RSC Advances
·
2022
·Vol. 12
·期 19
·11715-11721
·
IF 4.036
Baokang Zou,Yipeng Zhan,Xiuli Xie,TongTong Zhang,Runkai Qiu,Fangming Zhu
Two salalen titanium(IV) complexes ((H-salalen)TiCl2 and (F-salalen)TiCl2) containing hydrogen and fluorine respectively on the phenolate ring close to the imine were synthesized for the copolymerization of ethylene with 1-octene to prepare poly(ethylene-co-1-octene) in the presence of methylaluminoxane (MAO). The (F-salalen)TiCl2/MAO showed higher catalytic activity and better copolymer characteristics such as a higher molecular weight, narrower molecular weight distribution, and higher 1-octene incorporation than (H-salalen)TiCl2/MAO, which revealed that the electron-withdrawing conjugated effect introduced by fluorine substituents led to improvements on catalytic performance and thermal stability. The influences of copolymerization conditions including temperature, Al/Ti molar ratios and comonomer feed ratios on the copolymerization behavior of (F-salalen)TiCl2/MAO and the copolymer microstructure were investigated in detail. Under the activation of MAO, the (F-salalen)TiCl2 could produce ultrahigh molecular weight poly(ethylene-co-1-octene) with 1-octene incorporation ratios in the range of 0.9–3.1 mol% and exhibit relatively high activity. It could be inferred that long ethylene sequences in the copolymer were segregated by the isolated 1-octene units based on the 13C NMR characterization of the copolymer. Moreover, the thermal properties and crystallization of copolymers were determined by DSC and XRD and correlated to the ethylene sequence length distribution. The reactivity ratios calculated by the triad distribution in 13C NMR revealed the random comonomer distribution in the copolymer chain.
研究领域:
高分子化学
·
配位聚合
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催化化学
·
材料科学
·
高分子物理
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2017
·
IF 4.075
Guangshun Wu,Lei Chen,Li Liu
Effects of silane and silica enrichment of carbon fibers (CFs) on interfacial properties of methylphenylsilicone resin (MPSR) composites were investigated. CFs were oxidized, grafted with 3-aminopropyltriethoxysilane (APS) and then modified with silica nanoparticles prepared by the sol-gel polymerization of tetraethoxysilane (TEOS). Chemical structures of CFs were characterized by confirming the successful grafting. Scanning electron microscopy (SEM) showed a uniform distribution of silica nanoparticles on the CFs surface. The interlaminar shear strength (ILSS) and impact toughness of silanized CF (CF-Siloxane) composites were 12.05% and 7.46% higher than those of untreated composites. However, ILSS and impact toughness of the hybrid fiber (CF/Si) composites obtained from the hydrolysis of different concentrations TEOS improved significantly, especially for grafting silica enrichment with the TEOS concentration of 0.05 mol/L (CF/Si0.05), increasing 45.64% in ILSS and 29.59% in impact properties. Moreover, the hydrothermal aging resistance was also improved greatly. Meanwhile, functionalization processes did not decrease fiber tensile strength .
研究领域:
复合材料科学
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高分子材料
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表面改性
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界面工程
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材料化学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Hongyuan Zhao,Huina Ma,Xiaoguang Li,Binbin Liu,Runqiang Liu,Sridhar Komarneni
We report a simple and highly efficient preparation of nanocomposite of halloysite (Hal) nanotubes/multi-walled carbon nanotubes (Hal-MWCNTs) and its electrochemical sensor application for the determination of methyl parathion (MP). The phase structure and surface morphology of the Hal-MWCNTs nanocomposite were confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectra. According to the electrochemical tests, the fabricated glassy carbon electrode (GCE) sensor with Hal and multi-walled carbon nanotubes showed excellent MP determination performance because of the synergistic effect of Hal and multi-walled carbon nanotubes . The Hal-MWCNTs/GCE sensor exhibited a relatively low detection limit of 0.034 μM in the linear range of 0.5–11 μM. When used for the determination of MP in real samples, the Hal-MWCNTs/GCE sensor showed good detection effect with satisfactory relative standard deviation (RSD) of 2.46 to 3.08% and recoveries of 98.8 of 101.8%. This work indicated that the nanocomposite of Hal-MWCNTs when coated on GCE is useful for the fabrication of high-performance MP electrochemical sensor.
