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
·
催化化学
·
药物化学
·
计算化学
·
合成方法学
·
生物正交化学
·
金属有机化学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2011
·Vol. 212
·期 21
·2378-2388
·
IF 2.437
Bin Yuan,Xiaohui He,Yiwang Chen,Kaiti Wang
Covalently immobilized silica-supported acetylacetonate dichloride palladium(II) precatalyst is prepared by the reaction of silica particles grafted acetylacetonate ligand further exchange with [Et 4 N] 2 PdCl 4 . The silica-supported catalyst is used in slurry polymerizations of norbornene (NB) to afford a highly productive NB addition polymerization system in combination with B(C 6 F 5 ) 3 cocatalyst. It exhibits productivity of 84 kg of PNB (mol Pd) −1 h −1 at the initial activity, and the catalyst deactivation kinetics in the early stage of polymerization are fitted well by the first-order deactivation kinetics. The obtained vinyl-type polynorbornene is confirmed to be nanosilica hybrid PNB nanocomposite by SEM, TEM with an energy dispersive spectrometer, TGA, and XRD.
研究领域:
高分子化学
·
纳米复合材料
·
催化化学
·
有机金属化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yinwei Fu,Xiaofeng Lei,Huiming Yin,Xizheng Liu
Flexible lithium–air batteries (LABs) with a redox mediator (RM) in the electrolyte demonstrate enhanced round-trip efficiency. However, their cycle performance is unsatisfactory due to severe corrosion of the Li metal anode. Herein, we propose a two step gelatinization strategy to fabricate a gradient RMs (including LiI, TMPD, and DMPZ) gel electrolyte, in which the bare electrolyte gelatinization on the Li surface and then the electrolyte contained RMs sequentially gelled on the formed gel. The RMs mainly distributed at the surface and anchored at the cathode side. By suppressing the shuttle of RMs in the electrolyte and alleviating the passivation of the Li anode, the mid-charging potentials can reach 3.44 and 4.08 V at the 15th cycle with and without the LiI mediator, respectively. The energy efficiency is 63% even at the 150th cycle, whereas the corresponding energy efficiency are only 47% and 51% for the LABs with liquid and normal gel electrolytes, respectively. Moreover, the cycle life of the battery containing the gradient gel electrolyte is three times longer than that with the liquid electrolyte. The gel electrolyte further offers the flexibility of the device, and the laminated cells thus fabricated can readily operate under harsh bending conditions.
研究领域:
电化学
·
能源材料
·
纳米材料
·
界面化学
·
储能技术
·
先进电池
·
功能高分子
·
柔性电子
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2016
·
IF 4.055
Da-fa Yang,Xiang-jun Kong,Dan Gao,Hong-sheng Cui,Ting-ting Huang,Jin-xin Lin
Reactive disperse dyes with mono- and bi-acyl fluoride reactive groups have been synthesized using a simple and convenient method. The structures of these dyes have been defined by 1 H, 13 C and 19 F NMR. The cotton dyeing in supercritical carbon dioxide (Sc CO 2 ) with dyeing temperature varying from 60 °C to 120 °C and time between 1 h and 3 h and with the concentration of 0.5% owf (on weight of fabric) have been studied. Significant improvement of the color fastness of washing and rubbing has been observed owing to the covalent bond formed between the reactive group of dyes and the functional group of cotton fibers . Besides, the dyed fabrics possess favorable fastness properties , indicating the achievement of lower-temperature dyeing of cotton in Sc CO 2 . Additionally, the end products meet the garment dyeing standards as well. A mechanism of dyeing process is tentatively speculated meanwhile.
