IONICS
·
2014
·Vol. 21
·期 4
·917-925
·
IF 1.836
Zheng Tao,Xing Qian,Ren Shitong,Zhang Liaoyun,Li Huayi
Hyperbranched poly(glycidol) containing hydroxyl groups was firstly synthesized via anionic polymerization and then reacted with 2-bromoisobutyl bromide to form macroinitiator HPG-Br. Finally, a hyperbranched star polymer (HPG-PPEGMA) was successfully prepared by atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate using HPG-Br as macroinitiator. The structures and properties of the obtained polymers were characterized by 1 H NMR, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The ionic conductivity of the polymer electrolytes composed of HPG-PPEGMA and lithium bis(trifluoromethanesulfonimide) (LiTFSI) was investigated via electrochemical impedance spectroscopy. The results showed that the room temperature ionic conductivity of the prepared hyperbranched star polymer electrolytes had a higher ionic conductivity. When [EO]/[Li] was 20, the ionic conductivity of the hyperbranched star polymer electrolyte was up to 1 × 10 −4 Scm −1 at 30 °C. The onset decomposition temperature of the hyperbranched star polyether could reach 374 °C, indicating that the hyperbranched star polymer had a good thermal stability. The XRD results showed that the structure of the hyperbranched star polymer was beneficial to improve the ionic conductivity due to possessing a low degree of crystallinity.
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高影响因子
CATALYSIS LETTERS
·
2014
·Vol. 144
·期 6
·1001-1008
·
IF 2.291
Lin Chao,Tao Kai,Hua Dayin,Ma Zhen,Zhou Shenghu
Abstract Bimetallic Au 3 M (M = Ni, Co, Fe) nanoparticles (NPs) were synthesized by reducing a mixture of Au 3+ and metal cations (Ni 2+ , Co 2+ , Fe 3+ ) by butyllithium in the presence of oleylamine. Au 3 M NPs were then deposited onto a commercial SiO 2 support. The Au 3 M/SiO 2 samples were not particularly active in the catalytic reduction of p -nitrophenol unless they were converted into Au–MO
x
/SiO 2 after appropriate thermal treatment in air. The Au–MO
x
/SiO 2 catalysts showed good thermal stability and significantly higher p -nitrophenol conversions than Au/SiO 2 . Relevant characterization was conducted employing X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet–visible spectroscopy. Graphical Abstract
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高影响因子
Journal of Coatings Technology and Research
·
2014
·Vol. 11
·期 4
·517-531
·
IF 1.28
Li Xingjian,Hu Jing,Sun Daoxing,Zhang Yiheng
In the work, click chemistry coupling reaction was used to modify waterborne polyurethane (WPU) with a silane coupling agent, and then the as-prepared waterborne siloxane-polyurethane dispersion was incorporated into the nanosilica moieties forming the nanosilica reinforced waterborne siloxane-polyurethane (WSPUSi) nanocomposites. WSPUSi was characterized by FTIR, 1 H NMR, X-ray diffraction analysis, mechanical property testing, transmission electron microscopy, and thermogravimetric analysis. In order to highlight the excellent performance of WSPUSi, the traditional WPU/nanosilica composites (TWPUSi) were also fabricated. Comparative study on the water sorption, scanning electron microscopy, acetone and toluene absorption and UV–visible transmission spectroscopy of WSPUSi and TWPUSi with the varying nanosilica was conducted. The research results indicate that WSPUSi nanocomposites with reinforced mechanical properties and thermal stability showed excellent comprehensive performance containing water resistance and solvent resistance in comparison with TWPUSi.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 11
·7219-7226
·
IF 2.757
Xie Jinchuan,Lin Jianfeng,Zhou Xiaohua,Li Mei,Zhou Guoqing
Low-solubility contaminants with high affinity for colloid surfaces may form colloid-associated species. The mobile characteristics of this species are, however, ignored by the traditional sorption/distribution experiments in which colloidal species contributed to the immobile fraction of the contaminants retained on the solids as a result of centrifugation or ultrafiltration procedures. The mobility of the contaminants in subsurface environments might be underestimated accordingly. Our results show that colloidal species of 239 Pu in three-phase systems remained the highest percentages in comparison to both the dissolved species and the immobile species retained on the granite grains (solid phase), although the relative fraction of these three species depended on the colloid types. The real solid/liquid distribution coefficients ( K
s/d ) experimentally determined were generally smaller than the traditional K
s/d (i.e., the K
s+c/d in this study) by ~1,000 mL/g for the three-phase systems with the mineral colloids (granite particle, soil colloid, or kaolinite colloid). For the humic acid system, the traditional K
s/d was 140 mL/g, whereas the real K
s/d was approximately zero. The deviations from the real solid/liquid K
s/d were caused by the artificially increased immobile fraction of Pu. One has to be cautious in using K
s/d -based transport models to predict the fate and transport of Pu in the environment.
