JOURNAL OF POROUS MATERIALS
·
2019
·Vol. 27
·期 1
·295-301
·
IF 1.947
Zhang Jiayue,Kong Yong,Jiang Xing,Zhong Ya,Chen Ying,Shen Xiaodong
Hydrophobic silica aerogel (HSA) was synthesized by a facile sol–gel method and ambient pressure drying with methyltrimethoxysilane as precursor. The effect of precursor concentration on the sol–gel behavior, structure, and thermal conductivity of HSA was investigated. HSA with apparent density of 0.088 g/cm 3 showed a thermal conductivity of 0.018 W/(m·K), a specific surface area of 502 m 2 /g and a pore volume of 1.66 cm 3 /g. The hydrophobic groups in HSA had a good thermal stability up to 450 °C. Polypropylene felt was used to synthesize hydrophobic silica aerogel composite (HSAC). The effect of sol loading on the structure and thermal conductivity of HSAC was investigated. HSAC with equivalent sol loading exhibited a low shrinkage of 2.5% and a low thermal conductivity of 0.020 W/(m·K). Finally, the preparation method of the HSA is facile and environmentally friendly, and the resulting composite is a promising candidate for thermal insulation under humid environments.
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MICROCHIMICA ACTA
·
2019
·Vol. 187
·期 1
·1-9
·
IF 5.479
Zhang Wanqing,Fan Shumin,Li Xinli,Liu Shanqin,Duan Dawei,Leng Leipeng,Cui Chengxing,Zhang Yuping,Qu Lingbo
A glassy carbon electrode (GCE) was modified with a composite prepared from phytic acid, polypyrrole and a ZIF type metal-organic framework (PA/PPy)/ZIF-8@ZIF-67). The nanocomposite was prepared by in-situ chemical polymerization in the presence of ferric chloride and subsequently functionalized with PA to form PA/PPy/ZIF-8@ZIF-67. The materials were characterized by XRD, FT-IR, BET, XPS, SEM and TEM. The modified GCE was applied to individual and simultaneous detection of Pb(II) and Cu(II), with peak voltages of −0.6 and − 0.1 V, respectively (vs. SCE). The amount of PPy, the ZIF-8@ZIF-67 concentration, polymerization potential, polymerization time and pH value were optimized. Under optimized conditions, the calibration plots have two linear ranges. These are from 0.02 to 200 μM and from 200 to 600 μM for Pb(II), and from 0.2 to 200 μM and 200 to 600 μM for Cu(II). The detection limits are 2.9 nM and 14.8 nM, respectively. Simultaneous detection of Pb(II) and Cu(II) is also demonstrated. The good performance of the electrode is attributed to the large surface area of ZIF-8@ZIF-67, the good electrical conductivity of PPy, and the metal complexation power of PA. The modified GCE was successfully applied to the determination of Pb(II) and Cu(II) in real samples and gave satisfactory recoveries.
Schematic presentation of the construction process of PA/PPy/ZIF-8@ZIF-67/GCE sensor, and the mechanism of Pb(II) and Cu(II) at the prepared sensor.
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 187
·期 1
·1-10
·
IF 5.479
Li Yue,Wang Yan,Wang Mingchao,Zhang Jinyue,Wang Qingwei,Li Hongji
In a new method for the determination of trace levels of chlorophenols in river waters, detection via surface-enhanced Raman scattering (SERS) is combined with recognition by a molecularly imprinted polymer (MIP). Nanoparticles of type Cu 2 O@Ag were synthesized by attaching silver particles to the surface of Cu 2 O nanoparticles. The Cu 2 O@Ag were then coated with a layer of a MIP that was obtained by atom transfer radical polymerization using from methacrylic acid as monomers and 2,6-dichlorophenol as the template. The morphology of Cu 2 O is found to be flower-like. The Cu 2 O@Ag-MIPs displays a strong SERS effect. Following removal of the template by rinsing with the mixture solution of methanol/acetic acid (9/1, v /v), the material was used to selectively bind 2,6-dichlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenol. The SERS peak intensity at 1580 cm −1 increases linearly with the concentration of the various chlorophenols in the range from 10 nM to 1 mM, and the detection limit is 5.8 nM. The imprinting factor is 4.62. The method was applied to the analysis of (spiked) river water, with recoveries ranging from 91.8 to 115.4% and relative standard deviations of <4.5%.
