JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2017
·Vol. 129
·期 3
·1875-1885
·
IF 1.953
Cheng Jian,Zheng Yu,Li Zhenming,Liu Zuliang,Li Lixia,Zhao Fengqi,Xu Siyu
Abstract The purpose of this work was to study the catalytic reaction and its mechanism of ammonium perchlorate (AP) with cobalt complex of 2,6-diamino-3,5-dinitropyrazine-1-oxide (Co-LLM-105) during thermal decomposition process. At first, the catalytic performance of Co-LLM-105 on the thermal decomposition of AP was investigated by TG–DSC, TG-FTIR, non-isothermal kinetic and α – T kinetic curves analyses. Secondly, the thermal decomposition mechanism of Co-LLM-105 in the absence and presence of AP was proposed based on TG, DTG, DSC and thermolysis/RSFTIR analyses. The results showed that Co-LLM-105 exhibited excellent catalytic activity on the thermal decomposition of AP. Meanwhile, AP also exhibited some catalytic effects on the thermal decomposition of Co-LLM-105. Both of the components had catalytic effects on each other during the process. The formation of active CoCO 3 , Co 3 O 4 , CoO and Co(NH 3 ) 6 (ClO 4 ) 2 in situ in the system accounted for the higher catalytic activity of Co-LLM-105 for the thermal decomposition of AP was deduced. Graphical Abstract Co-LLM-105 exhibited excellent catalytic activity on the thermal decomposition of AP. Meanwhile, AP also exhibited some catalytic effects on the thermal decomposition of Co-LLM-105. Both of the components had catalytic effects on each other during the process.
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JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 1
·504-518
·
IF 2.302
Wan Qing,Liu Meiying,Xie Yili,Tian Jianwen,Huang Qiang,Deng Fengjie,Mao Liucheng,Zhang Qingsong,Zhang Xiaoyong,Wei Yen
Graphene oxide (GO)-based polymer nanocomposites were fabricated in aqueous solution via a novel strategy combination of mussel-inspired chemistry and Michael addition reaction. These GO-based polymer nanocomposites were used as efficient absorbents for the removal of organic dyes methylene blue (MB) from the aqueous solution. The successful preparation of GO-based polymer nanocomposites (GO-PDA-PSPSH) was confirmed by a number of characterization techniques in detail. Furthermore, a series of influential factors such as contact time, initial solution pH, and temperature were investigated and optimized. The optimal adsorption time of GO-PDA-PSPSH nanocomposites toward MB was 58 min. The maximum adsorption efficiency was occurred at pH 7. On the other hand, accompanying with the elevation of temperature, removal efficiency of GO-PDA-PSPSH nanocomposites was significantly increased, indicating that the adsorption process of MB by GO-PDA-PSPSH nanocomposites was endothermic. More importantly, the adsorption capability of GO-PDA-PSPSH nanocomposites was obviously greater than many other GO-based nanocomposites. Taken together, we have developed a facile biomimetic strategy for the preparation of GO-based polymer nanocomposites, which showed excellent adsorption capability toward MB and are promising for environmental adsorption applications.
