POLYMER BULLETIN
·
2020
·Vol. 78
·期 1
·415-432
·
IF 2.014
Chen Liduo,Ma Lili,Jiang Yan,Liu Jinyi,Li Cuiqin,Zhang Na,Wang Jun
The (6 E ,7 E )- N 1 , N 4 -bis((pyridin-2-yl)methylene)benzene-1,4-diamine ligand L-0 was prepared in order to synthesize the corresponding pyridine imine metal (iron, cobalt and nickel) complexes Fe-1 , Co-2 and Ni-3 . The structures of the ligand and its corresponding metal complexes were characterized by element analysis, NMR, IR, UV–Vis and ESI–MS. Upon activation with cocatalyst, the metal complexes Fe-1 , Co-2 and Ni-3 exhibited moderate catalytic activity, and the oligomer products were mainly 1-butene. The influence of reaction parameters, such as solvent type, Al/M (M = Fe, Co, Ni) molar ratio, reaction temperature, reaction pressure and cocatalyst type, on catalytic properties was investigated in detail. Ethylene oligomerization data suggested that metal center had an important impact on catalytic performance. In most cases, attributed to electron effects, Fe-1 had better catalytic activity than Co-2 and Ni-3 at the same reaction conditions, and Ni-3 had better catalytic selectivity toward high-carbon olefins (≥ 1-decene). The density functional theory calculations were utilized to optimize the geometry structure for exploring the relationship between structure and catalytic properties, which provides a possibility of predicting the catalytic selectivity in ethylene oligomerization. Moreover, the catalytic mechanism was further studied for better understanding of ethylene oligomerization process catalyzed by Fe-1 , Co-2 and Ni-3 . Graphic abstract The para-phenylene-linked pyridine imine metal (iron, cobalt and nickel) complexes have the ability of catalyzing ethylene oligomerization. Attributed to electron effects, their catalytic properties including activity and selectivity are different.
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高影响因子
JOM
·
2018
·Vol. 70
·期 4
·575-580
·
IF 2.145
Zhou Zhongren,Zhang Yingjie,Hua Yixin,Xu Cunying,Dong Peng,Zhang Qibo,Wang Ding
The effect of CaO content on the preparation of ferrotitanium alloys from ilmenite with the method of the electrolysis-assisted calciothermic reduction has been investigated by use of ilmenite powders as raw materials that positions them next to the cathodic molybdenum plate,
equimolar CaCl 2 -NaCl molten salt with 2–7 mol.% CaO as electrolyte and graphite as anode at 700°C with cell voltage of 2.8 V under argon atmosphere.
It is demonstrated that increasing the reactant CaO content is beneficial to the calciothermic reduction of ilmenite and the intermediate CaTiO 3 . Experimental results also show that after 14 h of calciothermic reduction process, the products are ferrotitanium alloys and the specific energy consumption is only about 10.21 kWh kg −1 when adding 5 mol.% CaO into equimolar CaCl 2 -NaCl molten salt and approximately 14.40 kWh kg −1 when CaO content is increased to 7 mol.%.
