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排序方式: 共有327条查询结果,搜索用时 15 毫秒
321.
Somayyeh Piri Farideh Piri Bahare Rajabi Sahar Ebrahimi Abbasali Zamani Mohammad Reza Yaftian 《中国化学会会志》2015,62(11):1045-1052
Aluminum oxide/polyaniline nanocomposite is prepared by a new and one‐pot method including in situ electrooxidation of aluminum and electropolymerization of aniline. The product has been characterized by elemental analysis, FT‐IR spectroscopy, X‐ray diffraction (XRD), Field Emission Scanning Electron Micrographs (FESEM), and Transmission Electron Micrographs (TEM) techniques. ICP‐OES was used for determination of aluminum in the prepared nanocomposite. A porous structure of the prepared composite has been shown by FESEM images. TEM of the product confirms the presence of exfoliated aluminum oxide nanofibers. The adsorption potentials of the prepared nanocomposite towards Cu2+, Pb2+, Zn2+, Cd2+, Ni2+ and Co2+ ions were evaluated in batch adsorption experiments. The results show that the adsorption efficiency is controlled by aqueous phase pH. The experimental data was well interpreted by considering the Langmuir model. The kinetics of the adsorption processes can be well interpreted by pseudo‐second‐order equation. 相似文献
322.
S. J. Ahmadi N. Akbari Z. Shiri-Yekta M. H. Mashhadizadeh A. Pourmatin 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1701-1707
Hydrous, amorphous MnO2–ZrO2 composite was prepared as a new inorganic composite material under various conditions for removal of Sr2+ ion from aqueous solutions. The physico-chemical characterization was carried out by Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy and thermogravimetry. The maximum sorption capacity for synthesized composite was evaluated as 1.5 meq/g sorbent and batch experiments were carried out as a function of contact time, aqueous phase pH, temperature and initial metal ions concentration of adsorptive solution. The results indicated that under optimal conditions, Sr2+ ions could be efficiently removed using MnO2–ZrO2 composite from aqueous solutions when pH > 5. The equilibrium isotherms were determined and the sorption data were successfully modeled using Langmuir model. Kinetics of the process was studied by considering a pseudo second-order model. This model predicted chemisorption as the adsorption mechanism. The results of thermodynamic investigation reveal that the adsorption process of the studied ion is entropy driven. 相似文献
323.
Poly(ethylene glycol) dicationic ionic liquid‐based MnCl42? was prepared by nucleophilic substitution of poly(ethylene glycol) dichloride with methylimidazole followed by reaction with MnCl2. The structural properties of the catalyst were systematically investigated using Fourier transform infrared, UV–visible and Raman spectra and thermogravimetric analysis. The application of this catalyst allows the synthesis of a variety of benzyl thiocyanates and azides in high yield under reflux conditions in water. The main advantages of this method are its easy nature, rapidity, environmental benignity and high yields. 相似文献
324.
Amir Akbari Sarah Maghsoodi Amirhossein Shahbazi Kootenaei 《Journal of Dispersion Science and Technology》2019,40(1):17-24
This research aimed to evaluate the thermal viscosity, stability, conductivity and density of coolants including PEG-functionalized graphene nanoplatelets (GNPs) and gum Arabic (GA)-treated GNPs as a base fluid at various temperatures and concentrations. The present study explores the impacts of GNPs functionalized with poly ethylene glycol (PEG) on the colloidal stability and thermophysical properties of water-based PEG-functionalized GNPs suspensions as a new generation of heat transfer fluids. To this end, PEG-functionalized GNPs as a covalent sample and GA-treated GNPs were synthesized and their colloidal stabilities were traced via UV–vis spectrometry. After functionalized, colloidal stability results indicate less sedimentation for covalent samples (less than 10%) that that of noncovalent one (almost 20%) after a 15-day period. In addition, all the thermophysical properties e.g. thermal conductivity, density and viscosity were measured experimentally. Further, it has shown that by loading PEG-functionalized GNPs in the water, the increasing rate of the density and viscosity is not significant, while water-based GA-treated GNPs nanofluids showed higher rates of increase. Interestingly, the water-based PEG-functionalized GNP nanofluids at very low concentration significantly increase the thermal conductivity in comparison with that of non-covalent nanofluid at the same concentration and temperature and defiantly water. 相似文献
325.
In this investigation, the chemical compositions of berries from sea buckthorn were studied. The amount of ascorbic acid and β-carotene determined by HPLC was 170 mg/100 g FW and 0.20 mg/g FW, respectively. Total phenols, anthocyanins, acidity and total soluble solids (TSS) contents were 247 mg GAE/100 g FW, 3 mg/L (cyanidin-3-glucoside), 5.32% and 13.8%, respectively. Fruit antioxidant activity determined by the ferric reducing ability of plasma (FRAP) method was 24.85 mM Fe/100 g FW. Results confirmed the presence of six dominant fatty acids (determined by GC) in fruit including linoleic (34.2%), palmitoleic (21.37%), palmitic (17.2%), oleic (12.8%), linolenic (5.37%) and stearic acid (1.67%). Five dominant fatty acids of the seeds were linoleic (42.36%), linolenic (21.27%), oleic (21.34%), palmitic (6.54%) and stearic acid (2.54%). The nitrogen content was 3.96%. The P, K, Ca, Mg, Fe, Zn, Mn, Cu, Cd and Cl contents of fruit were 491, 1674, 1290, 990, 291, 29.77, 108.37, 17.87, 0.021 and 2.18 mg/kg DW, respectively. 相似文献
326.
The synthesis of NiO/NiCo2O4 nanoparticles by an eco-friendly, fast, simple and cost-effective approach employing Urtica extract is reported in this study. The NiO/NiCo2O4 nanocomposite were characterized using VSM, FTIR, XRD, and SEM techniques. Moreover, to construct a modified carbon paste electrode, NiO/NiCo2O4 were employed and this sensor was used for dopamine (DA) detection. Using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques, the electrochemical behavior of dopamine at the NiO/NiCo2O4/CPE was investigated. Analysis of dopamine, with a limit of detection (LOD) equal to 0.04 μM, in the concentration range of 0.1–100.0 μM, was facilitated by NiO/NiCo2O4/CPE. Moreover, the satisfactory selectivity for DA determination in the presence of uric acid (UA) and ascorbic acid (AA), was obtained. The suggested new sensor displayed a good reproducibility, sensitivity, and stability for determination of DA in drug and biological samples. 相似文献
327.
Farideh Jalilehvand Mikhail Maliarik Janos Mink Magnus Sandstroem Andrey Ilyukhin Julius Glaser 《ChemInform》2002,33(27):no-no
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献