Journal of Chemistry
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2016
·
IF 0.996
Qing Han,Yunfei Liu,Dong Wang,Fulong Yuan,Xiaoyu Niu,Yujun Zhu
Selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) is of both fundamental and industrial interest. It is of great significance to evaluate the possible differences between different supports arising from metal dispersion and electronic effects, in terms of activity and selectivity. Herein, Pt catalysts on different carbon supports including carbon nanotubes (CNTs) and reduced graphene oxides (RGO) were developed by a simple wet impregnation method. The resultant catalysts were well characterized by XRD, Raman, N2 physisorption, TEM, and XPS analysis. Applied in the hydrogenation of cinnamaldehyde, 3.5 wt% Pt/CNT shows much higher selectivity towards cinnamyl alcohol (62%) than 3.5 wt% Pt/RGO@SiO2 (48%). The enhanced activity can be ascribed to the high graphitization degree of CNTs and high density of dispersed Pt electron cloud.
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Journal of the Iranian Chemical Society
·
2017
·Vol. 14
·期 10
·2087-2096
·
IF 1.407
Zhi Kangkang,Zhang Min,Yang Xin,Zhao Haitian,Dong Aijun,Zhang Hua,Wang Jing
In this paper, a kind of surface molecular imprinting polymers in hydrous solution, with glucose selectively recognition, was successfully synthesized by surface molecular imprinting method, using glucose (Glu) as template molecule, acrylamide as functional monomers, N,N ′-methylenebisacrylamide as the cross-linking agent, ammonium peroxydisulfate as the initiator, activated silica gel (SiO 2 @NH 2 ) as support particles. The influences of cross-linker, initiator as well as support particles amount on the adsorption capacity of Glu-MIPs were performed by single-factor experiments. The optimum conditions were 100 mg of cross-linker, 25 mg of initiator and 1 g of SiO 2 @NH 2 . The adsorption and thermodynamics research revealed that the adsorption of MIPs was fitted to Langmuir, maximum imprinting factor of 2.49 and maximum absorption capacity of 50.06 mg/g. Furthermore, a procedure of extraction of glucose from real fruits samples using the Glu-MIPs as solid-phase extraction adsorbent was developed to apply in analytical techniques.
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IRANIAN POLYMER JOURNAL
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2017
·Vol. 26
·期 11
·821-831
·
IF 1.422
Cheng Chuanjie,Li Yupeng,Zhang Xu,Li Jin
Global resource crisis and severe environmental problems have compelled world scientists to develop sustainable and green chemical materials. In this work, eugenol, a cheap and renewable phenol derivative found in cloves, is successfully utilized to prepare hydroxyl non-isocyanate polyurethanes (HNIPU), with number-average molecular weights ( M
n ) from several to dozens of kilodaltons. First, a diepoxide intermediate is synthesized through three steps in 43.9% total yield. Second, this diepoxide reacts with CO 2 at atmospheric pressure to form an intermediate possessing two cyclic carbonate groups in moderate yield. Third, the cyclic carbonate-containing intermediate further reacts, with compounds such as 4,4′-diaminodiphenyl methane, 1,6-hexanediamine and p -xylene diamine by nucleophilic ring-opening to obtain the desired HNIPUs. Furthermore, the diepoxide intermediate and CS 2 undergo addition reaction to form cyclic dithiocarbonate intermediate that further reacts with 4,4′-diaminodiphenyl methane to afford polythiourethane (PTU). The resulting PTU contains mercapto groups in its each unit. Number-average molecular weight of PTU is Mn 2800 Da. Finally, crosslinking reactions occur between the mercapto groups of PTU and crosslinkers (1,6-hexanediol acrylate and/or cardanol) by thiol-ene reactions under UV ( λ = 365 nm) irradiation conditions, leading to their corresponding crosslinked polymers. The optimized conditions for preparing crosslinked polymers include: PTU/cardanol/1,6-hexanediol acrylate = 1:1:0.05 (mass ratio), and UV irradiation time for 30 min. This work is expected to expand applications of eugenol and to provide a new route to NIPUs and PTUs using various diamines.
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CHEMICAL PHYSICS LETTERS
·
2017
·
IF 1.815
Shuning Liu,Chenchen Liu,Xinying Luan,Rui Yao,Yakai Feng
The far-red/near infrared photoluminescence of zinc phthalocyanines would be strongly quenched once they are aggregated, which will obviously hinder their wide applications in environmental, energy related and biomedical fields. Herein, the ultra-small sized semiconductor quantum dots with core-shell structures (CdSe@CdS) have been firstly synthesized and then assembled with a dendritic zinc phthalocyanine (ZnPc) in the H 2 O/DMF mixed solvent to obtain monodispersed nanospheres. Finally, it was found that the resultant ethanolic colloids can be employed as a sensitive and specific fluorescent nanoprobe for silver ions discrimination with a limit of detection (LOD) approaching to 10 − 8 mol/L.