Graphical abstract
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高影响因子
IONICS
·
2019
·Vol. 26
·期 3
·1347-1356
·
IF 2.289
Qu Yuning,Wen Shuya,Chen Jianhong,Shen Honghui,Yu Wenjie,Wei Dan,Yu Jianguo,Kwon Young-Uk,Zhao Yongnan
In this work, we synthesized a Pd nanonetwork (PdNN) catalyst by employing Nafion as structure-directing agent. The nanonetwork-like structure is interconnected by Pd particles. Moreover, the morphologies and the sizes of PdNN samples can be tunable by adjusting concentrations of Pd precursor. The as-prepared PdNN catalysts have superior hydrogen evolution reaction (HER) performance to that of commercial Pd/C. Among them, PdNN-4.5 catalysts exhibit the most excellent hydrogen evolution performance, which contains an overpotential of 59 mV at 10 mA cm -2 and a Tafel slope of only 54 mV dec -1 . Besides, a super stability is also displayed for PdNN-4.5 catalysts. The significant improvement in the HER performance of the PdNN-4.5 catalyst may be attributed to the nanonetwork-like structure, the sizes, and the interaction between the Pd catalysts and Nafion. Thus, this work can provide a simple method for synthesizing the highly efficient Pd-based catalyst for HER.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 20
·18617-18625
·
IF 2.195
Meng Zuchao,Li Mao,Liu Xiang,Lei Zigang
A new hydrazine electrochemical sensor was fabricated based on in situ synthesis of Cu 3 (BTC) 2 /GO nanocomposite. Cu 3 (BTC) 2 /GO composite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometry (FT-IR). Meanwhile, the electrochemical behaviors of hydrazine on the Cu 3 (BTC) 2 /GO/GCE were studied by cyclic voltammetry and linear sweep voltammetry. Under the optimized conditions, Cu 3 (BTC) 2 /GO/GCE had enhanced electrocatalytic activity toward hydrazine due to synergic catalytic effect between Cu 3 (BTC) 2 and GO. The electrochemical sensor exhibited a wider linear range (1.0 µM to 5000 µM) and a lower detection limit (0.5 μM) as well as good reproducibility and stability. The proposed sensor has also been used for the determination of hydrazine in tap water with satisfactory results.
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CELLULOSE
·
2022
·Vol. 30
·期 2
·801-813
·
IF 6.123
Wei Chunjie,Liu Gang,Xie Yujiao,Sun Zhongyuan,Liu Chang,Song Feng,Cui Hongyou
Molten salt hydrate (MSH) is a good solvent for cellulose dissolution and an effective catalyst for cellulose conversion. In this work, a series of MSH was evaluated in terms of cellulose dissolvability, regeneration performance, and catalytic activity in cellulose conversion into 5-hydroxymethylfurfural (HMF). ZnBr 2 ·3H 2 O–LiCl·3H 2 O showed good performance on cellulose dissolution and conversion. The effects of ZnBr 2 ·3H 2 O concentration, reaction temperature, and time on cellulose conversion into HMF in ZnBr 2 ·3H 2 O–LiCl·3H 2 O were optimized, and 48.7% HMF yield was reached at 60 wt.% ZnBr 2 ·3H 2 O. The species of ZnBr 2 ·3H 2 O–LiCl·3H 2 O were analyzed, and the function of species concentration was correlated with the product yield from the conversion of fructose. It was found that Br − and H + were the active species for fructose dehydration into HMF. ZnBr 3 − and H + catalyzed the conversion of fructose into furfural, which competed with the production of HMF. The reaction mechanism was proposed to understand the cooperate of species in MSH for cellulose conversion.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 7
·18364-18379
·
IF 5.19
Zhang Xiao,Li Zhiyue,Zhang Taoyi,Chen Jing,Ji Wenxi,Wei Yun