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PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2015
·Vol. 407
·期 30
·9177-9184
·
IF 3.436
Gao Lin,Han Wenjuan,Li Xiuying,Wang Jixiang,Yan Yongsheng,Li Chunxiang,Dai Jiangdong
A fluorescent core-shell molecularly imprinted polymer based on the surface of SiO 2 beads was synthesized and its application in the fluorescence detection of ultra-trace λ -cyhalothrin (LC) was investigated. The shell was prepared by copolymerization of acrylamide with allyl fluorescein in the presence of LC to form recognition sites. The experimental results showed that the thin fluorescent molecularly imprinted polymer (FMIP) film exhibited better selective recognition ability than fluorescent molecularly non-imprinted polymer (FNIP). A new nonlinear relationship between quenching rate and concentration was found in this work. In addition, the nonlinear relationship allowed a lower concentration range of 0–5.0 nM to be described by the Stern–Volmer equation with a correlation coefficient of 0.9929. The experiment results revealed that the SiO 2 @FMIP was satisfactory as a recognition element for determination of LC in soda water samples. Therefore this study demonstrated the potential of MIP for the recognition and detection of LC in food.
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PubMed
高影响因子
Journal of Central South University
·
2015
·Vol. 22
·期 3
·868-873
·
IF 0.52
Qin Wen-qing,Luo Hong-lin,Liu Wei,Zheng Yong-xing,Yang Kang,Han Jun-wei
The volatilization of stibnite (Sb 2 S 3 ) in nitrogen from 700 to 1000 °C was investigated by using thermogravimetric analysis. The results indicate that in inert atmosphere, stibnite can be volatilized most efficiently as Sb 2 S 3 (g) at a linear rate below 850 °C, with activation energy of 137.18 kJ/mol, and the reaction rate constant can be expressed as k =206901exp(−16.5/ T ). Stibnite can be decomposed into Sb and sulfur at temperature above 850 °C in a nitrogen atmosphere. However, in the presence of oxygen, stibnite is oxidized into Sb and SO 2 gas at high temperature. Otherwise, Sb is oxidized quickly into antimony oxides such as Sb 2 O 3 and SbO 2 , while Sb 2 O 3 can be volatilized efficiently at high temperature.
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 3
·1-15
·
IF 2.184
Liu Yingbo,Li Zhen,Yu Libo,Sun Shuqing
In this work, the influences of cationic precursors on the quality of photoelectrode, consequently on the performance of the quantum dot-sensitized solar cells (QDSCs) have been studied. CdS QDSCs have been prepared using successive ionic layer absorption and reaction (SILAR) method. Three cadmium precursors including nitrate (Cd(NO 3 ) 2 ), chloride (CdCl 2 ), and acetate (Cd(Ac) 2 ) were employed for the synthesis and absorption of CdS nanoparticles on nanostructure TiO 2 film. The loading amount and nanoparticle size of the CdS on mesoporous TiO 2 film showed a significant difference while using various cadmium precursors in the same SILAR cycles. Both the light-harvesting ability and the obtained incident photon-to-current conversion efficiency values show the trend of deposition rate caused by cadmium precursors. Further, it was proposed that an effective cationic precursor could provide a good connection between QD sensitizer and TiO 2 interface by electrochemical impedance spectroscopy analysis. Under AM 1.5 G full one sun illumination, the final power conversion efficiency of CdS QDSC based on Cd(Ac) 2 was 2.10 %, and PCE values of 1.57 and 1.20 % were obtained for solar cells sensitized by CdS QDs prepared by CdCl 2 and Cd(NO 3 ) 2 , respectively. The cationic precursor effect was further applied in PbS/CdS co-sensitized solar cells. The PbS/CdS QDSCs based on acetate cationic precursors provide a photocurrent of 19.24 mA/cm 2 and PCE of 3.23 % in comparison with 11.26 mA and 2.13 % obtained with nitrate acetate salts. Noticeably, the CdS and PbS/CdS QDSCs based on various cationic precursors prepared by SILAR exhibited good photocurrent stability under several light on–off cycles.
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高影响因子
WOOD SCIENCE AND TECHNOLOGY
·
2014
·Vol. 48
·期 6
·1241-1255
·
IF 1.873
Liu Wendi,Chen Tingting,Wen Xiaoyun,Qiu Renhui,Zhang Xincong
Bamboo fibers were mechanically extracted from raw green bamboos by crushing, rolling, and combing techniques with 1,4-butanediol as a solvent. The morphology of the bamboo fibers thus obtained was analyzed. The bamboo fibers were treated with isocyanatoethyl methacrylate (IEM) in the presence of dibutyltin dilaurate as a catalyst, to improve the interfacial adhesion between the fibers and unsaturated polyester (UPE) resins. The bamboo fibers reinforced UPE composites were prepared by hand lay-up compression molding. FTIR, XPS, and NMR analyses indicated that the IEM was covalently bonded onto the bamboo fibers via carbamate linkages. The IEM treatments significantly increased the tensile strength, flexural strength, flexural modulus, and water resistance of the resulting composites and yet decreased the impact strength of the composites. The SEM images of the tensile-fractured surfaces of the IEM-treated bamboo fibers–UPE composites revealed that the fiber treatments markedly improved the interfacial adhesion between the bamboo fibers and UPE resins.
