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621.
Mojtaba Shamsipur Mahmoud Roushani Seied M. Pourmortazavi Nahid Shahabadi 《Central European Journal of Chemistry》2014,12(10):1091-1099
Electrocatalytic oxidation of sulfide ion on a glassy carbon electrode (GCE) modified with multiwall carbon nanotubes (MWCNTs) and a copper (II) complex was investigated. The Cu(II) complex was used due to the reversibility of the Cu(II)/Cu(III) redox couple. The MWCNTs are evaluated as a transducer, stabilizer and immobilization matrix for the construction of amperometric sensor based on Cu(II) complex adsorbed on MWCNTs immobilized on the surface of GCE. The modified GCE was applied to the selective amperometric detection of sulfide at a potential of 0.47 V (vs. Ag/AgCl) at pH 8.0. The calibration graph was linear in the concentration range of 5 µM–400 µM; while the limit of detection was 1.2 µM, the sensitivity was 34 nA µM?1. The interference effects of SO3 2?, SO4 2?, S2O3 2?, S4O6 2?, Cysteine, and Cystein were negligible at the concentration ratios more than 40 times. The modified electrode is more stable with time and more easily restorable than unmodified electrode surface. Also, modified electrode permits detection of sulfide ion by its oxidation at lower anodic potentials. 相似文献
622.
Seyed Mojtaba Amininasab Azad Rashidi Mehdi Taghavi Zahed Shami 《Polymer Science Series B》2016,58(6):712-719
Two series of new organosoluble and thermally stable polyimides containing anthracene, and fluorene pendants were prepared by a two-step solution polycondensation reaction of new synthesized diamines with commercially available dianhydrides. All intermediates and polymers were fully characterized by FTIR, NMR, and elemental analysis and their properties including solubility and thermal stability were studied. All the resulting polymers were amorphous with inherent viscosities ranged from 0.61 to 0.84 dL/g and were readily soluble in many organic solvents. 相似文献
623.
Soft and flexible chains of poly(tetramethylene glycol) (PTMG) were covalently grafted with multi-walled carbon nanotubes (MWCNT). FE-SEM images showed that the polyether PTMG formed a surrounding shell around the nanotubes with about 5 nm in thickness. The modified nanotubes (MWCNT-PTMG) were then loaded into an in situ prepared polyurethane elastomer (PUE) with different loading contents below 1 wt %. In addition to the modifier of MWCNT, polyether PTMG was also used for preparing the polyurethane matrix. Thermal analyses (TG/DTG and DTA) showed two endothermic phase transitions in associated with the two main thermo-degradations of the resulting PUE nanocomposites. Moreover, DMA technique exhibited an appreciable increase in the T g values due to a strong interaction between PTMG-modified MWCNT and PTMG-based PUE matrix. 相似文献
624.
Magnetic molecularly imprinted composite for the selective solid‐phase extraction of p‐aminosalicylic acid followed by high‐performance liquid chromatography with ultraviolet detection 下载免费PDF全文
Hasan Bagheri Karam Molaei Ali Akbar Asgharinezhad Homeira Ebrahimzadeh Mojtaba Shamsipur 《Journal of separation science》2016,39(21):4166-4174
A new method for the selective extraction of p‐aminosalicylic acid from aqueous and urine samples has been developed using magnetic molecularly imprinted polymer nanoparticles before determination by high‐performance liquid chromatography. The Fe3O4 nanoparticles were first prepared through the chemical coprecipitation of Fe2+ and Fe3+ and then coated with a vinyl shell. Subsequently, a layer of molecularly imprinted polymers was grafted onto the vinyl‐modified magnetic nanoparticles by precipitation polymerization. FTIR spectroscopy, scanning electron microscopy, vibrating sample magnetometry, and thermogravimetric analysis were applied to characterize the sorbent properties. Moreover, the predominant parameters affecting the magnetic solid phase extraction such as sample pH, sorption and elution times, the amount of sorbent, and composition and volume of eluent were investigated thoroughly. The maximum sorption capacity of the imprinted polymer toward p‐aminosalicylic acid was 70.9 mg/g, which is 4.5 times higher than that of the magnetic nonimprinted polymer. The magnetic molecularly imprinted polymer nanoparticles were applied for the selective extraction of p‐aminosalicylic acid from aqueous and urine samples and satisfactory results were achieved. The results illustrate that magnetic molecularly imprinted polymer nanoparticles have a great potential in the extraction of p‐aminosalicylic acid from environmental and biological matrices. 相似文献
625.
Maryam Mehdizadeh Omrani Nasim Kiaie Mojtaba Ansari 《Journal of Macromolecular Science: Physics》2016,55(6):617-626
Today, neurodegenerative diseases are very common among people. As a result, researchers are investigating methods for treatment of these diseases. One therapeutic approach is differentiating stem cells into neural cells to replace damaged areas of the brain. Cell attachment is the first, necessary step for the process of differentiation. Hence, we tried to enhance cell adhesion and proliferation of bone marrow stem cells on poly(?-caprolactone) (PCL) scaffolds through modifying this substrate with amine functional groups. The presence of amine groups was confirmed by Fourier transform infrared spectrometry (FTIR). Protein adsorption was measured at 280 nm via UV-spectrometry. The proliferation of differentiated neurons was assessed by 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (a dye) and cresyl violet staining. Finally, the morphology of differentiated neurons was shown by scanning electron microscopy (SEM). Results showed that amine modification of PCL scaffolds enhanced protein absorption and, consequently, cell adhesion and proliferation. 相似文献
626.