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ACS Sustainable Chemistry & Engineering
·
2016
·
IF 5.267
Qiangqiang Zhu,Bin Wang,Tianwei Tan
For the effect of structural features on the catalytic performance of the conversion of ethanol and acetaldehyde to butadiene to be investigated, a series of MgO–SiO2 catalysts with different structural properties were synthesized by tuning the calcination temperature, investigated, and characterized. The best butadiene selectivity of 80.7% appears for the MgO–SiO2 catalyst calcined at 500 °C using a mixture of acetaldehyde/ethanol/water (22.5:67.5:10 wt %) as feed. Addition of the appropriate amount of water (10 wt %) improved butadiene selectivity by inhibiting the formation of 1-butanol and C6 compounds. Results from XRD, FT-IR, and 29Si MAS NMR indicate the generation of a significant amount of amorphous magnesium silicates along with few crystalline magnesium silicates for the catalyst calcined at 500 °C. XPS results indicate that it contains the lowest binding energies of both Si–O and Mg–O from Si–O–Mg bonds. For the catalysts calcined at low temperature (350 and 400 °C), more 1-butanol and C6 compounds formed, which are considered to be related to residual Mg(NO3)2. Additionally, more ethylene, diethyl ether, and butylene isomers were produced over the MgO–SiO2 catalyst calcined at 700 °C with the formation of forsterite Mg2SiO4. Further results from Fourier transform infrared spectroscopy after pyridine adsorption and CO2 temperature-programmed desorption show that the high catalytic performance is related to the presence of Lewis acidic sites and an intermediate number of basic sites.
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TETRAHEDRON
·
2015
·
IF 2.641
Xingzhu Xu,Haibo Wu,Zhengyi Li,Xiaoqiang Sun,Zhiming Wang
The development of bimetallic iron oxide-silver magnetic nanoparticles (Fe 2 O 3 –Ag MNPs) catalytic system provides an efficient heterogeneous synthetic pathway to allylic amines and 1,2-dihydroquinolines involving the direct inter/intramolecular nucleophilic substitution of π-activated alcohols with electron-deficient amines. The major advantages of the present method are wide substrate scope, simple product separation, low catalyst loading, and magnetically recyclable catalyst.
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ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
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2015
·Vol. 69
·期 4
·453-460
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IF 1.895
He Qun,Qin Li,Zhang Xuesheng,Wang Liansheng,Sun Ping,Wang Zunyao
Sediment and water samples collected from 8 sites of the Yangtze River in Nanjing section were characterized with 31 congeners of polychlorodibenzothiophenes (PCDTs). Concentrations and percentage compositions of these PCDTs in water and sediments were analyzed by gas chromatography–mass spectrometry. Results showed that ∑PCDT concentrations in sediments were higher (0.86–1.75 μg/kg) than those in water (0.56–1.30 μg/L). A linear relationship existed between ∑PCDT concentrations and total organic carbon content in sediments, whereas there was a poor linearity between ∑PCDTs concentrations and dissolved organic carbon content in water phase. Moreover, percentage compositions showed that penta-chlorinated DTs were the predominant congeners both in sediments and water. Differences existed in the percentage compositions between water and sediments. Highly chlorinated DTs accounted for a larger proportion in sediments than those in water. In conclusion, the present study showed the prevalent contamination by PCDTs in sediments and water from the Nanjing section of the Yangtze River.
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PubMed
高影响因子
ANALYST
·
2015
·Vol. 140
·期 17
·5944-5952
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IF 4.107
Shaoyan Zhou,Zheng Li,Xueju Lv,Bin Hu,Qiong Jia
Here, we synthesized a novel organic–inorganic hybrid material combining carboxylatocalix[4]arenes and magnetic zeolites by covalent bonding. The complex was characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction spectrometry, thermogravimetric analysis/differential thermal gravity analysis, and by using an X-ray photoelectron spectrometer and a vibrating sample magnetometer. The resulting magnetic composite was employed as a solid phase adsorbent to separate and preconcentrate synthetic phenolic antioxidants. Various interactions between the targets and the adsorbent contributed to the adsorption efficiency including hydrophobic interaction, hydrogen-bond interaction, and π–π complexation. The superparamagnetic participation in the process of synthesizing zeolites made the separation process of adsorbent from solutions convenient by an external magnetic field. Taking advantage of this property, this adsorbent could be recycled more than 30 times. The concentrations of the preconcentrated SPAs were determined directly by high-performance liquid chromatography. Various experimental parameters were optimized, according to which the method was evaluated. Finally, the prepared magnetic zeolite@carboxylatocalix[4]arene was successfully applied to identify synthetic phenolic antioxidants from juice and infant milk powder samples with high enrichment factors in the range of 41.9–92.5. The magnetic materials allowed rapid and simple preconcentration, implying their potential in the field of adsorption.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 131
·期 13
·
IF 1.64
Yang Cao,Lukuan Liu,Wanzhen Xu,Xiangyang Wu,Weihong Huang
The preparation of indole molecularly imprinted polymers (indole-MIPs) using 4-vinylpyridine as functional monomer, silica gel as matrix were used to adsorb indole from fuel oil specifically. The reverse atom transfer radical polymerization (RATRP) technology was introduced to prepare the surface molecularly imprinted polymers, and the precipitation polymerization was adopted in the preparation process. The obtained indole-MIPs were characterized by nitrogen adsorption, Fourier transform infrared spectrometry and scanning electron microscopy. The results show that indole-MIPs were provided with the larger surface areas and more pores. The adsorption capacity of indole-MIPs was 31.80 mg g −1 at 298 K, and the adsorption equilibrium was reached in a short time. The adsorption process was spontaneous by thermodynamic analysis, and an appropriate decrease in temperature could enhance the adsorption capacity. The adsorption process obeyed pseudo-second-order kinetic model by kinetics analysis. The isotherm analysis results show that both Langmuir and Sips equations were suitable to experimental data. The selective adsorption and reusable performance of indole-MIPs were favorable. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40473.