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高影响因子
Waste and Biomass Valorization
·
2024
·Vol. 15
·期 7
·4353-4372
·
IF 2.6
Shankaranarayana Sahana Hosanagara,Gajanana Vijayalaxmi Karki,Chavan Mohan,Chavannavar Suvarna V.,Doddanagappa Shobha
Purpose To analyse phytochemical composition, antioxidant potential, antimicrobial activity and α-amylase, α-glucosidase and xanthine oxidase inhibitory potential of corn silk extracts derived from the Syngenta 5414 corn variety. Methods Corn silk sample was lyophilized and extracted using 80% ethanol, methanol, water or acetone. Phytochemicals were qualitatively screened and bioactive compounds were identified through GCMS. Antimicrobial activities were evaluated using the agar well method for bacteria and fungal biomass method for fungi. The extracts were subjected to evaluation for their antidiabetic activity through α-amylase and α-glucosidase inhibitory assays, while their anti-gout potential was assessed through xanthine oxidase inhibitory assay, encompassing all four solvent extracts in the study. Results Phytochemical screening revealed the presence of phenols, flavonoids, tannins, alkaloids, sterols, protein xanthoproteic, and cardiac glycosides in the extracts. The Folin-Ciocalteu and AlCl 3 assays demonstrated higher yields of phenolics and flavonoids in 80% ethanolic extract. Furthermore, the extracts remarkably scavenged reactive oxygen species like DPPH, ABTS and elicited considerable ferric ion reducing antioxidant power. GC–MS analysis identified 21 compounds in the 80% ethanolic extract, with 1,2,3-Propanetriol-1-acetate, n-Hexadecanoic acid, and 4H-Pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl- as major components. Antimicrobial assays demonstrated the ethanolic (80%) and methanolic extract's remarkable ability to inhibit the growth of Gram-positive bacteria and exhibit anti-fungal properties. The ethanolic (80%) extract exhibited an IC 50 value of 0.70 ± 0.02 and 0.71 ± 0.01 mg against α-amylase and α-glucosidase, respectively, and 33.76 ± 0.43 mg against xanthine oxidase. Conclusion Corn silk exhibits potential as a valuable reservoir of natural bioactive compounds endowed with a wide array of health-promoting properties. Graphical
研究领域:
天然产物化学
·
药用植物学
·
生物化学
·
药物代谢
·
微生物学
·
内分泌药理学
·
代谢性疾病
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高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2016
·Vol. 122
·期 5
·515
·
IF 1.444
Huang Liang,Zhu Pengli,Li Gang,Sun Rong
The partial reduced graphene oxide (P-rGO) sheets-wrapped nickel foams (NF@P-rGO) were prepared by hydrothermal method, and then their epoxy composites were fabricated via a simple drop-wetting process. The P-rGO sheets on the metal networks could effectively improve the compatibility between nickel foam and epoxy resin, thus greatly accelerate the wetting of epoxy resin on the foams and avoid cracks in the network–polymer interface. Owing to the existence of high-efficiency conductive metal networks, the NF@P-rGO/epoxy composite has a high thermal conductivity of 0.584 W m −1 K −1 , which is 2.6 times higher than that of neat epoxy resin. Additionally, owing to the improved wetting ability, NF@P-rGO-10 wt% boron nitride (BN) microsheets/epoxy composites could be fabricated and have a further higher thermal conductivity of 0.71 W m −1 K −1 . We believe the use of P-rGO as a novel surface modifier and the following liquid polymer drop-wetting could be an effective method to obtain novel and outstanding metal foam/polymer composites.
研究领域:
材料科学
·
高分子复合材料
·
热管理材料
·
表面与界面工程
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高影响因子
POLYMER BULLETIN
·
2014
·Vol. 71
·期 11
·2923-2944
·
IF 1.491
Yan Huiqiong,Chen Xiuqiong,Wu Tiantian,Feng Yuhong,Wang Chunxiu,Li Jiacheng,Lin Qiang
The surface modification with poly(methyl hydrosiloxane) (PMHS) using a grinding method as a pesticide carrier had been successfully achieved. The characteristics of the modified kaolin were represented by Fourier transform infrared, X-Ray diffraction, BET specific surface area measurements, laser particle size analysis, transmission electron microscopy and contact angle measurement. Subsequently, immobilization of acetamiprid onto clay’s surface was carried out by means of freeze-drying technology. And the drug-loaded clays were encapsulated in alginate-chitosan composite beads by extrusion into calcium chloride solution. The composite beads showed regularly spherical shapes and uniform sizes with diameters of 1.44 ± 0.24–1.75 ± 0.19 mm. The immobilization and release of acetamiprid were carried out to examine the effect of the modified kaolin on the properties of the composite bead. The results showed that the intensive force of superfine pulverization during the grinding process was effective to increase the specific surface areas of the modified kaolin with particle size reduction. The modified kaolins as promising carrier materials had improved the drug loading rate and encapsulation efficiency from 4.15 and 42.01 % for alginate-chitosan composite beads to 6.02 and 82.95 %, which were higher than 4.33 and 54.29 % for SA-CS-kaolin composite beads, respectively. The controlled-release formulation containing the modified kaolin had shown slow and sustained release properties to promote the efficient use of organic pesticide to reduce pollution effect on the environment.
