAPHIA
·
2014
·Vol. 77
·期 23
·1705-1712
·
IF 1.37
Zhaoling Jiang,Lifang Zhang,Chong Zhang,Xiao Zhang,Feiqun Xue
Ultra high performance liquid chromatography with UV detection was developed and validated for the simultaneous determination of residues of toltrazuril and its two metabolites, namely, toltrazuril sulphone and toltrazuril sulphoxide, in edible tissues (chicken and porcine muscle, liver and kidney). Acetonitrile was used to extract analytes from tissues, which were then cleaned using primary secondary amine and Oasis™ MAX solid phase extraction cartridges. Chromatographic separation was performed on a C 18 column with gradient elution. The analytes were determined using a UV detector. The regression coefficients of matrix-matched calibration curves showed linearity of >0.99. Calibration ranged from 25 to 1,000 μg kg −1 for toltrazuril and toltrazuril sulphone, and 37.5–1,500 μg kg −1 for toltrazuril sulphoxide. The accuracy was between 80 and 110 %, and the inter and intraday RSDs were lower than 15.2 and 18.3 %, respectively. The limits of detection for toltrazuril, toltrazuril sulphone and toltrazuril sulphoxide were between 10 and 37.5 μg kg −1 in all the tissues. The developed method was successfully applied to detect toltrazuril, toltrazuril sulphone and toltrazuril sulphoxide in tissues of medicated chicken.
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高影响因子
JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 2
·1-8
·
IF 1.92
He Zhicai,Zhong Mingqiang,Yang Jintao
Aiming to prepare polystyrene microcellular foam with improved foam morphology and high thermal stability, ionic liquids which have been well demonstrated to possess high carbon dioxide (CO 2 ) absorption capacity were introduced into polystyrene by copolymerization of styrene and polymerizable ionic liquids, i.e., vinylbenzyl trimethyl ammonium fluoroborate ([VBTMA][BF 4 ]) and vinylbenzyl trimethyl ammonium hexafluorophosphate ([VBTMA][PF 6 ]), Abbr. ILs). These copolymers showed higher glass transition temperature (T g ) and high supercritical carbon dioxide (scCO 2 ) solubility, based on which foams with smaller cell size, higher cell density, and higher thermal stability were prepared by the microcellular foaming using scCO 2 as blowing agent. The morphology of the resultant foams highly depended on the foaming temperature, ionic liquid type and content. Compared to [VBTMA][BF 4 ]-St foam, [VBTMA][PF 6 ]-St have higher CO 2 absorption and glass-transition temperature, making it exhibit superior cell morphology. This work demonstrates that the introduction of ionic liquids can benefit the morphology control and thermal stability of polymeric foams and hopefully provides a promising method for the design and preparation of polymeric foams with high performance.
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危险品化学品经营许可证（带存储）