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Analytical Methods
·
2014
·Vol. 6
·期 17
·6651-6657
·
IF 1.938
Zhiyong Zhao,Suquan Song,Na Liu,Qinxiong Rao,Jiafa Hou,Sarah De Saeger,Aibo Wu
Food safety monitoring and toxicological research of mycotoxins are still in need of large quantities of high-purity deoxynivalenol (DON). To attain this purpose, a rapid, economical and reproducible purification method was developed for large-scale production of DON from rice culture inoculated with a DON-producing Fusarium graminearum strain JYH. The inoculated rice culture was first extracted with acetonitrile–water (84/16, v/v). The extracts were evaporated to dryness on a rotary evaporator after ethyl acetate partitioning and then dissolved in water followed by the final purification procedure through preparative high performance liquid chromatography and montmorillonite treatment. A combined approach of ultraviolet spectrometry (UV), ultra high performance liquid chromatography (UHPLC), mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy was applied for the multi-dimensional characterization of the target compound. As a result, the recovery of DON from the crude extract to the final product was up to 70%. An amount of 150 mg DON with the desirable purity of 98.93% could be obtained from 100 g of rice culture, which possessed identical immunochemical characteristics compared to a certified commercial DON standard. This proposed strategy might act as a valuable reference to obtain rather expensive compounds in a straightforward way.
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Catalysis Science & Technology
·
2015
·Vol. 6
·期 7
·2403-2412
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IF 5.426
Dong Wang,Yujun Zhu,Chungui Tian,Lei Wang,Wei Zhou,Yongli Dong,Qing Han,Yunfei Liu,Fulong Yuan,Honggang Fu
The introduction of a suitable co-catalyst is a promising way to improve the catalytic efficiency of Pt catalysts. Herein, SBA-15 modified with well-dispersed Mo2N nanoparticles (NPs) is synthesized by anchoring phosphomolybdic acid (HPM) on aminated SBA-15 (SBA-15-NH2) primarily, followed by nitridation treatment under NH3. After loading of Pt, the Pt–Mo2N/SBA-15 catalyst with close-contact Pt and Mo2N NPs can be formed. The intensive interaction of Pt and Mo2N benefited from the close contact is verified by XRD and XPS tests. As a result, the ternary Pt–Mo2N/SBA-15 catalysts have shown superior performance to Pt/SBA-15 catalysts for the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol. The TOF over the 1 wt% Pt–Mo2N/SBA-15 catalyst is close to that over the 3 wt% Pt/SBA-15 catalyst, but its selectivity to cinnamyl alcohol (COL) is 2.5 times that of 3 wt% Pt/SBA-15. The promoted activity of Pt–Mo2N/SBA-15 is mainly attributed to the synergistic effect of Pt and Mo2N NPs, which can cause the full development of the catalytic ability of Pt, thus reducing the Pt usage, through increasing the dispersion of Pt NPs and the fraction of Pt0 species in the catalyst.
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Food Analytical Methods
·
2015
·Vol. 9
·期 1
·88-94
·
IF 1.956
Jiao Zhe,Jiang Zhibin,Zhang Ni
In this study, copper(II) isonicotinate was first used as an online cleanup adsorbent in selective pressurized liquid extraction (SPLE) for determination of trace residues of polychlorinated biphenyls (PCBs) in fatty food samples. The adsorbent-to-sample ratio, extraction temperature, extraction time, recycle times, etc. were optimized. The PCBs in food samples of pork, chicken meat, and clam meat were detected by gas chromatography–mass spectrometry (GC-MS). The detection limit (S/N = 3) ranged from 0.2 ng/g wet weight (PCB 18) to 2.5 ng/g wet weight (PCB 66). Relative standard deviations (%RSDs) were lower than 12.5 %. The mean recovery was in the range of 82.4–105.1 %. Certified reference materials were analyzed with acceptable results. It was exhibited that the copper(II) isonicotinate showed higher purification capacity than other cleanup adsorbents for extraction of PCBs in fatty food. The proposed method which involved extraction-cleanup in one step can be a promising sample preparation method for food analysis.
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