JOURNAL OF CHEMICAL THERMODYNAMICS
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2013
·
IF 2.297
Chaoyuan Wang,Yonghong Hu,Wenge Yang,Kai Wang,Yihua Li,Song Guo
The solubility of 2,3,4,5-tetrabromothiophene in (ethanol + tetrahydrofuran) binary solvent mixtures was measured within the temperature range from (278.15 to 322.15) K. The solubility increases with the rise of temperature, while it decreases with increasing ethanol content at constant temperature. The experimental data were fitted using the two variants of the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) equation and the Jouyban–Acree equation, respectively. All the three equations were proven to give good representations of the experimental values. Computational results showed that the variant two of CNIBS/R–K equation was superior to the other two equations. The thermodynamic properties of the solution process, including the Gibbs free energy, enthalpy, and entropy, were calculated by the van’t Hoff analysis. The values of both the enthalpy change and the standard molar Gibbs free energy change of solution were positive, which indicated that the process was endothermic.
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JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 11
·1-7
·
IF 1.92
Gao Lijun,Luo Yucheng,Lin Yongjia,Su Ting,Su Riping,Feng Jiuying
In order to improve the catalytic efficiency of zinc glutarate (ZnGA) used in the CO 2 /propylene oxide (PO) copolymerization, silica-supported zinc glutarate catalysts (ZnGA/SiO 2 ) are prepared via a rheological phase reaction with a little toluene as a reaction medium. Wide-angle X-ray diffraction (WAXD) tests of the catalysts illustrate that the crystal quality increases and the overall crystallinity declines after supporting. The scanning electron microscope (SEM) images show that the proportion of supported ZnGA increases with increasing the SiO 2 proportion. Accordingly, the polymer yields increase from 12.7 Kg polymer/mol Zn of ZnGA to 25.6 of ZnGA/SiO 2 . And the almost alternating poly(propylene carbonasstes) (PPCs) with the carbonate content of above 97 % and the M
n s of above 10, 000 g/mol are obtained. This work illustrates that the catalytic efficiency does not increase sharply like the supported catalysts used in olefin polymerization because of the decline in overall crystallinity of ZnGA. The catalytic efficiency is expected to be enhanced significantly if it can be improved for ZnGA/SiO 2 .
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SOLAR ENERGY
·
2017
·
IF 4.018
Zhaoli Zhang,Yanping Yuan,Sami Alelyani,Xiaoling Cao,Patrick E. Phelan
Ternary carbonates in the form of Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 enforced by expanded graphite, graphene nanosheets and multi-walled carbon nanotubes are originally prepared though the solution-evaporation with the purpose of enhancing heat transfer for employment in concentrating solar power. FT-IR, XRD and SEM results indicate that three carbon materials are physically dispersed into composite carbonates with the effect of supporting structural support as well as improved thermal properties. The presence of carbon materials presents a slight effect on the melting and freezing temperature of ternary carbonates. It is apparent that enhancement of carbon materials on the heat transfer of the composite carbonates is mainly manifested in the aspect of thermal conductivity improvement. Expanded graphite, graphene nanosheets and multi-walled carbon nanotubes show respectively the enhancement of approximately 59.1%, 32.9% and 24.8% on average to thermal conductivity. Carbon materials also illustrate obvious improvement on the specific heat and the strengthening effect of liquid composite carbonates is generally better than that of solid carbonates. Average specific heat of composite carbonates modified by expanded graphene, graphene nanosheets and multi-walled carbon nanotubes is 1.278, 1.322 and 1.299 J/(g·°C) for solid and 1.502, 1.638, and 1.533 J/(g·°C) for liquid, respectively. Additionally, prepared composite carbonates exhibit superior cyclic stability and it is concluded that composite carbonates with carbon materials as effective latent heat storage materials will have great potential for application in thermal energy storage in terms of satisfactory thermal properties.
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2016
·Vol. 310
·期 2
·671-678
·
IF 0.983
Li Shicheng,Wang Xiaoli,Huang Zhaoya,Du Liang,Zhang Dong,Tan Zhaoyi,Fu Yibei,Wang Xiaolin
In this study, we examined the sorption and desorption behavior of U(VI) on/from a Chinese bentonite in the solid–liquid system using batch experiments, and the influence of pH, ionic strength and humic acid (HA) on the sorption–desorption hysteresis in the solid–liquid system were quantitatively calculated. It was revealed that the hysteresis was enhanced with increasing pH and increasing ionic strength. HA promoted the sorption, but lower the sorption–desorption hysteresis. Meanwhile, hysteresis in ternary bentonite-HA-U system was found to be higher than that in bentonite-U-HA system, indicating different sorption structures formed because of different addition sequence.