A low-cost and environmental-friendly sodium alginate-melamine@zeolitic imidazolate framework-67 (SA-ME@ZIF-67) adsorbent was fabricated by chemical grafting and in situ growth for the removal of lead ions in wastewater. Firstly, melamine (ME) was grafted onto sodium alginate (SA) by amide reaction, and then SA-ME was dropped into a solution of calcium chloride to form hydrogel bead, and ZIF-67 was grown on the SA-ME hydrogel bead by the in situ growth method. The SA-ME@ZIF-67 adsorbent was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The SA-ME@ZIF-67 adsorbent was used to effectively adsorb Pb(II) from aqueous solutions. The initial concentrations of lead ions, adsorbent dose, initial pH of lead ion solution, temperature, and adsorption time for the material were optimized. The adsorption isotherms and kinetics fitted to Langmuir isotherm model ( R 2 = 0.9281, 0.9420, and 0.9623 at the temperatures of 288.15 K, 298.15 K, and 308.15 K, respectively) and pseudo-second-order kinetic model ( R 2 = 0.9901) respectively. According to the Langmuir model at 308.15 K, the maximum adsorption capacity of the adsorbent for Pb(II) was 634.99 mg/g. The recycling application of the adsorbent was possible as it was easily collected and reused after five adsorption-regeneration cycles. In addition, the Pb(II) in real wastewater samples has been efficiently removed using the fabricated hydrogel. The results showed that the SA-ME@ZIF-67 adsorbent had high adsorption capacity, removal efficiency, and easy recyclability for Pb(II). Graphical abstract
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高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-14
·
IF 17.694
Sun Mengmeng,Hao Bo,Yang Shihao,Wang Xin,Majidi Carmel,Zhang Li
Miniature magnetic soft machines could significantly impact minimally invasive robotics and biomedical applications. However, most soft machines are limited to solid magnetic materials, whereas further progress also relies on fluidic constructs obtained by reconfiguring liquid magnetic materials, such as ferrofluid. Here we show how harnessing the wettability of ferrofluids allows for controlled reconfigurability and the ability to create versatile soft machines. The ferrofluid droplet exhibits multimodal motions, and a single droplet can be controlled to split into multiple sub-droplets and then re-fuse back on demand. The soft droplet machine can negotiate changing terrains in unstructured environments. In addition, the ferrofluid droplets can be configured as a liquid capsule, enabling cargo delivery; a wireless omnidirectional liquid cilia matrix capable of pumping biofluids; and a wireless liquid skin, allowing multiple types of miniature soft machine construction. This work improves small magnetic soft machines’ achievable complexity and boosts their future biomedical applications capabilities.
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高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2022
·Vol. 147
·期 23
·13351-13361
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IF 4.755
Shi Yanqin,Chen Lukai,Ma Biao,Lu Songyan,Chen Si,He Huiwen,Ma Meng,Wang Xu
An excellent migration resistant thermal stabilizer, an oligomer of bis-uracil derivative (P-UESU), was synthesized by the polymerization of UESU. The UESU was obtained by the reaction of 10-undecenyl aldehyde and 6-amino-1,3-dimethyluracil (DAU). The results of FTIR, DSC, and MS indicated that UESU and P-UESU were synthesized successfully, and P-UESU was an oligomer with more than four polymerization degrees. P-UESU could be used as the thermal stabilizer for PVC due to its high thermal stability. The super low migration ratio of P-UESU in PVC was proved by the migration resistant test, which is lower than 0.2%, better than OSU, USU, and commercial Ca/Zn thermal stabilizers. The reasons were ascribed to its big molecular volume and the physical entanglement with PVC molecular chains, which was confirmed by Flory–Huggins theory. Moreover, the static and dynamic thermal stability time of PVC with P-UESU/ESBO/TPP reached more than 160 min and 41 min, respectively. It was interesting that the excellent migration resistance of P-UESU was not affected by the addition of the auxiliary thermal stabilizers. The tensile strength and elastic modulus of PVC were also high, which were 26.93 MPa and 28.85 MPa. In conclusion, P-UESU had a good application prospect in practical application due to its excellent migration resistance and good thermal stability effect on PVC.