研究领域:
分析化学
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环境监测
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纳米材料科学
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电化学
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食品安全
·
毒理学
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2021
·
IF 7.328
Hongyuan Zhao,Bo Li,Runqiang Liu,Yuqi Chang,Hongliang Wang,Lin Zhou,Sridhar Komarneni
Herein, a cost-effective and scalable ultrasound assisted approach was proposed to prepare the nanocomposite of halloysite nanotubes/zirconia/carbon black (Hal/ZrO 2 /CB), which was used to fabricate a novel electrochemical sensor for the highly sensitive determination of methyl parathion (MP). In the Hal/ZrO 2 /CB nanocomposite, Hal with large specific surface area and numerous active sites could enhance the adsorption capacity and accelerate the redox reaction of MP; ZrO 2 nanoparticles with high affinity toward the phosphate group could contribute to good recognition performance for MP; CB nanoparticles with good dispersibility formed an interconnected pearl-chain-like conductive network. Benefitting from the synergistic effect of the three components, the Hal/ZrO 2 /CB/GCE (glassy carbon electrode) sensor showed a remarkably low detection limit of 5.23 nM in a good linear MP detection range of 0.01–10 μM. The Hal/ZrO 2 /CB/GCE sensor possessed a pretty decent practicality with satisfactory RSD and recovery results for the determination of MP in peach, pear, and apple juices. Therefore, the Hal/ZrO 2 /CB/GCE sensor has important implication on the quite sensitive detection of MP.
研究领域:
分析化学
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纳米科学与技术
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环境监测
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食品安全
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电化学传感
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农药残留检测
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Shuming Liu,Shuqi Liu,Qian Wang,Zhou Zuo,Xidong Liang
Superhydrophobic surfaces, such as lotus leaves, have attracted significant attention because of their excellent performance and potential application value. However, the micro-nano hierarchy on superhydrophobic surfaces is often vulnerable and easily broken from mechanical stress or chemical corrosion, which greatly inhibits its practical application and long-term service. This study presents a low-cost and scalable superhydrophobic coating based on an interpenetrated polymer network of polydimethylsiloxane (PDMS) and epoxy resin . The composite polymer matrix exhibits mechanical robustness as derived from the epoxy resin and low surface energy as derived from the PDMS. The superhydrophobic coating is obtained by dispersing fluoroalkyl-silane-modified SiO 2 in the solution containing the composite polymer . The multi-level hierarchical structure of SiO 2 aggregations and their strong bonding with the composite polymer gives the coating outstanding mechanical durability while maintaining superhydrophobicity after multiple cycles of sandpaper abrasion, tape peeling, and water impact tests. The chemical inertness of all components ensures its chemical stability, and the surface shows super repellency to strong acids and alkaline liquids (pH = 0–14). The coating also has excellent self-cleaning properties, which has potential applications in various industrial fields.
研究领域:
材料科学
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高分子化学
·
表面工程
·
涂层技术
·
功能材料
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2013
·Vol. 15
·期 32
·6368-6373
·
IF 3.879
Shuling Xu,Lei Wang,Haibo Li,Qiaoli Yue,Rui Li,Jifeng Liu,Xiaohong Gu,Shuqiu Zhang
Novel three-dimensional Ag nanoflowers (3DAN) were successfully synthesized through a facile Cu2+ mediated solution method using N,N-dimethylformamide (DMF), which serves as both a reducing agent and a solvent at room temperature. It was found that the introduction of a trace amount of Cu2+ could greatly slow the rate of the Ag+ reaction and thus this process effectively reduced the growth speed of Ag nanoparticles allowing 3DAN to be formed. The mechanism underlying the self-assembly process and shape evolution of 3DAN were systematically investigated by varying reaction time. X-Ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were used to characterize the structure and morphology of the obtained products. X-Ray photoelectron spectroscopy (XPS) was used to assess the chemical state and surface composition of the 3DAN. UV-vis absorption spectra of the products collected from the reaction solution at various stages were taken to study their optical properties. In the measurement of surface-enhanced Raman scattering using rhodamine 6G (R6G) as the probe, the 3DAN exhibited a significant enhancement factor, indicating their potential applications in biosensing and nanodevices.
