Mojtaba Shamsipur
Department of Chemistry, Razi University, Kermanshah, I.R. Iran
[ 1 ] - Synthesis and Properties of Plasticized Sulfur-Montmorillonite Nanocomposites by Melt-Blending
Plasticized sulfur/montmorillonite nanocomposites were prepared by the melt-blending method and the dispersion of montmorillonite (MMT) and the mechanical properties of the nanocomposites were studied. Natural sodium montmorillonite (NaMMT) and organically modified montmorillonite (OMMT) were used as filler. Scanning electron microscope (SEM), X-Ray powder Diffraction (XRD...
[ 2 ] - Influence of Micro and Nano Silica on Mechanical Properties of Plasticized Sulfur Composites
In this paper the influence of two different sizes of silica particles (micro-silica and nano-silica) was studied on mechanical properties of sulfur and sulfur composite. To improve the structural properties, sulfur was plasticized using dicyclopentadiene (DCPD) and methyl styrene (MSt). Plasticized sulfur composite was prepared by melt blending of plasticized sulfur and silica particles. T...
[ 3 ] - The Study of Chemiluminescence of Acridinium Ester in Presence of Rhodamin B as a Fluorescer
The reaction of hydrogen peroxide and pheny -9-acridinecarboxylate in the presence of rhodamin B as a fluorophore leads to the emission of either bright blue light or bright red light, depending on the structure of fluorescer and reaction conditions. The light emitter responsible for the Chemi Luminescence (CL) reaction is acridone and that the blue light produced with out the fluorescers...
[ 4 ] - Potassium-Selective Membrane Sensor Based on Two Recently Synthesized Poly(oxyethylene) Derivatives
Two poly(oxyethylene) derivatives 1.10-bis(2'-benzoic acid)-1,4,7,1-tetradecane (L1) and 1,7-bis(2'-benzoic acid)-1,4,7-trioxaheptane (L2) were used as suitable ionophores for the preparation of potassium-selective PVC-membrane electrodes. The resulting electrodes based on L1 and L2 exhibit linear responses to the activity of K+ ions within the concentration ranges of 3.1<em...
[ 5 ] - Spectroscopic Study of the Complexation of Meso-Tetraphenylporphyrin with -Acceptors DDQ and TCNE in Chloroform Solution
Formation of the molecular complexes between meso-tetraphenylporphyrin (TPP) and the p-acceptors 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and tetracyanothylene (TCNE) in chloroform solution was investigated spectrophotometrically. The formation constants of the resulting 1:1 molecular complexes were determined using the Benesi-Hildebrand and Nash methods. The TPP-DDQ pro...
[ 6 ] - Influence of Metal Ion Complexation on the Acid Dissociation of 4'-Carboxybenzo-24-Crown-8 in an Ethanol-Water Mixture
A spectrophotometric method was used to determine the acidity constant of 4'-carboxybenzo-24-crown-8 in 52% (w/w) ethanol-water mixture. The acid dissociation constant, Ka, was found to increase in the presence of Na+, K+, Rb+, Cs+ and Tl+ ions. The formation constants of the resulting 1:1 complexes between the carboxycrown a...
[ 7 ] - Polarographic Study of the Interactions between Thallium and Lead Ions and Some Crown Ethers in 90% Acetonitrile and 90% Ethanol Solutions
The complexation reactions between Tl+ and Pb2+ ions and crown ethers 12-crown-4(12C4), 15-crown-5 (15C5), benzo-15-crown-5 (B15C5), 18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6) and aza-18-crown-6 (A18C6) were studied in 90% acetonitrile and 90% ethanol solutions at 25 °C, using an a.c. polarographic technique. The stoichiometry and stability of the complexes we...