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高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2014
·Vol. 44
·期 11
·1165-1170
·
IF 2.147
Pu Zonghua,Liu Qian,Asiri Abdullah M.,Sun Xuping
In this communication, we demonstrate the preparation of Ni nanoparticles-graphene hybrid film via simultaneous electrochemical reduction of graphene oxide and Ni 2+ on conductive substrate for the first time. We further show the utilization of such hybrid film as an efficient oxygen evolution reaction electrocatalyst with highly catalytic activity and good durability.
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高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2013
·Vol. 69
·期 1
·9-16
·
IF 1.66
Hu Qing,Chen Xiaofeng,Zhao Naru,Li Yuli,Mao Cong
This paper reports a facile method for fabricating monodispersed mesoporous bioactive glass sub-micron spheres (MBGS) using dodecylamine (DDA) as a catalyst and template agent in sol–gel process. The effects of synthesis conditions including the amount of DDA, temperature of hydrolysis and the volume ratio of alcohol to water (AW ratio) on the resulting particle size, morphology, monodispersity and pore size distribution of MBGS are investigated and discussed. The results indicate that the particle size, morphology, monodispersity and pore size distribution of MBGS depend on the amount of DDA, the temperature of hydrolysis and the AW ratio. Meanwhile, using DDA as the structure directing agent and hydrolysis catalyst under optimal synthesis conditions (e.g. 4 g DDA, hydrolysis temperature at 40 °C and AW ratio at 4) is in favor of obtaining MBGS with mesoporous surface structure, large specific surface area (362.073 m 2 g −1 ), relatively homogeneous particle size (~560 nm) as well as good apatite-forming activity. The unique structure and properties may turn MBGS into a good candidate as a drug delivery carrier or an injectable biomaterial for bone tissue regeneration.
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2014
·Vol. 41
·期 8
·5311-5321
·
IF 1.54
Huang Pingzhen,Gu Aijuan,Wang Jinxing
Efficient production of 5-hydroxymethylfurfural (HMF) through the dehydration of sugars was achieved by developing a new catalyst caprolactam hydrogen sulfate ([CPL]HSO 4 ) ionic liquid or using metal halide as the co-catalyst in a new water/proprylene glycol monomethyl ether solvent system. With an optimum synthesis condition, the yield of HMF derived from fructose dehydration at 105 °C for 90 min is as high as 80.5 % in the presence of [CPL]HSO 4 . The nature behind the attractive results was revealed by proposing the catalysis mechanism of the fructose dehydration. The yield of HMF is about 70 % using [CPL]HSO 4 as the catalyst for fructose dehydration after being reused five times. The catalyst system [CPL]HSO 4 /metal halide was used for the dehydration of sucrose, and the optimum yield is as high as 64–68 %.
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高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2014
·Vol. 300
·期 3
·1235-1244
·
IF 1.415
Yu Xiao-Feng,Liu Yun-Hai,Zhou Zhi-Wei,Xiong Guo-Xuan,Cao Xiao-Hong,Li Min,Zhang Zhi-Bin
The phosphorylated hydrothermal carbon spheres (HCS-PO 4 ) were developed by functionalizing hydrothermal carbon spheres (HCS) with o -phosphoethanolamine, and the structure and textural property were characterized by SEM and FT-IR. The parameters that affect the uranium(VI) sorption, such as solution pH, initial U(VI) concentration, contact time, and temperature, had been investigated. The HCS-PO 4 showed the highest uranium sorption capacity at initial pH 6.0 and contact time of 120 min. The adsorption kinetics was better described by the pseudo-second-order model, and the adsorption process could be well defined by the Langmuir isotherm and the maximum monolayer adsorption capacity increased from 80.00 to 434.78 mg/g after phosphorylation. The thermodynamic parameters, ∆ G° (298 K), ∆ H ° and ∆ S °, demonstrated shown that the sorption process of U(VI) onto HCS-PO 4 was feasible, spontaneous and endothermic in nature. The spent HCS-PO 4 could be effectively regenerated by 0.1 mol/L EDTA solution for the removal and recovery of U(VI) and reused for ten cycles at least. Selective adsorption studies showed that the HCS-PO 4 could selectively remove U(VI), and the selectivity coefficients of HCS in the presence of co-existing ions, Mg(II), Na(I), Zn(II), Mn(II),Co(II), Ni(II), Sr(II), Cs(I) and Hg(II) improved after functionalization.
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高影响因子
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