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ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY
·
2016
·Vol. 23
·期 1
·13-18
·
IF 1.87
Wang Weiwei,Ren Xingbi,Yu Mingming,Xia Lidong,Liu Ning,Peng Shuming
By a solution impregnation method, three modified stationary phases were prepared by contacting activated alumina with MnCl 2 at different MnCl 2 :Al 2 O 3 molar ratios = 1:10, 1:5, 1:2.5, respectively. N 2 sorption isotherms at 78 K were examined for the unmodified and modified samples, from which pore size distributions (PSD) of textural properties were derived with density function theory. Elution chromatographic tests of hydrogen isotopes were carried out at 78 K. The results indicated that both the microporous specific surface area (SSA) and the mesoporous SSA decline after modification, while the microporous SSA remains nearly unvaried among the modified ones. The chromatographic retention times as well as the bandwidths decline as the Mn content rises. The resolution of chromatographic peaks increases after modification, it remains unvaried and then decreases as the Mn content increases. The PSD of alumina SSA changed by the modification significantly influences the hydrogen isotopic elution chromatography.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 22
·23081-23091
·
IF 2.76
Mao Qianhui,Ji Feng,Wang Wei,Wang Qiquan,Hu Zhenhu,Yuan Shoujun
The reactivity and fate of parabens during chlorination were investigated in this work. Chlorination kinetics of methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) were studied in the pH range of 4.0 to 11.0 at 25 ± 1 °C. Apparent rate constants ( k
app ) of 9.65 × 10 −3 M -0.614 ·s −1 , 1.77 × 10 −2 M -1.019 ·s −1 , 2.98 × 10 −2 M -0.851 ·s −1 , and 1.76 × 10 −2 M -0.860 ·s −1 for MeP, EtP, PrP, and BuP, respectively, were obtained at pH 7.0. The rate constants depended on the solution pH, temperature, and NH 4
+ concentration. The maximum k
app was obtained at pH 8.0, and the minimum value was obtained at pH 11.0. The reaction rate constants increased with increasing temperature. When NH 4
+ was added to the solution, the reaction of parabens was inhibited due to the rapid formation of chloramines. Two main transformation products, 3-chloro-parabens and 3,5-dichloro-parabens, were identified by GC-MS and LCMS-IT-TOF, and a reaction pathway was proposed. Dichlorinated parabens accumulated in solution, which is a threat to human health and the aqueous environment.
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Journal of Coatings Technology and Research
·
2016
·Vol. 13
·期 6
·1115-1121
·
IF 1.342
Liang Tao,Li Hongqiang,Lai Xuejun,Su Xiaojing,Zhang Lin,Zeng Xingrong
The super-hydrophilic polymer coating film can easily be be peeled off from a substrate with the existence of water, which is a fatal drawback in practical applications. Herein, a facile approach is proposed to prepare UV-curable super-hydrophilic polyacrylate coating film that is chemically grafted on the surface of γ -methacryloxypropyltrimethoxysilane-modified glass substrate. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that the polyacrylate coating films were successfully grafted onto the glass substrate and exhibited rough micro-groove structure. The obtained polyacrylate coating film possessed super-hydrophilicity with the water contact angle close to nearly zero as well as good transmittance and antifogging property.
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JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2016
·Vol. 46
·期 12
·1177-1186
·
IF 2.223
Guo Jie,Hou Yongjiang,Li Bo,Wang Yaquan
Abstract The Ni–B-modified carbon paste electrodes were synthesized by the electroless deposition, followed by thermal treatment. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were performed to gather information about the morphology, crystallinity, and binding energy. The fabricated Ni–B/C electrodes are applied to methanol electrooxidation in alkaline media. The results show that Ni–B/C catalyst with a comparable amount of microcrystalline Ni and Ni 3 B, 59 and 41 wt%, displayed a significantly enhanced electrocatalytic activity, which is approximately three times the activity of the unheated Ni–B/C catalyst. The synergetic mechanism of methanol oxidation was proposed that involves one Ni 3 B site favor the adsorption and activation of the methanol molecule and one Ni site for oxidative mediation of methanol. In addition, the kinetic parameters of the reaction were calculated using linear sweep voltammetry. Graphical abstract The illustration of the speculated methanol oxidation mechanism.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 28
·期 1
·958-962
·
IF 1.798
Wang Han,Li Haiying,Li Shouchun,Liu Li,Wang Lianyuan,Guo Xuexin
Biomorphic In 2 O 3 –ZnO hollow microtubules were synthesized by using cotton as template and followed by calcination. This environmental-friendly method using biomaterials as templates can be used to synthesize metal oxide semiconductor materials with specific morphologies. The structural and microscopy characterization were carried out with X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy. The SEM images display the porous structure of the as-obtained hollow microtubules, which is beneficial to increase gas sensing properties of materials. Gas sensors based on In 2 O 3 -doped ZnO hollow microtubules were investigated and the test results demonstrate the excellent acetone sensing properties of such porous materials. The response of In 2 O 3 –ZnO hollow microtubule sensors to 100 ppm acetone at the optimum temperature of 300 °C is 62.5, meanwhile the response and recovery times are 3 and 7 s, respectively. Moreover, even at 0.1 ppm of acetone detectable response can be observed, and the value is 2.82. At the same time the sensors have selectivity to acetone.