研究领域:
纺织化学
·
染整工程
·
绿色化学
·
高分子材料与纤维科学
·
环境友好染色技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 16
·22776-22785
·
IF 4.527
Kaidan Wu,Yefeng Feng,Jin Ke,Bingwen Yang,Zhiling Guo,Deping Xiong,Miao He
Graphite nanosheets coated by LiF/SnO 2 composites are designed to obtain a lithium ion anode material with excellent performance. LiF nanoparticles play a significant role in improving the electrochemical performance by inhibiting electrolyte decomposition and providing excess Li sources during cycling. The obtained LiF@SnO 2 @C electrode shows an outstanding capacity of 951.9 mAhg −1 at 0.2 Ag -1 after 370 cycles and excellent long cycling performance of 650.0 mAhg −1 at 1.0 Ag -1 after 930 cycles. First-principles calculations demonstrate that F-doped SnO 2 (−2211.8 eV) has a lower free energy compared to SnO 2 (−1937.4 eV), resulting in a robust composite architecture that gives rise to high cycling stability.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
计算材料学
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 24
·4926-4933
·
IF 1.915
Dejiang Rao,Qinglin Sheng,Jianbin Zheng
Herein, we report a simple and attractive self-assembly strategy for preparing graphene oxide–multiwalled carbon nanotube–(1-pyrenemethylamine)–gold (GO–MWCNT–PMA–Au) nanocomposites using 1-pyrenemethylamine (PMA) as a coupling agent. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). Further, a non-enzymatic nitrite sensor was fabricated by immobilizing GO–MWCNT–PMA–Au nanocomposites on a glassy carbon electrode (GCE). To obtain the optimal electrochemical experimental conditions, the effects of pH value and the volume of the as-prepared Au nanoparticle suspension were carefully investigated. Its electrochemical sensing properties were studied by cyclic voltammetry and differential pulse voltammetry. The electrochemical investigation showed that the GO–MWCNT–PMA–Au nanocomposites exhibited good catalytic performance for the oxidation of nitrite. The nitrite electrochemical sensor presented a wide linear range from 2.0 × 10−6 to 1.0 × 10−2 mol L−1, a high sensitivity of 483.51 μA mM−1 cm−2 and a low detection limit of 0.67 μmol L−1 at a signal-to-noise ratio of 3 (S/N = 3). It also exhibited good anti-interference capability and stability. This paper provides a self-assembly strategy for preparing nanocomposites which are used to construct improved electrochemical sensors.
研究领域:
分析化学
·
纳米生物技术
·
电化学传感
·
环境监测
·
食品安全
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2012
·Vol. 47
·期 11
·3277-3282
·
IF 2.105
Jing Bo Zhang,Xiao Ning Li,Shou Li Bai,Rui Xian Luo,Ai Fan Chen,Yuan Lin
Well-crystallized one-dimensional (1D) SnO 2 nanobelts were in situ prepared using a simple water-assisted chemical vapor deposition (CVD) method. The small Sn particles with Au-modifications were used as source materials instead of big size Sn grains to ensure the high yield of SnO 2 belts. The Au layer was modified on the small Sn particles by treating Sn powders in HAuCl 4 solution combined with the UV irradiation. The as-prepared SnO 2 nanobelts were characterized by SEM, HRTEM, XRD, EDS and XPS. These results indicate that the growth temperature plays an important role in controlling the length-to-width ratio of nanobelts. The length-to-width ratio decreases with the growth temperature from 850 °C to 1000 °C. The nanobelts prepared at 850 °C shows a single-crystalline tetragonal rutile phase with a high length-to-width ratio (approximately tens of microns in length and 40–70 nm in width). However, below 850 °C, nanobelts cannot be formed. The as-prepared nanobelts exhibited excellent sensing properties compared with SnO 2 nanoparticles and high sensing selectivity towards NO 2 . The high sensing selectivity to NO 2 is attributed to the oxygen vacancies presenting in the as-prepared nanobelts.