研究领域:
纳米医学
·
生物传感
·
材料科学
·
胶体化学
·
分子影像学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2013
·Vol. 51
·期 7
·1559-1564
·
IF 3.543
Xiao-Hui Liu,Yun-Hai Yu,Di Jia,Bo-Wen Cheng,Fei-Jun Zhang,Hui-Na Li,Peng Chen,Shan Xie
Single electron transfer living radical polymerization of methyl methacrylate catalyzed by the in situ prepared Cu(0) at ambient temperature was first examined using various metallic powders, including Zn(0), Ni(0), Mg(0), and Fe(0). Importantly, the polymerization initiated with Ni(0)/EBiB/CuBr 2 /PMDETA system exhibited optimal living/controlled nature and generated polymers with polydispersity index as low as 1.04 for 75.27% conversion and controlled molecular weights close to theoretical ones. A wide of range of Cu(II) salts were also investigated as catalyst sources instead of CuBr 2 . The recycling of Ni(0) was very convenient due to its magnetic property, which enables its extensive application. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
研究领域:
高分子化学
·
材料科学
·
催化化学
·
有机合成
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2018
·
IF 1.742
Xuehua Zhang,Liang Yu,Wei Zhang,Fangren Hu,Yongjin Wang
PS microspheres emulsions with different PS diameters of 207 and 378 nm were prepared by using an emulsifier-free polymerization method. A novel secondary self-assembly method which combined the spin coating and the lifting-up method was used to prepare the close-packed PS MCC films. During the process, the PS MCC film was firstly assembled on a glass substrate by a spin coating technique. Secondly, the obtained PS MCC film was transferred on the air-water interface by immersing the PS glass substrate in water using a dip-coater. Thirdly, the floating close-packed PS MCC films on the air-water interface was transferred to a new glass substrate by using a lifting-up method. During the spin-coating and the self-assembly process, some SDS solution was added in the PS films to improve the uniformity of the PS layer. Effects of the spin-coating speeds, the SDS solution concentration and the lifting-up rates on the morphology of PS MCC films have been discussed. Scanning electron microscopy was used to observe the morphological properties of the PS colloidal crystal films. Results indicate that a relatively close-packed and large scale PS MCC films can be obtained when the spinning speed is 2000 rpm for 60 s, the SDS solution concentration is 2 wt% and the lifting-up rate is 2 mm/min. Furthermore, the polydimethylsiloxane soft mold was replicated from the-fabricated PS MCC films and was then imprinted onto the photosensitive hybrid film under UV-irradiation and thus the micro-lens arrays built in the photosensitive hybrid sol–gel film were obtained.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2024
·
IF 3.7
Xiaofei Xu,Xiaolong Li,Zhi Li,Da Zhang
An experimental study of single carbon dioxide (CO 2 ) bubbles ascending in aqueous solutions of carboxymethyl cellulose (CMC) is performed as a means to obtain further understanding of the rising behavior and mass transfer of soluble bubbles in shear-thinning non-Newtonian fluids. High-speed photography and digital image processing technique are employed to quantify the characteristic parameters of the bubble rising process. The rising behavior of single CO 2 bubbles in a Newtonian fluid (tap water) is measured as a reference. It has been found that the rheology of the liquid phase significantly influenced the rising behavior of the bubbles. In CMC aqueous solutions, CO 2 bubbles mostly followed a straight rising path characterized by increasing aspect ratio and decreasing vertical velocity. Increase in initial bubble size led to bubble deformation in less concentrated CMC aqueous solutions which resulted in an irregular rising path. The evolution of bubble equivalent diameter can be mainly divided into two stages: a fast reduction stage followed by a slow one. Meanwhile, the variation of liquid-side mass transfer coefficient k L of CO 2 bubbles in tap water and CMC aqueous solution with different weight percentages is discussed. The mobility of gas-liquid interface is considered to have significant impact on gas-liquid mass transfer. A dimensionless correlation considering the rheology of the liquid phase is proposed to describe the evolution of the motion and deformation of single soluble CO 2 bubbles in infinite stagnant shear-thinning non-Newtonian liquids.
