JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 54
·期 3
·368-380
·
IF 3.113
Jingang Li,Yixin Xiang,Sixun Zheng
In this contribution, we reported the synthesis of a hyperbranched block copolymer composed of poly(ε-caprolactone) (PCL) and polystyrene (PS) subchains. Toward this end, we first synthesized an α-alkynyl- and ω,ω′-diazido-terminated PCL- b -(PS) 2 macromonomer via the combination of ring-opening polymerization and atom transfer radical polymerization. By the use of this AB 2 macromonomer, the hyperbranched block copolymer ( h -[PCL- b -(PS) 2 ]) was synthesized via a copper-catalyzed Huisgen 1,3-dipolar cycloaddition (i.e., click reaction) polymerization. The hyperbranched block copolymer was characterized by means of 1 H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Both differential scanning calorimetry and atomic force microscopy showed that the hyperbranched block copolymer was microphase-separated in bulk. While this hyperbranched block copolymer was incorporated into epoxy, the nanostructured thermosets were successfully obtained; the formation of the nanophases in epoxy followed reaction-induced microphase separation mechanism as evidenced by atomic force microscopy, small angle X-ray scattering, and dynamic mechanical thermal analysis. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 368–380
研究领域:
高分子化学
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材料科学
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纳米结构功能材料
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聚合物自组装
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热固性树脂改性
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2018
·
IF 2.732
Qinghua Yang,Benxue Jiang,Shuilin Chen,Yiguang Jiang,Pande Zhang,Jun Wang,Shiqing Xu,Long Zhang
Al 2 O 3 : Er 3+ /Yb 3+ transparent ceramics codoped with Zn 2+ ions with intense upconversion and near infrared emission were prepared by conventional solid-state reaction and vacuum and hot isostatic pressing sintering. The effects of Zn 2+ incorporation to the structure, transparent, upconversion and NIR luminescence were discussed in detail. The as prepared Al 2 O 3 ceramics exhibited a total transmittance of ~ 75% in infrared regions (800–3300 nm) and ~ 50% in visible regions (500–800 nm). Under the excitation of a 980 nm laser diode , the as prepared Al 2 O 3 ceramics displayed two tense upconversion emission peaks of a green one centered at 550 nm and a red one centered at 660 nm and a tense near infrared emission peak centered at 1.532 µm, characteristic of Er 3+ emission. Compared with Er 3+ /Yb 3+ doped only, Zn 2+ codoped Al 2 O 3 :Er 3+ /Yb 3+ transparent ceramics showed higher upconversion and near infrared emission of ~ 11 times and ~ 4 times, respectively. The enhancement mechanism due to incorporation of Zn 2+ ions was also discussed in detail.
研究领域:
材料科学
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光学材料
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无机非金属材料
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发光材料
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陶瓷工程
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DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2018
·
IF 2.179
Linlin Xu,Dong Chen,Hui Liu,Jun Yang
Structural conversion using core-shell silver (Ag)-platinum (Pt) nanoparticles as starting materials is a promising way to produce nanocomposites consisting of silver sulfide (Ag 2 S) and hollow Pt nanostructures (Ag 2 S-hPtNCs). However, the mechanism behind the structural conversion process is yet to be understood. In this study, we use transmission electron microscope (TEM) as a typical tool to characterize the products formed in different structural conversion processes, and interpret the experimental observations by proposing mechanisms behind the reactions between core-shell Ag-Pt nanoparticles and sulfur precursors from different sources. We then design additional experiments to rationalize the formation mechanism we proposed. The mechanistic understanding of the structural conversion from bimetallic core-shell nanostructures to heterogeneous nanocomposites may extend the fabrication of heterogeneous nanocomposites for a given technological application.