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FIBERS AND POLYMERS
·
2016
·Vol. 17
·期 8
·1123-1130
·
IF 1.022
Guo Mulin,Zhang Chao,Xu Jianjian,Luo Zhengwei,Wei Wuji
An efficient, simple and facile process, i.e., suspension grafting polymerization combined with melt-blown technique, was employed to synthesize Polypropylene-g-(acrylic acid-co-acrylamide) nonwoven fabrics [PP-g-(AA-co-AM) nonwovens]. In this study, the grafting mechanism and the effect of synthesis parameters on grafting percentage (GP) were investigated. The as-synthesized products were characterized by melt flow rate (MFR), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), water contact angle (WCA) and thermalgravimetric analysis (TGA). Besides, the uptake properties of metal ions (i.e., Ba 2+ , Cu 2+ , Ni 2+ , Mg 2+ , Al3+, Ca 2+ ) on the PP-g-(AA-co-AM) nonwovens in dynamic condition were studied. Results of FTIR showed that AA and AM were successfully grafted onto the PP surface. The decrease in WCAs of the grafted nonwovens with the increasing GP indicated that (AA-co-AM) side chains existed as the hydrophilic component. TGA results revealed that no significant change in thermal stability was found in grafted PP samples. The synthesis experiments showed that the highest GP was obtained at grafting time 3 h, water 3 ml/g, xylene 15 wt%, benzoyl peroxide 0.5 wt%, AA, AM 30 wt% and AA: AM 1:1, with a GP of 16.7 %, and a grafting efficiency of 67 %. However, MFR measurement and SEM image demonstrated that PP-g-(AA-co-AM) nonwovens with the highest GP showed almost no mechanical strength existed between filaments resulting in the occurrence of deformation and contraction of nonwovens, and breaking up into small pieces. Comprehensively, the optimal GP was 8.7 %, and the corresponding PP-g-(AA-co-AM) nonwovens exhibited higher metal ions uptake capacity than pristine PP nonwovens in the dynamic adsorption process.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 12
·4705-4712
·
IF 4.58
Chen Lihua,Lv Shuli,Gao Zhigang,Chen Chuangfu
The authors describe a voltammetric immunoassay for the carcinoembryonic antigen (CEA). A GCE was modified by electrodeposition of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with tannic acid (TA). Subsequently, four-armed poly(ethylene glycol) (PEG) was assembled onto the modified surface through hydrogen bonding. The fabrication steps were characterized by scanning electron microscopy, energy dispersive spectroscopy, fourier transform infrared spectroscopy, contact angle measurements, electrochemical impedance spectroscopy and differential pulse voltammetry. The PEG/TA-PEDOT surface is shown be super-hydrophilic and to possess anti-fouling capability. Antibody against CEA was then covalently immobilized on the electrode. By using hexacyanoferrate as an electrochemical probe and at a working potential of 0.18 V vs SCE, the amperometric response is linear in the 10 ag·mL −1 to 1.0 ng·mL −1 CEA concentration range, and the detection limit is as low as 4.8 ag·mL −1 (at an S/N ratio of 3). The assay was applied to the quantification of CEA in 1:10 diluted human serum samples. Recoveries ranged from 103.7 to 108.7%, and relative standard deviations from 2.9 to 4.8%.