研究领域:
流体力学
·
化学工程
·
多相流
·
传质过程
·
非牛顿流体动力学
·
气泡动力学
·
环境工程
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 12
·期 6
·5421-5430
·
IF 1.5
Yangyang Xi,Peng Zhang,Haining Zhang,Zhaohui Wan,Wenmao Tu,Haolin Tang
Composite membrane separators are fabricated by coating one side of microporous polyethylene membrane with poly(methyl methacrylate) modified titanate nanoparticles that are synthesized through emulsifier-free emulsion polymerization of methacrylate-functionalized titanate nanoparticles. The formed composite membrane separators exhibit great thermal-shrinking resistance due to the introduction of thermal resistant titanate nanoparticles. After immersed into electrolyte solution, the swelling poly(methyl methacrylate) microspheres leads to the formation of gel electrolyte, thus stabilizing the electrolyte. Moreover, the porous structure of the coated layer can facilitate the swelling of electrolyte and the transport of lithium ions. The thus-assembled lithium ion battery shows an improved cycle performance and rate capability.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子纳米复合材料
·
电池技术
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Yuanfeng Pan,Jingchun Wang,Pingxiong Cai,Huining Xiao
In this work, the stepwise synthesis of interpenetrating polymer network (IPN) strategy was developed in an attempt to fabricate novel hydrogels consisting of sugarcane bagasse cellulose (SBC), carboxymethylcellulose (CMC) and poly (N-isopropylacrylamide) (PNIPAm) as a dual-responsive drug carrier. The pretreated and dissolved SBC was pre-crosslinked using epichlorohydrin in the presence of CMC, followed by in-situ free-radical polymerization of NIPAm in the presence of N,N′-Methylene-bis(acrylamide) as a crosslinking agent. The carboxyl groups in CMC and PNIPAm chains rendered the resulting hydrogel pH and thermal responsive. The results from scanning electron microscopy, infrared spectroscopy , thermogravimetric analysis and mechanical property testing demonstrated the successful formation of the IPN with proper structure and mechanical strength . The swelling experiments at different temperatures and pH showed the dual–sensibility of the hydrogels. Moreover, bovine serum albumin (BSA) was used as a model drug and loaded in the hydrogel; and the drug release behavior was revealed in phosphate buffer solution (PBS) and simulated gastric fluid (SGF). The results indicated that the dual-responsive IPN hydrogel is of great potential for the controlled release of drug.
研究领域:
高分子材料
·
药物递送
·
生物医学工程
·
智能响应材料
·
药剂学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2018
·
IF 3.12
Fan Bu,Baoyu Gao,Qinyan Yue,Xue Shen,Wenyu Wang
Coagulation–ultrafiltration (C–UF) is widely used for surface water treatment. With the removal of pollutants, the characteristics of organic matter change and affect the final treatment efficiency and the development of membrane fouling . In this study, we built a dynamic C–UF set-up to carry out the treatment of micro-polluted surface water, to investigate the characteristics of dissolved organic matter from different units. The influences of poly aluminum chloride and poly dimethyldiallylammonium chloride (PDMDAAC) on removal efficiency and membrane fouling were also investigated. Results showed that the dosage of PDMDAAC evidently increased the UV 254 and dissolved organic carbon removal efficiencies, and thereby alleviated membrane fouling in the C–UF process. Most hydrophobic bases (HoB) and hydrophobic neutral fractions could be removed by coagulation. Similarly, UF was good at removing HoB compared to hydrophilic substances (HiS) and hydrophobic acid (HoA) fractions. HiS and HoA fractions with low molecule weight accumulated on the surface of the membrane, causing the increase of transmembrane pressure (TMP). Membrane fouling was mainly caused by a removable cake layer, and mechanical cleaning was an efficient way to decrease the TMP.
研究领域:
环境工程
·
水处理技术
·
膜分离
·
有机地球化学
·
给水处理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）