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APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Qiang Wang,Lei Yang,Bing Dai,Jie Bai,Zhenhuai Yang,Shuai Guo,Yurong He,Jiecai Han,Jiaqi Zhu
Forests of vertically aligned carbonaceous microcones are fabricated directly on a nickel mesh by microwave-plasma-assisted chemical vapor deposition. The microstructure is formed through a simple one-step process involving self-assembly. The fabricated composite exhibits superhydrophobicity and superoleophilicity as well as low density, owing to which it floats on water and can be used for the in-situ separation of oil from water at the oil/water interface. Furthermore, the composite exhibits pH responsivity, and its water permeability can be varied simply by altering the pH of the aqueous solution. In addition, the composite is suitable for use as an electrode material for supercapacitors owing to its large geometric surface area, porous structure, and superior electrical properties, which allow for fast ion and electron transportation. Thus, this composite consisting of forests of vertically aligned carbonaceous microcones on a nickel mesh is expected to find use in a wide range of fields and applications, including in environmental cleanup, flow switches, and energy storage devices.
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Food Analytical Methods
·
2017
·Vol. 10
·期 10
·3415-3423
·
IF 2.038
Sha Min,Zhang Zhengyong,Gui Dongdong,Wang Yanbo,Fu Linglin,Wang Haiyan
A fingerprinting approach was developed by means of high-performance ion mobility spectrometry with direct electrospray ionization (ESI-HPIMS) for the quality consistency and authentication of apple essence which contain many analytes. Thirty-four apple essence samples of the same brand and commercialized as a same product but brewed in four different manufacturers were used to establish the fingerprints. Hierarchical clustering analysis (HCA) was performed to evaluate the similarity and variation of these samples. A combined data matrix was constructed with the use of individual data matrix of ion mobility spectrum in positive and negative ion modes. For comparison, ion mobility spectrum fingerprints in positive and negative ion modes respectively were also applied to the quality assessment of the same samples. Finally, our study demonstrated that the fusion of fingerprints did indeed provide more information and could be used to comprehensively conduct the quality consistency evaluation and discrimination of apple essences from similar products. It is suggested that this fingerprint approach is suitable for analysis of other complex, multianalyte substances.
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JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 10
·4856-4863
·
IF 2.302
Han Sheng,Wang Chi,Huang Yanshan,Jiang Jianzhong,Huang Yinjuan,Xu Zhixiao,Wu Dongqing
Three-dimensional hybrids of cobalt oxide (Co 3 O 4 ) and graphene frameworks are fabricated via a facile hydrothermal self-assembly process. By adjusting the time of the hydrothermal treatment, the morphologies of the Co 3 O 4 components can be modified from rods to nanoparticles, which further manifest influences on the electrochemical performance of the hybrids. As the anode in lithium-ion battery, the hybrid loaded with spherical Co 3 O 4 nanoparticles exhibits the highest reversible capacity of 1148 mA h g −1 at 100 mA g −1 for 100 cycles among the three samples. Even at a high current density of 5000 mA g −1 , its reversible capacity is still kept at 600 mA h g −1 , outperforming the reported hybrids of Co 3 O 4 and graphene.
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ENERGY & FUELS
·
2017
·
IF 3.091
Guolin Jing,Zhengnan Sun,Ziyi Tu,Xudong Bian,Yu Liang
Nanohybrid pour-point depressants (PPDs) were prepared by organically modified nano-SiO2 in copolymers of ethylene and vinyl acetate (EVA) with various vinyl acetate contents. The effects of nanohybrid PPDs on the cold-flow properties of 25 wt % wax model oil were evaluated. The crystallization behavior and crystal morphology of the model oil at low temperatures were also observed using polarized optical microscopy. The results indicated that the co-crystallization and dispersion effects of EVA on wax crystals are the key factors in determining the heterogeneous nucleation effect of the nanohybrid PPDs. The vinyl acetate content in EVA strongly affects the compatibility between the modified nanosilica and EVA. As a result, the selection of an appropriate EVA according to the oils used and the compatibility factor is important. In this work, EVA (VA = 32%)/modified nano-SiO2 composite PPD [N-SiPPD(32)] provided the best cold-flow improvement for the model oil when doped at 500 ppm. The pour point of the model oil was reduced from 34 to 5 °C, which resulted in a regular, diamond-shaped, and uniform arrangement of wax morphologies.