Schematic of an electrochemical immunosensor for the carcinoembryonic antigen (CEA). It is based on the use of tannic acid (TA) and poly(ethylene glycol) (PEG), both deposited on a glassy carbon electrode (GCE), and using hexacyanoferrate as the electrochemical probe. The sensor has a wide linear range and a 4.8 ag·mL −1 detection limit.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
He Shichong,Zhu Lizhong
Sorptive landfill liners can prevent the migration of the leachate pollutants. However, their sorption ability will decrease over time. A method should be developed to maintain the sorption ability of landfill liners. In this study, we combined cetyltrimethylammonium bromide-bentonite (CTMAB-bentonite) and zero-valent iron (ZVI) to develop a self-cleaning liner that can retain its sorption ability for a long period. Batch experiments and calculation simulations were employed to analyse the sorption ability of this liner material and the ecological risk of halogenated hydrocarbons. The results showed that CTMAB-bentonite could sorb halogenated hydrocarbons well, with saturated sorption capacities ( Q
m ) of 10.2, 14.5, 6.69, 18.5, 29.4, and 49.7 mg·g -1 for dichloroethane (DCA), trichloroethane (TCA), dichloroethene (DCE), trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,3- dichloropropene (1,3-DCP), respectively. Using the mixture of 0.5 g iron and 0.5 g CTMAB-bentonite could dramatically increase the removal efficiency of DCE, TCE, and PCE. The reaction with ZVI did not change the structure of CTMAB-bentonite and its sorption ability remained consistent. Calculation results suggested that the self-cleaning landfill liner would dramatically decrease the hazard index (HI) of the eluate. However, the humic acid and salt in leachate would cause a reduction in the removal of halogenated hydrocarbons.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Zhang Zhan,Wang Di,Qiao Shanlei,Wu Xinyue,Cao Shuyuan,Wang Li,Su Xiaojian,Li Lei
Hepatocellular carcinoma (HCC) treatment remains lack of effective chemopreventive agents, therefore it is very attractive and urgent to discover novel anti-HCC drugs. In the present study, the effects of chlorogenic acid (ChA) and caffeic acid (CaA) on HCC induced by diethylnitrosamine (DEN) were evaluated. ChA or CaA could reduce the histopathological changes and liver injury markers, such as alanine transarninase, aspartate aminotransferase, alkaline phosphatase, total bile acid, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol. The underlying mechanisms were investigated by a data integration strategy based on correlation analyses of metabonomics data and 16 S rRNA gene sequencing data. ChA or CaA could inhibit the increase of Rumincoccaceae UCG-004 and reduction of Lachnospiraceae incertae sedis , and Prevotella 9 in HCC rats. The principal component analysis and partial least squares discriminant analysis were applied to reveal the metabolic differences among these groups. 28 different metabolites showed a trend to return to normal in both CaA and ChA treatment. Among them, Bilirubin, L-Tyrosine, L-Methionine and Ethanolamine were correlated increased Rumincoccaceae UCG-004 and decreased of Lachnospiraceae incertae sedis and Prevotella 9 . These correlations could be identified as metabolic and microbial signatures of HCC onset and potential therapeutic targets.
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IRANIAN POLYMER JOURNAL
·
2017
·Vol. 26
·期 7
·531-539
·
IF 1.422
Sun Yujun,Jiang Xiancai,Hou Linxi
Quaternized poly(vinyl alcohol)/chitosan (QPVA/CS) composite membranes were prepared by solution casting method with AlCl 3 ·6H 2 O aqueous solution as solvent for CS and glutaraldehyde as a crosslinker. The crystalline, thermal and mechanical properties of the QPVA/CS composite membranes were studied by Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry, thermogravimetry and tensile test measurements, respectively. The composite membranes were immersed in potassium hydroxide aqueous solution to form polymer electrolyte membranes. The alkaline uptake, swelling ratio, ion conductivity and methanol permeability of the electrolyte membranes were studied. The experimental results indicated that aluminum chloride hexahydrate (AlCl 3 ·6H 2 O) had a positive effect on the mechanical properties of the QPVA/CS composite membrane. The elongation-at-break of this membrane reached the maximum of 401.0%. The alkaline uptake and swelling ratio of the composite membranes decreased. With the addition of 30 wt% AlCl 3 ·6H 2 O, the composite membrane showed the ion conductivity and methanol permeability of 1.82 × 10 −2 S cm −1 and 2.17 × 10 −6 cm 2 s −1 , respectively. These values were higher than those of the membrane with acetic acid as the solvent for CS. The selectivity of the QPVA/CS membrane could reach 8.39 × 10 3 S s cm −3 . This study showed that with AlCl 3 ·6H 2 O as the solution for CS, the high performance QPVA/CS composite alkaline polymer electrolyte membrane could be prepared.
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