研究领域:
纳米材料科学
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无机化学
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纳米医学
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生物材料
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转化医学
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DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 52
·27259-27266
·
IF 3.708
Libin Yang,Feng Xin,Junzhong Lin,Zhuang Zhuang,Rui Sun
In this study, a hydrothermal synthesis was developed to prepare a thin titanium silicalite-1 catalyst layer in the internal channels of the honeycomb cordierite support, which was used in a continuous heterogeneous reaction. The as-prepared thin TS-1 catalyst layer was characterized by SEM, XRD, UV-vis and ATR-FTIR methods. Multiple hydrothermal syntheses were used for controlling the crystalline growth to optimize catalytic activity and lifetime. Moreover, a monolithic TS-1/cordierite reactor with external looping was utilized to investigate the characteristics of the continuous heterogeneous ammoximation reaction without the organic solvent tert-butanol (TBA). The reaction results showed that the conversion of cyclohexanone and selectivity of oxime approached more than 0.96 and 0.98, respectively. When compared with the reaction using TBA as the reaction solvent, the activity of the monolithic TS-1/cordierite showed no differences except for a longer lifetime.
研究领域:
化学工程
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催化化学
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材料科学
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工业化学
·
绿色化学
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DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 30
·期 11
·2781-2789
·
IF 2.162
Tingjun Zhong,Richard J. Mandle,John W. Goodby,Lanying Zhang,Cuihong Zhang
In this work, the thiol-ene click reaction is employed to fabricate polymer-dispersed liquid crystal (PDLC) films by photoinitiated polymerization. The PDLC films are prepared by systematic variation of key conditions: variety and content of -ene monomer, liquid crystal (LC) content, curing time, and curing light intensity. We find that both the morphologies and electro-optic properties of these films are adjustable. When increasing the length of alkyl main chain of -ene monomers, the driving voltages reduce, but in turn, the contrast ratio decreases. Increasing -ene monomer content raises the driving voltages as well as the response time, and the increase of LC content lowers the driving voltages but has a negative effect on the contrast ratio. The changes to the curing conditions (both curing time and UV light intensity) can be used to modify the driving voltages, response time, and contrast ratios of PDLC films. These comparative studies will elucidate new insights in commercial applications of intelligent PDLC films.
研究领域:
材料科学
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高分子化学
·
软物质物理
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光电功能材料
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智能材料
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DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Xian Wang,Zuju Ma,Lulu Chai,Leqiong Xu,Ziyi Zhu,Yue Hu,Jinjie Qian,Shaoming Huang
Growing demand for clean and renewable energy resources has sparked intensive research on the development of an effective strategy to prepare non-noble metal electrocatalysts for oxygen evolution reaction (OER). Herein, we report a new type of N-doped carbon coated CoP particle/carbon nanotube composite (CNT-NC-CoP) has been synthesized by in situ nucleation and growth of ZIF-67 nanoparticles onto carbon nanotubes, which subsequently is treated with carbonization and phosphorization. Unique hierarchical structure endows as-obtained CNT-NC-CoP with high specific surface area , abundant exposed active sites, quick ion diffusion path , and good electrical conductivity , thus exhibiting the highest electrocatalytic capability with the low overpotential of 251 mV at the current density of 10 mA cm −2 and remaining long-term durability (overlapping LSV curve after 10 h). Besides, density functional theory (DFT) calculations reveal that CoOOH/graphene charged surfaces are more effective for facilitating intermediates adsorption and improving the corresponding catalytic activity .
研究领域:
材料化学
·
电化学
·
纳米材料科学
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能源催化
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功能材料
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计算材料学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 35
·29638-29645
·
IF 3.289
Xin Ge,Xinzhi Chen,Chao Qian,Shaodong Zhou
Ullmann type C–N coupling reaction catalyzed by copper(I) with D-glucosamine derivatives as promoters was studied by means of combined experimental/theoretical investigation. The catalytic role of D-glucosamine was addressed. In contrast with previous speculations, the amino group may not count in the catalytic cycle in which the oxidative addition/reductive elimination mechanism works. Experimental results are in good agreement with theoretical findings. Extensive work indicates the wide applicability of the C–N coupling strategy exploited in this work.