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Food Analytical Methods
·
2022
·Vol. 16
·期 2
·318-329
·
IF 3.498
Yun Ning,Lu Chaoqun,Sun Tian,Xu Baocai,Song Yushen,Zong Zibing,Chen Kangwen,Huang Ganhui,Chen Xingguang,Gu Qianhui
Red pepper oil is a kind of condiment used in food factories, and its spicy degree can be reflected by the content of capsaicin. However, the classification method of red pepper oil is too subjective to be applied in food factories. In our work, a sensitivity electrochemical sensor for detecting capsaicin was constructed based on the glassy carbon electrode (GCE) modified with β-cyclodextrin (β-CD) assisted reduced graphene oxide (rGO). The results showed that the introduction of β-CD made rGO more dispersed, increasing the electrochemical active surface area of β-CD/rGO, thus improving the charge transfer rate. Furthermore, polycyclodextrin with selective recognition ability was dispersed on the surface of rGO, providing the possibility of capsaicin enrichment on the surface of the sensor. Based on these reasons, the sensor had a lower detection limit (0.05 μg/mL), and acceptable stability and anti-interference. Most importantly, β-CD/rGO/GCE displayed a satisfactory recovery rate (94.83 ~ 115.75%) in the detection of red pepper oil, and there was no statistical significance difference between this method and the LC–MS method.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 3
·2413-2418
·
IF 2.195
Hu Bo,Yang Fan,Peng Ye,Hang Chunjin,Chen Hongtao,Lee Changwoo,Yang Shihua,Li Mingyu
Ag nanoparticle (NP) paste is considered to be a next-generation thermal interface material. However, its sintered microstructure is at risk of volume shrinkage and mechanical property degradation under harsh environments. In this work, silicon carbide (SiC) NPs were mixed with Ag NP paste to improve the stability and reliability of sintered Ag joints. Robust joints were prepared by a rapid thermal compression method at 275 °C for 20 s. Although the addition of SiC NPs degraded the initial shear strengths of these joints, the SiC-containing joints exhibited excellent mechanical properties and microstructural stability during thermal shock tests from − 50 to 150 °C for up to 1000 cycles. When the added amount of SiC NPs was 2%, the joints achieved the highest shear strength of 87.1 MPa (after 1000 cycles). In addition, the shear strengths of the joints were investigated at 250 °C. The addition of SiC NPs is believed to enhance the reliability of joints at high temperature.
研究领域:
材料科学
·
纳米技术
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EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2019
·Vol. 245
·期 4
·825-835
·
IF 2.056
Zhong Jian-Jun,Liao Ningbo,Li Charlie,Wang Wenjun,Wang Danli,Pu Yunfeng,Ye Xingqian,Liu Donghong
Urocanic acid, deaminated histidine and the first intermediate in the histidine utilization (Hut) pathway in bacteria, has recently been suggested to have adverse health effects by inducing scombrotoxicosis and immunosuppression after trans – cis isomerization. This work aimed to shed some light on the microbiology of its formation in scombroid fish, given that such information is very scarce. The isolation of urocanic acid producers from chub mackerel was basically based on enrichment of bacteria possessing the Hut pathway with histidine as the sole source of carbon, energy, and nitrogen. Morphological and molecular identification revealed that the isolates ( n = 12), taken from the skin, gills, and intestine, were comprised entirely of Acinetobacter from at least five species. This implies that the Hut pathway in the microbes can be particularly active and as such conferred a growth advantage. Dynamic monitoring of bacterial growth and urocanic acid production in fish juice broth indicated that urocanic acid is a primary metabolite and its production is a closely growth-associated process. This in turn implies that its production can be controlled directly by suppressing the bacterial growth. Several potential methods are proposed through a study of the growth characteristics and preservative susceptibility of representative isolates. In conclusion, this work suggests that Acinetobacter can constitute a potentially important group of urocanic acid producers in chub mackerel.
研究领域:
微生物学
·
食品安全
·
健康科学
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危险品化学品经营许可证（带存储）