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RSC Advances
·
2017
·Vol. 7
·期 17
·10564-10569
·
IF 3.108
Xiaowen Zhang,Yang Li,Zhongliang Hu,Zhi Chen,Jianrong Qiu
The second near-infrared window (NIR-II, 1000–1400 nm) is ideal for fluorescence imaging owing to negligible tissue scattering and minimal autofluorescence. NIR-II luminescence nanophosphors are promising materials for fluorescence imaging. Mn5+ is emerging as a new luminescent indicator owing to its typical NIR-I (800 nm) to NIR-II (1190 nm) downconversion luminescence. Herein, we report a facile synthesis approach to prepare Mn5+ doped Ba3(MO4)2 (M = V, P) nanoparticles with a remarkably sharp emission peak around 1190 nm in the NIR-II region for the first time to our knowledge. The developed two-step approach based on efficient anion exchange reaction is able to not only stabilize the valence but also keep the controlled morphology and uniform size. It is highly possible that the general approach will provide a new perspective on synthesizing special valence ion doped nanosized materials.
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RSC Advances
·
2017
·Vol. 7
·期 50
·31173-31179
·
IF 3.108
Chao Pang,Ruiqiang Yang,Amit Singh,Hanjiao Chen,Michael K. Bowman,Ningzhong Bao,Liming Shen,Arunava Gupta
Anisotropic-shaped CuCr2Se4 nanocrystals have been synthesized by thermal decomposition and reaction of novel mixed metal–oleate complexes with selenium in a high-boiling point organic solvent, trioctylamine (TOA). The synthesized CuCr2Se4 nanocrystals exhibit close to triangular and hexagonal morphology, with an average size of 20 nm. X-ray diffraction patterns and XPS spectral analysis confirm the formation of the pure spinel phase without any impurities. A possible reaction mechanism is suggested and formation pathways for the triangular and hexagonal shaped CuCr2Se4 nanocrystals are proposed. Magnetic studies indicate that the anisotropic-shaped CuCr2Se4 nanocrystals are superparamagnetic near room temperature but exhibit ferromagnetic behavior at lower temperatures, with magnetization values of 31 and 43 emu g−1 at 300 and 5 K, respectively.
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REVIEW OF SCIENTIFIC INSTRUMENTS
·
2017
·Vol. 88
·期 11
·
IF 1.515
Li Chuanjun,Cao Yang,Guo Rui,He Shengya,Xuan Weidong,Li Xi,Zhong Yunbo,Ren Zhongming
The contact angle (CA) goniometer adaptable to a superconducting magnet was developed based on the sessile drop method. The goniometer mainly consisted of the sampling system, the supporting system, and the image acquisition system. Some improvements were taken to avoid the effects of the magnetic field (MF) on the CA measurement. As an example, the CAs of water on two substrates of silica and polymethyl methacrylate (PMMA) were measured using the goniometer. The results with and without a MF showed a good repeatability and reliability. Additionally, the MF was found to reduce the CA of water, which probably stemmed from the change of the surface tension in the MF. The CA goniometer will become an important tool which is used to study the wettability of liquids on a solid in the MF.
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PubMed
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2017
·
IF 2.499
Mohammad Russel,Sun Zhenxiang,Liu Changrui,Zhou Hao,Liu Lifen,Sophocleous Marios,Zhou Yong
A microwave-based, rapid and non-destructive spectroscopic technique has been developed to monitor contamination in beach-sand. A set of in-vitro experiments were designed to test beach-sand samples contaminated with meta-cresol (m-cresol) and water with weight/weight percentages of 0–20%, using a prototype probe with a long sample holder (16 mm). The frequency range used was 10 MHz–1 GHz during the whole experiment. Air and Teflon were investigated as low-loss materials, whilst ethanol was used as a typical, frequency-dependent, polar material to further verify the technique. The real part of the relative complex permittivity was found to be very close to the theoretical and fitting very well with the Debye model. This dielectric technique showed a linear relationship between the real part of relative complex permittivity and m-cresol/water content, for a frequency range of 0.02–0.7 GHz for water and 0.02–0.2 GHz for m-cresol. The sensitivity was calculated to be 0.58% −1 and 0.12% −1 for water and m-cresol, respectively.
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