研究领域:
有机化学
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催化化学
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药物化学
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计算化学
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合成方法学
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生物正交化学
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金属有机化学
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DOI
高影响因子
Advanced Healthcare Materials
·
2024
·Vol. 14
·期 1
·2402272
·
IF 10
Hongwei Zhang,Linfu Chen,Qian Chen,Qiufang Chen,Jun Zhou
Tirapazamine (TPZ), an antitumor prodrug, can be activated in hypoxic environment. It specifically targets the hypoxic microenvironment of tumors and produces toxic free radicals. However, due to the tumor is not completely hypoxic, TPZ often fails to effectively treat the entire tumor tissue, resulting in suboptimal therapeutic outcomes. Herein, a low pathogenic Escherichia coli TOP10 is utilized to selectively colonize tumor tissues, disrupt blood vessels, and induce thrombus formation, leading to the expansion of hypoxic region and improving the therapeutic effect of TPZ. Additionally, a thermosensitive hydrogel is constructed by Pluronic F-127 (F127), which undergoes gelation in situ at the tumor site, resulting in sustained release of TPZ. To monitor the therapeutic process, it is genetically modified TOP10 by integrating the bioluminescent system luxCDABE (TOP10-Lux). The bioluminescent signal is associated with tumor hypoxia enhancement and thrombus formation, which is beneficial for therapeutic monitoring with bioluminescence imaging. In the murine colon cancer model, the TOP10-Lux combined with TPZ-loaded F127 hydrogel effectively suppressed tumor growth, and the treatment process is efficiently monitored. Together, this work employs genetically modified TOP10-Lux to enhance the therapeutic efficacy of TPZ and monitor the treatment process, providing an effective strategy for bacteria-based tumor-targeted chemotherapy and treatment monitoring.
研究领域:
肿瘤学
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微生物治疗
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分子影像学
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药物递送
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生物材料
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转化医学
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合成生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Hongjun Zang,Yimo Feng,Jing Lou,Kai Wang,Changchun Wu,Zhipeng Liu,Xi Zhu
Ionic liquids have shown good catalytic performance and been widely used in the biomass conversion process due to their unique properties, including environmental friendship, low toxicity, and simple preparation. In this work, a series of novel piperidinium-based ionic liquids were synthesized under mild conditions via a simple protonation reaction or nucleophilic substitution reaction. Among them, 4,4′-(propane-1,3-diyl)bis(1-(carboxymethyl)piperidin-1-ium) chloride ([PDCMPi]Cl) displayed the best catalytic performance. The highest yield (42.81 %) of 3A5AF from NAG was obtained after reacting in N-methyl-pyrrolidone (NMP) in the presence of piperidinium-based ionic liquids at 180 °C for 20 min under normal atmospheric conditions. Additionally, ionic liquid [PDCMPi]Cl showed good catalytic activity in six repeated catalytic runs. Meanwhile, a possible reaction pathway was also proposed on the basis of the results of NMR spectra.