[ 8 ] - Extraction-Fluorimetric Determination of Trace Amounts of Mercury by 1,10-Diaza-18-Crown-6 and Rose Bengal
A simple and sensitive extraction-fluorimetric method for the determination of mercury is reported. The method is based on the quantitative extractionof a ternary crown-mercury-rose Bengal complex into chloroform at pH 10 followed by fluorimetric measurements at 580 nm. A linear working range from 0.05 to 2.00 mg/mL is obtained. The relative standard deviation for 1.0 </em...
[ 9 ] - Catalytic Spectrophotometric Determination of Traces of Tellurium (IV)
A Simple, rapid and sensitive method has been developed for determination of trances of tellurium (VI) (0.096-1.250 mg/mL) based on its catalytic effect on the reduction reaction of toluidine blue by sulfide ion at pH 4. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the dyestuff at 628 nm by the fixed time method. The detection...
[ 10 ] - Extraction-Fluorimetric Determination of Low Levels of Copper by 1,7- Diaza-15-Crown-5 and Rose Bengal
A simple and sensitive extraction-fluorimetric method for the determination of copper is reported. The 1,7-diaza-15-crown-5-copper-rose Bengal (DA15C5-Cu-RB) ternary complex is quantitatively extracted into chloroform, diluted with ammoniacal acetone and its fluorescence intensity is measured at 570 nm with excitation at 540 nm. A linear calibration graph was obtained over the copper concen...
[ 11 ] - Flow Injection Spectrophotometric Determination of Sulphide by Catalytic Reduction of Toluidine Blue
Sulphide was determined spectrophotometrically at 628 nm and pH 6.7 based on its catalytic reduction of toluidine blue in the presence of Se(IV) using a flow injection system. After optimization of the measuring conditions the calibration curve was found linear up to 25 mg/mL and the detection limit was 0.3 mg/mL (30 mL injections). The ...
[ 12 ] - Extraction of Traces of Copper as Tetra-Butylammonium Tetrathiocyanato Copper (II) and Its Spectrophotometric Determination Using Eriochrome Black T
An extraction-spectrophotometric method for the determination of traces of copper (II) is described. The method is based on the quantitative extraction of copper as tetrabutylammonium tetrathiocyanato copper (II) into methyl isobutyl ketone, followed by spectrophotometric determination, using eriochrome black T as a metallochromic indicator. The red-violet mixed complex of copper absorbs at...
[ 13 ] - NMR Study of Benzo-15-Crown-5 Complexes with 7Li+ and 133Cs+ Ions in Nonaqueous solvents
Complexes of benzo-15-crown-5 macrocycle with Li+ and Cs+ ions were investigated by 7Li and 133Cs NMr in a number of nonoqueous solutions. The resulting 1:1 complex with Li+ ion was found to be much more stable than that with Cs+ ion. With the exception of pyridine solutions the stabilities of the complexes varied inversely w...
[ 14 ] - A Biotechnological Perspective on The Affinity Magnetic Separation and Purification Based on Oligonucleotides
The rapidly growing field of biotechnology has created a critical need for simple, fast andhigh-throughput processes for the separation and purification of biomolecules from biologicalmatrices. In recent years, several bioseparation techniques have been proposed as advancedalternatives to the classical separation methods. These modern processes emphasize ultrahighselective and sensitive analysi...
[ 15 ] - تعیین مشخصه های سینتیکی و ترمودینامیکی واکنش نور تابی دو مشتق جدید تری آزین در سیستم پراکسی اگزالات
در این کار نورتابی شیمیایی ناشی از واکنش تری کلرو پر اکسی اگزالات با هیدروژن پراکسید در حضور دو مشتق تری آزین به عنوان لومینوفور بررسی شده است. تاثیر غلظت تری آزین، هیدروژن پراکسید، پراکسی اگزالات، دما، غلظت و نوع کاتالیزور بررسی شده است. مشخصههای سینتیکی نورتابی شیمیایی از طریق مطابقت نتایج تجربی شدت نورتابی- زمان نشر، استخراج شده است. مشخصههای ترمودینامیکی فرایند نظیر انرژی فعالسازی و تابع ...