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21.
22.
In this study, synthesis, characterization and electrorheological (ER) properties of polyindene (PIN) and polyindene/kaolinite composites were carried out by cationic radical polymerization using FeCl3 as the oxidizing agent. The homopolymer and composites, containing different amounts of PIN were characterized by FTIR spectroscopy, thermo‐gravimetric (TGA) analyses, scanning electron microscopy (SEM) and dynamic light scattering (DLS) methods. The conductivity and dielectric properties of PIN and PIN/kaolinite composites were determined. Suspensions of PIN and PIN/kaolinite composites were prepared in silicone oil (SO), at a series of concentrations (c=5–25 m/m %). The effects of concentration, shear rate, electric field strength, frequency, temperature and promoter on ER activities of suspensions were investigated. 相似文献
23.
Pınar Talay Pınar Yavuz Yardım Zühre Şentürk 《Central European Journal of Chemistry》2013,11(10):1674-1681
This paper examined for the first time, the possibilities of the usage of a boron-doped diamond electrode for the redox behavior of rutin using cyclic and adsorptive stripping voltammetry. The cyclic voltammograms showed a pair of redox peaks at lower potentials followed by an irreversible oxidation peak at higher positive potential. Using square-wave adsorptive stripping voltammetry, the compound yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 4.0 at +0.48 V (vs. Ag/AgCl) (after 60 s accumulations at a fixed potential of 0.2 V). The calibration curve was linear in the concentration range from 0.01 µg mL?1 to 0.1 µg mL?1 (1.64×10?8 M ? 1.64×10?7 M). A detection limit of 0.0017 µg mL?1 (2.78×10?9 M) was observed without any chemical modifications and electrochemical surface pretreatments. As an example, the practical applicability of boron-doped diamond electrode was tested with the measurement of rutin in dietary supplement products. 相似文献
24.
AbstractA series of imidazole derivatives were synthesized from two-component condensation reaction of phenylgloxal monohydrate with guanylhydrazone. They were characterized by spectroscopic and analytical techniques. The in vitro anticancer evaluation of these compounds was done on human breast cancer (MCF-7) and human liver cancer (HepG2) cell lines using the MTT assay method. Most of the newly synthesized compounds displayed cytotoxic activity against these cancerous cells. In fact, compounds 3a, 3e, and 3?h exhibited more cytotoxic activities than the positive control drugs, fluro-5, and irinocam, against the MCF-7 cell line. Almost all the compounds, except for three, 3b, 3d, and 3f, gave more cytotoxic results than cisplatin. Therefore, these compounds could be considered for further development as anticancer drug candidates. 相似文献
25.
Serkan Yavuz Hamdi Özkan Gülçin Tok Ali Dişli 《Journal of heterocyclic chemistry》2013,50(6):1437-1440
The substituted pyrolidine derivatives with high stereoselectivity were obtained through cycloaddition reaction in the presence of a Lewis acid namely diethylzinc by solvent‐free grinding method. 相似文献
26.
Gülşah Kalaycı Murat Belivermiş Önder Kılıç Sayhan Topcuoğlu Yavuz Çotuk 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):239-244
This study was carried out to better understand the biokinetics of radiocesium in clams living in sediment. The accumulation and depuration kinetics of 134Cs were investigated in the Manila clam (Ruditapes philippinarum) under controlled laboratory conditions. The concentration factor was found to be 3.0 for 134Cs in the whole body; however, the concentration factor in the soft part of the clams (12) was significantly higher than those in the whole body and shell (0.80). The depuration kinetics of the radionuclide were described by a two-component exponential model for the whole body. The biological half-lives in the fast and slow components were found to be 0.63 and 22.1 days, respectively. The depuration kinetics for 134Cs in the soft parts were described by a single-component exponential model with a resultant the biological half-life of 18.0 days. 相似文献
27.
The article describes preparation of new calixarene biopolymers consisting of the immobilization of convenience calixarene derivative onto cellulose and chitosan biopolymers, and the encapsulation of these calixarene biopolymers with Candida rugosa lipase within a chemical inert sol–gel supported by polycondensation with tetraethoxysilane and octyltriethoxysilane. The catalytic properties of immobilized lipase were evaluated into model reactions employing the hydrolysis of p-nitrophenylpalmitate and the enantioselective hydrolysis of naproxen methyl esters from racemic prodrugs in aqueous buffer solution/isooctane reaction system. The resolution studies using sol–gel support have observed more improvement in the enantioselectivity of naproxen E?=?300 with Cel-Calix-E than with encapsulated lipase without calixarene-based materials. Furthermore, the encapsulated lipase (Cel-Calix-E) was still retained about 39 % of their conversion ratios after the fifth reuse in the enantioselective reaction. 相似文献
28.
Serkan Sayin Ilkay Hilal Gubbuk Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2013,75(1-2):111-118
The present study describes the preparation of a new calix[4]arene-based sporopollenin material and its application for the removal of Na2Cr2O7 from aqueous solution. The novel calix[4]arene-based sporopollenin material was prepared via the immobilization of dihydrazine amide derivative of p-tert-butylcalix[4]arene (3) onto the modified sporopollenin. The newly prepared calix[4]arene-based sporopollenin is characterized by using different analytical techniques such as FT-IR spectroscopy, scanning electron microscope and Elemental analysis. The batch wise sorption study was carried out to optimize various experimental parameters such as the effect of sorbent dosage, pH, temperature and Cr(VI) anion concentration. It has been found that the sorption of Cr(VI) anion on calix[4]arene-based sporopollenin was highly pH dependent and maximum sorption was achieved at pH 1.5. The sorption behavior was also evaluated by Langmuir, Freundlich and Dubinin Radushkevich isotherms. The value of correlation coefficient (R 2) showed a good agreement with Freundlich isotherm model. Result of study demonstrated that calix[4]arene-based sporopollenin proved to be highly effective for the removal of Cr(VI). 相似文献
29.
Three magnetically recoverable Brønsted acidic calix[n]arene derivatives were successfully constructed by immobilizing calix[n]arene sulfonic acids onto silica-coated magnetic nanoparticles, a process, which allows calix[n]arene derivatives to acquire magnetic properties. All of the magnetically recoverable Brønsted acidic calix[n]arenes efficiently catalyze the coupling of electron-rich arenes with some alcohols in water. After separation and recovery from the reaction mixture by a simple magnet, these Brønsted acidic calix[n]arenes can be recycled many times without losing their catalytic activity. 相似文献
30.
A novel triphenylamine based oxidative chemosensor TOC was synthesized. The chromogenic and fluorogenic behaviors of TOC towards Hg2+ and Cu2+ ions in a binary mixture of MeCN/H2O (9/1) were dramatically different. TOC displays colorimetric ‘naked eye’ recognition of Hg2+ and fluorogenic ‘turn on’ response towards Cu2+ via a unique cyclization reaction using two different detection modes. Moreover, TOCAZOL obtained from the oxidative cyclization reaction of TOC with Cu(ClO4)2 can be used as a selective fluorescent sensor toward Hg2+ ion. 相似文献