研究领域:
催化化学
·
绿色化学
·
生物质能源
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有机合成
·
离子液体化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 125
·期 4
·2867-2873
·
IF 1.289
Yehai Yan,Na Lu,Jian Cui,Jinfang Zhang
A new fluorescent copolymer, poly(1-vinylimidazole- co -(1-pyrene) methyl 2-methyl-2-propenote) (VI- co -PyMMP), has been designed and synthesized by a free-radical copolymerization of VI and PyMMP as well as characterized using ultraviolet (UV), Fourier transform infrared spectroscopy (FTIR), 1 H NMR, and fluorescence spectroscopies. The monomer reactivity ratios are determined by two methods of Fineman-Ross ( r 1 = 0.28 ± 0.04 for VI, r 2 = 1.32 ± 0.11 for PyMMP) and Kelen-Tüdös ( r 1 = 0.23 ± 0.05, r 2 = 1.22 ± 0.12). Based on the reactivity ratios, the monomer sequence lengths and Q and e for PyMMP monomer are further calculated. The results suggest that the copolymerization of VI and PyMMP is a nonideal copolymerization without an azeotropic point (i.e., r 1 < 1, r 2 > 1 and r 1 r 2 < 1) and has a low alternation tendency. The conclusions drawn in this work may not only direct the later synthesis of the copolymers but also enrich the database of free-radical copolymerization. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
研究领域:
高分子化学
·
功能高分子
·
荧光材料
·
聚合物合成
·
材料化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·Vol. 43
·期 45
·20712-20720
·
IF 4.229
Biyao Jin,Yiqi Li,Lianhua Zhao
Bimetallic PdV/C nanoparticles have been synthesized by phase-transfer method for catalyzing the oxygen reduction reaction (ORR) in alkaline electrolytes . PdV/C nanoparticles with different V contents are spherical with a mean diameter of 3–4 nm, and the addition of V expands the lattice parameter of Pd as shown by XRD . XPS analysis indicated the binding energy of Pd 0 3d peak increased by ca. 1 eV. Density functional theory (DFT) calculations results shows d-band center of Pd down-shift after V-doping. Based on the electrocatalytic results, introducing V can improve the catalytic activity for ORR, methanol crossover tolerance and stability. Especially, Pd 4 V/C shows higher initial potential (E onset = 1.027 V), excellent methanol crossover tolerance (98.03% retained) and long-term stability (81.30% retained), which are comparable with Pt/C JM . This work provides a new method of synthesizing PdV/C nanoparticles , which have the potential to be used as the cathode electrocatalysts for fuel cells.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
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燃料电池
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物理化学
·
表面科学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2021
·
IF 4.185
Zhi-Hao Jin,Jin-Tao Chen,Wang Li,Shu-Bao Song,Jiu-Zhong Yang,Zhen-Yu Tian
Owing to significant advantages over traditional biofuels, 2-methylfuran (MF) has arisen extensive interest as next generation biofuels . Atmospheric pressure pyrolysis of a 1:1 blend of MF with a three-component (3C) surrogate jet fuel was conducted in a flow tube using synchrotronphotoionization and molecular beam mass spectrometry techniques within a temperature range of 898–1223 K. Therein, the 3C surrogate fuel consists of 66.2% n-dodecane (NC 12 H 26 ), 18.0% 1,3,5-trimethylcyclohexane (T135MCH) and 15.8% n-propylbenzene (NPB, A1C 3 H 7 ). The detailed kinetic model including 579 species and 3474 reactions was developed via validating against both measured and literature data with reasonable agreement. MF exhibits no obvious influence on the 3C components pyrolysis . However, 3C mixtures play an important roles in MF decomposition: lower initial temperature and different decomposition pathways. In the meantime, n-propylbenzene (NPB) pyrolysis curve in 3C and 3C+MF significantly transfers to low temperature zone after 1000 K in contrast to pure NPB, while smaller change was found in the decomposition curve of n-dodecane. Compared with 3C pyrolysis, 3C+MF blends have less formation of aromatic species and light hydrocarbons except for vinylacetylene (C 4 H 4 ) and acetylene (C 2 H 2 ). Allyl radical (C 3 H 3 ) has significant roles in benzene ring formation. The combination of allyl radical with propargyl radical producing benzene and H radical (aC 3 H 5 + C 3 H 3 = A1 + 2H) has the highest contribution to the benzene formation in both 3C and 3C+MF. Moreover, most of naphthalene (A2) formation is also related to C 3 H 3 radical via reaction: A1CH 2 + C 3 H 3 = A2 + H, rather than via HACA (hydrogen abstraction carbon addition) reaction. Interaction of fuel blends was mainly presented through the common and important sensitive reactions which are much to do with CH 3 and H radicals. The overview of product distribution was investigated by providing comparisons of carbon conversion rates during the pyrolysis of 3C and 3C+MF. These results will be helpful to better understand the pyrolysis properties of MF/jet fuel surrogate blends and could contribute to developing new generation biofuels for aviation.
研究领域:
燃料化学
·
燃烧动力学
·
生物燃料
·
能源化学
·
反应机理
·
质谱分析
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）