研究领域:
材料科学
·
纳米技术
·
传感器学
·
无机化学
·
半导体材料
✓ 已验证
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
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Zhenzhen Yang,Renliang Huang,Wei Qi,Liping Tong,Rongxin Su,Zhimin He
Reduced graphene oxide functionalized with magnetic Fe 3 O 4 nanoparticles and –PhSO 3 H groups (Fe 3 O 4 -RGO-SO 3 H) was reported for environmentally benign hydrolysis of cellulosic materials, which is an important process in integrated utilization of biomass resource. Except for –PhSO 3 H groups, –COOH and –OH groups derived from graphene oxide (GO) were also expected in the structure of Fe 3 O 4 -RGO-SO 3 H. Fe 3 O 4 -RGO-SO 3 H exhibited outstanding catalytic performance for the hydrolysis of cellulosic materials, due to its crumpling feature with clear layers and the coexistence of –COOH and –OH groups. The unique structure of Fe 3 O 4 -RGO-SO 3 H favors the accessibility of cellulose to the active sites of the material and facilitates the diffusion of the product molecules. –COOH groups on the surface of the material provide a large concentration of acidic functionality for hydrolyzing cellulose, while –OH groups readily adsorb cellulose through forming strong hydrogen bonds between –OH groups and the oxygen atoms in β-1,4 glycosidic bonds. Furthermore, Fe 3 O 4 -RGO-SO 3 H can also be easily separated from the reaction residue with an extra magnetic force and further used at least five times.
研究领域:
材料化学
·
催化化学
·
生物质能源
·
绿色化学
·
纳米材料科学
✓ 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
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Fanli Meng,Yi Luo,Yali Zhou,Jinwen Zhang,Yanzhen Zheng,Guozhong Cao,Xia Tao
A plasmon-enhanced upconversion composite Y 2 O 3 :Er/Au@TiO 2 (SYE/A@T) with a three-dimensional starlike morphology is prepared and then mixed with submicron TiO 2 (200 nm) to form a multifunctional scattering layer in TiO 2 -based dye-sensitized solar cells (DSSCs). In such starlike micronsized upconverter, Au nanoparticle-assisted plasmon effect can intensify the upconversion emission of Y 2 O 3 :Er, and simultaneously TiO 2 coating can improve the charge transport within SYE/A@T. Therefore, the SYE/A@T shows extended light-absorbing range to near-infrared region and improved light-scattering ability, leading to an improved photovoltaic performance of DSSCs. With the optimum mixing ratio, a conversion efficiency of 8.62% is attained, which is a significant improvement of 27.6% compared with the cell without adding SYE/A@T. Our work provides a feasible strategy to prepare an upconversion composite with plasmon-enhanced emission and enable this composite to accommodate the DSSCs system and improve the conversion efficiency of DSSCs.
研究领域:
材料科学
·
光伏技术
·
纳米光学
·
能源材料
·
表面等离激元
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 141
·期 10
·e55068
·
IF 3
Zhu Mian,Wang Bin,Lv Chao,Yu Zhenhui,Jingxian Liu
Gas separation membranes offer a cost-effective solution for capturing greenhouse gases, mitigating the global greenhouse effect. Ionic liquids (ILs) have emerged as one of the promising materials for greenhouse gas separation due to their strong affinity for CO 2 . In this study, we propose a laboratory-scale method for preparing IL–PVDF blend membranes with high CO 2 /N 2 selectivity. The separation performance of the membranes was evaluated using a custom gas permeation measurement system. The effects of casting solution composition, solidification method, and film-forming processes on separation performance were experimental investigated, and the obtained experimental data were used to train a back propagation neural network (BPNN) optimized by the Gray Wolf Optimizer (GWO) algorithm. This hybrid GWO–BPNN model was utilized to predict separation membrane efficiency, optimize the film-forming process, and identify the optimal range of process parameters. Notably, the GWO–BPNN model demonstrated a 2.76% higher prediction accuracy compared to a standalone BPNN. The results indicated that the GWO–BPNN algorithm has a great potential to accurately predict membrane separation efficiency and apply in optimal membrane process design (OMPD), and this method can significantly reduce the number of experimental trials required to achieve OMPD.
研究领域:
材料科学
·
化学工程
·
环境科学
·
膜分离技术
·
计算材料学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）