研究领域:
材料科学
·
农业化学
·
药物递送系统
·
环境友好材料
·
粘土矿物加工
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DOI
高影响因子
IONICS
·
2019
·Vol. 25
·期 10
·4567-4576
·
IF 2.289
Xu Chun-Sheng,Yu Hai-Tao,Guo Chen-Feng,Xie Ying,Ren Ning,Yi Ting-Feng,Zhang Guo-Xu
To improve the stability and performance of the cathode materials, an ionic conductor layer was coated successfully on the surface of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 (LMNC) microspheres. The structural analysis confirmed that LiV 3 O 8 coating did not change the basic structure of LMNC, and all obtained materials are solid solutions with a good-layered structure and a good crystallinity. The microscopy measurement showed that the thickness of the coating layer for the LV-3 sample is about 2.5 nm. This appropriate layer is helpful for improving the surface stability of LMNC and the diffusion of lithium, leading to an obvious enhancement of the electrochemical performance. Our result confirmed that the average discharge specific capacities for LV-3 sample at 0.1 C, 0.2 C, 0.5 C, 1 C, and 3 C are respectively 265.9, 219.1, 188.0, 156.3, and 121.5 mAh g −1 , which are much larger than the values of other samples. After 50 cycles at a 1 C rate, the capacity retentions for different samples are 60.7%, 74.0%, 87.6%, and 70.4%, indicating that LV-3 sample exhibits the best performance. Furthermore, EIS measurements showed that the diffusion coefficient for LV-3 sample is calculated to be 1.26 × 10 −15 cm 2 s −1 , which is also the largest value among all considered samples. Our experiments identified that coating an ionic conductive layer on the cathode material surface will significantly improve their rate capacity and cycling stability.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态离子学
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DOI
高影响因子
MONATSHEFTE FUR CHEMIE
·
2014
·Vol. 146
·期 3
·441-447
·
IF 1.347
Li Longfei,Chen Lin,Liu Weifeng,Yang Yongzhen,Liu Xuguang,Chen Yongkang
5-Fluorouracil surface-imprinted thermosensitive magnetic microspheres were prepared by using Fe 3 O 4 -encapsulating carbon microspheres as cores, N -isopropylacrylamide as thermosentitive monomer, ammonium persulfate as initiator, N , N ′-methylenebisacrylamide as crosslinker, and 5-fluorouracil as template molecule. The formation of these hybrid microspheres was verified by field emission scanning electron microscopy, transmission electron microscopy, Fourier transformation infrared spectroscopy, thermogravimetry, and dynamic light scattering. The results of the latter measurements show that the as-synthesized microspheres have a hydrodynamic diameter of 326 nm with the lower critical solution temperature of around 43 °C. The obtained microspheres are magnetic and show good potential for controlled loading and release of 5-fluorouracil. Graphical abstract
研究领域:
药剂学
·
纳米医学
·
肿瘤治疗
·
高分子材料科学
·
靶向给药系统
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DOI
高影响因子
IONICS
·
2021
·Vol. 27
·期 12
·5037-5042
·
IF 2.817
Wang Yinwei,Huang Pengfei,Li Chunfeng
Rational design of host materials for element sulfur is critical in the lithium-sulfur batteries to stabilize the polysulfide, which could migrate from the cathode to the anode, leading to the so-called shuttle effect. Herein, we develop a method to prepare the suitable sulfur host materials for the lithium-sulfur batteries. The manganese dioxide nanospheres are successfully prepared and designed as sulfur host in the lithium-sulfur batteries. The as-prepared manganese dioxide/S composites could be formed flexible and self-supported electrode without the current collector. Due to the presence of the manganese dioxide/S composites, the lithium-sulfur batteries exhibit superior electrochemical performance, including high specific capacity, stable cycling performance, and excellent rate performance.
研究领域:
电化学
·
能源材料
·
纳米材料
·
储能技术
·
先进电池
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DOI
高影响因子
GOLD BULLETIN
·
2015
·Vol. 48
·期 3
·153-159
·
IF 1.59
Gao Haihong,Xiang Weidong,Ma Xin,Ma Li,Huang Yunyun,Ni Huibin,Shi Xingfei,Chen Guixiang,Liang Xiaojuan
Gold nanoparticles (Au NPs) doped monolithic and transparent sodium borosilicate glass has been synthesized by both sol-gel and atmosphere control heat treatment methods. Fourier transform infrared (FTIR) spectra in the wavenumber range of 400 to 4000 cm −1 were applied to collect variation information of surface groups of the samples in the sintering process. The microstructure of Au NPs in the glass was characterized by means of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). Meanwhile, the linear optical properties of the glass were analyzed by UV-vis spectrometer between the wavelength of 300 and 1000 nm, and a broad absorption band around 600 nm was observed. The third-order nonlinear optical properties of the glass were investigated by using Z-scan technique at the wavelength of 800 nm, pulse duration of 190 fs, and repetition rate of 20 Hz. The glass showed saturable absorption and self-focusing nonlinear refraction, and the optical nonlinear susceptibility χ
(3) was estimated to be 1.7 × 10 −14 esu, with the single-pulse energy of 1 μJ.