Taleshi MS Jensen KB Raber G Edmonds JS Gunnlaugsdottir H Francesconi KA 《Chemical communications (Cambridge, England)》2008,(39):4706-4707
Arsenic-containing hydrocarbons have been identified for the first time as natural components of fish oil. 相似文献
627.
Sahmsipur M Dastjerdi LS Alizadeh N Bijanzadeh HR 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,69(4):1265-1270
(133)Cs NMR spectroscopy was used to determine the stoichiometry and stability of the Cs(+) ion complex with dibenzo-21-crown-7 (DB21C7) in acetonitrile-dimethylsulfoxide (96.5:3.5, w/w) and nitromethane-dimethylsulfoxide (96.5:3.5, w/w) mixtures. A competitive (133)Cs NMR technique was also employed to probe the complexation of Na(+), K(+), Rb(+), Ag(+), Tl(+), NH(4)(+), Mg(2+), Ba(2+), Hg(2+), Pb(2+) and UO(2)(2+) ions with DB21C7 in the same solvent systems. All the resulting 1:1 complexes in nitromethane-dimethylsulfoxide were more stable than those in acetonitrile-dimethylsulfoxide solution. In both solvent systems, the stability of the resulting complexes was found to vary in the order Rb(+)>K(+) approximately Ba(2+)>Tl(+)>Cs(+)>NH(4)(+) approximately Pb(2+)>Ag(+)>UO(2)(2+)>Hg(2+)>Mg(2+)>Na(+). 相似文献
628.
Ehsan Rahmani Ali Ahmadpour Mojtaba Zebarjad 《Journal of Sol-Gel Science and Technology》2012,63(1):65-71
Multilayer of TiO2 and TiO2:SiO2 thin films were grown on a glass substrate by sol?Cgel processes, followed by high temperature treatment at 500?°C. The fine grained TiO2 films controlled by SiO2 dopant showed very good wear resistance and endurance life. Energy dispersive X-ray spectroscopy was used to indicate the elements in the films. X-ray diffraction analyses indicated that TiO2 and TiO2:SiO2 film contain only anatase phase. The morphologies of the original and worn surfaces of the samples were analyzed by means of scanning tunneling microscope and scanning electron microscopy. The tribological properties of TiO2 and TiO2:SiO2 thin films sliding against AISI52100 steel pin were evaluated on a pin on disk friction and wear tester. The results showed that 25-layer TiO2:SiO2 films are superior in reducing friction and resisting wear compared with the glass substrate. 相似文献
629.
Prof. Dr. Babak Karimi Dr. Dawood Elhamifar Omolbanin Yari Dr. Mojtaba Khorasani Prof. Hojatollah Vali Prof. James H. Clark Dr. Andrew J. Hunt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(42):13520-13530
The preparation and characterization of a set of periodic mesoporous organosilicas (PMOs) that contain different fractions of 1,3‐bis(3‐trimethoxysilylpropyl)imidazolium chloride (BTMSPI) groups uniformly distributed in the silica mesoporous framework is described. The mesoporous structure of the materials was characterized by powder X‐ray diffraction, transmission electron microscopy, and N2 adsorption–desorption analysis. The presence of propyl imidazolium groups in the silica framework of the materials was also characterized by solid‐state NMR spectroscopy and diffuse‐reflectance Fourier‐transform infrared spectroscopy. The effect of the BTMSPI concentration in the initial solutions on the structural properties (including morphology) of the final materials was also examined. The total organic content of the PMOs was measured by elemental analysis, whereas their thermal stability was determined by thermogravimetric analysis. Among the described materials, it was found that PMO with 10 % imidazolium content is an effective host for the immobilization of perruthenate through an ion‐exchange protocol. The resulting Ru@PI‐10 was then employed as a recyclable catalyst in the highly efficient aerobic oxidation of various types of alcohols. 相似文献
630.
Ghasem Marandi Malek Taher Maghsoodlou Nourallah Hazeri Reza Heydari Sayyed Mostafa Habibi‐Khorassani Niloufar Akbarzadeh Torbati Seyed Sajad Sajadikhah Danial Saravani Mansoureh Rakhshanipour Samira Gholamipour Faramarz Rostami‐Charati Brian W. Skelton Mohamed Makha Zeynab Zare Mojtaba Lashkari 《Heteroatom Chemistry》2011,22(5):630-639
The reaction between triphenyl or trialkyl phosphite and acetylenic esters in the presence of some heterocyclic or aromatic NH compounds such as thiazolidine‐2,4‐dione, 2‐methyl indole, 5‐bromoisatine, 3‐nitroacetanilide, saccharin, 5,5‐dimethylhydantoin, 2‐nitroaniline, 4‐nitroaniline, benzophenon hydrazine, and anthranilic acid led to the formation of phosphonato esters in high yield. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:630–639, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20725 相似文献