研究领域:
材料科学
·
纳米光子学
·
光学材料
·
非线性光学
·
溶胶-凝胶技术
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DOI
高影响因子
IONICS
·
2018
·Vol. 24
·期 12
·3805-3813
·
IF 2.347
Zhang Nan,Zhang Ai-ling,Liu Qi-fang,Zhang Meng,Li Qiu,Li Fang-fang
A series of solid polymer electrolytes (SPEs) based on poly (ethylene oxide)/polylactic acid (PEO/PLA) with liquid crystal ionomer (LCI) intercalated montmorillonite (MMT) nanocomposites (LCI-MMT) has been prepared by solution blending method. The effects of LCI-MMT on the structural, crystallization, thermal, and ionic conductivity properties of solid polymer electrolytes have been analyzed. It is demonstrated that the incorporation of LCI-MMT into the blend suppressed the crystallinity of PEO and increased the crystallinity of PLA. The maximum ionic conductivity is found to be in the range of 1.05 × 10 −5 S/cm for 0.5 wt% LCI-MMT, which is higher than that of the LCI-MMT-free polymer electrolyte (5.36 × 10 −6 S/cm) at room temperature.
研究领域:
材料科学
·
高分子科学
·
电化学
·
纳米复合材料
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DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2022
·Vol. 128
·期 4
·355
·
IF 2.983
Zhang Yixuan,Sun Li,Yu Zhichao,Nie Zhongquan,Cao Ensi
LaFeO 3 nanoparticles were synthesized by a sol–gel method and directly mixed with commercial PANI powders to form a series of PANI–LaFeO 3 nanocomposites according to the mass ratio PANI to LaFeO 3 as 1%, 3%, and 5%. XRD and SEM results reveal that the LaFeO 3 nanoparticles in the orthorhombic crystal structure are distributed on the surface of the PANI bulk. The nanocomposites-based sensors showed better acetone sensing performance than the pure LaFeO 3 , which was ascribed to the increased amount of oxygen adsorbed on the surface of LaFeO 3 nanoparticles and the enhanced modulation of the internal carrier transfer within the nanocomposites. The sensor based on the PANI–LaFeO 3 nanocomposite with a mass ratio of 3% showed the highest response (36.6) to 100 ppm acetone with the best selectivity against methanol, ammonia, and ethylene glycol at the prime working temperature of 120℃. Therefore, the PANI–LaFeO 3 nanocomposite is a promising acetone sensing material with low energy consumption.
研究领域:
材料科学
·
传感器与仪器
·
纳米技术
·
气体传感
·
无机化学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 24
·10690-10700
·
IF 2.302
Wang Hua,Xiao Hao,Lu Yonggen,Jiang Junqi
The influence of BN on the mechanical properties of carbon fibers was investigated. It is found that the Young’s modulus of the derived carbon fibers becomes higher with BN amounts increasing through heat treatments at 1600–2350 °C, while the tensile strength increases at 1600 and 2000 °C and decreases at 2200 and 2350 °C with BN amounts increasing. Carbon fibers’ modulus and strength are increased by 6.6 and 7.4 % at maximum, respectively. It can be interpreted that fiber modulus is mainly determined by the preferred orientation of graphene planes and the shear modulus between them, while the strength of carbon fibers strength is determined by not only the two factors but also defects. Through X-ray diffraction, Raman spectra, and scanning electron microscope analysis, it is noted that BN catalysis enhances the preferred orientation of graphene planes and makes little change on the shear modulus but generates more defects above 2000 °C for fierce reaction.
研究领域:
材料科学
·
碳材料
·
高分子工程
·
纳米复合材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）