فهرست مطالب khodabakhsh niknam

In the current research, NaY zeolite with a molar ratio of Si/Al=2.5 was grafted chemically with amines like monoethanolamine, tetraethylenepentamine, and morpholine.The modified NaY zeolites were characterized by XRD, FT-IR, TGA, EDAX, BET, FESEM, CO2-TPD, and Volumetric analysis. Modification of the NaY surface with amine groups led to a remarkable rise in CO2   adsorption capacity. CO2 adsorption studies of  NaY and modified NaY zeolite by CO2-TPD technique revealed that, the dominant mechanism involves the interaction of CO2 with amine groups on the surface of NaY zeolite, at ambient pressure and at a temperature of 323 K. The volumetric method was also used to investigate CO2 adsorption onto the amine grafted NaY zeolite at 5, 7 bar pressures and at temperatures of 298 and 343 K. The adsorption process is thermal dependence and results of adsorption studies indicate that increasing temperature leads to higher adsorption of CO2 onto the amine grafted NaY zeolites.

The purpose of this research was possibility evaluation of indirect use of Ag-NPs-coated porous ceramic in water filtration of culture system of shrimp post larvae to control Vibrio harveyi. After confidence of antibacterial activity of Ag-NPs-coated on porous ceramic against mentioned bacteria via in vitro experiments (Zone of inhibition test and Test tub test), porous ceramic filter media used for water treatment. Therefore, the performance of the Ag-NPs-coated on porous ceramics in removing pathogenic bacteria was studied in two phases: in the first phase, V. harveyi (1.5*108 cfu/ml) was inoculated to the water and efficacy of filters of inhibition of bacteria was evaluated via total count of bacteria in the test water; in the second phase, the performance of the Ag-NPs-coated on porous ceramic was tested in the presence of shrimp larvae and efficacy of filters in inhibition of bacteria was evaluated via total count of bacteria, mortality rate, clinical signs, and also hepatopancreas and muscle culture. Based on the results, the highest zone of inhibition obtained in presence of Ag-NPs-coated porous ceramic modified by an aminosilane coupling agent, 3-aminopropyltriethoxysilane (APTES) (The samples were immersed in the silver colloidal solution for 24 h).The results of flow test showed the highest bacteria removal efficiency from water with complete (100%) removal of the targeted pathogen in the flow rate of 1 L/min. In the second phase, the results indicated significant difference in decreasing of water bacteria, shrimp mortality and disease symptoms in treatment containing silver compounds compare to controls.

Silica-bonded N-propyldiethylenetriamine (7) is employed as a recyclable heterogeneous solid base catalyst for the synthesis of 2-amino-3,5-dicarbonitrile-6-thiopyridines through pseudo four-component condensation reaction between aromatic aldehydes, malononitrile, and 2-amino-thiophenol in refluxing ethanol. Silica-bonded N-propyldiethylenetriamine showed much the same efficiency when used in consecutive reaction runs.

Several samples of mesoporous silica were prepared via sol-gel chemistry in the presence of CTAB as template with variation of stirring intensity and aging time, ratios of CTAB/SiO2 and NH4OH/H2O in synthesis mixture. Effects of aging temperature, hydrothermal treatment and ter-Butanol addition to the synthesis mixture on the textural properties of obtained samples were also studied. Results of XRD, SEM, and N2 adsorption isotherm analyses shows particle size and morphology of mesoporous silica are influenced by synthesis conditions; although no significant change of pore size (

Nanotechnology is a field of applied science and technology covering a broad range of topics. Use of nanotechnology and especially silver nanoparticles in control of bacterial diseases and infections has been studied in the recent years. The aim of the present study was to investigate the in vitro antibacterial effect of filter media coated with silver nanoparticles against Bacillus spp.
In this research, first, the antibacterial effects of silver nanoparticles against mentioned bacteria were evaluated by microdilution method in Broth medium. After confidence of inhibitory effect of colloidal silver nanoparticles, antibacterial effect of filter media coated with silver nanoparticles was evaluated via in vitro microbiology tests (zone of inhibition test and test tube test).
Present study showed that colloidal silver nanoparticles have good antimicrobial effects against tested bacteria, so that MIC and MBC of silver nanoparticles for Bacillus spp. were calculated 3.9 and 31.25 mg/L, respectively. Also significant decrease was observed in bacterial growth after exposure to filter media coated with silver nanoparticles in test tube test and zone of inhibition test (P≤ 5%).
The results of this research indicate that filter media coated with silver nanoparticles have considerable antimicrobial effects; therefore they could possibly be used as excellent antibacterial water filters and would have several applications in other sectors.

A sequential process strategy was introduced for the synthesis of 2,3,4,5-tetrasubstituted pyrroles by the formation of benzoin from the corresponding aromatic aldehyde and followed by condensation reaction with 1,3-dicarbonyl compounds and ammonium acetate in the presence of diethylene glycol-bis(3-methylimidazolium) dihydroxide as catalyst in refluxing ethanol. The recycled catalyst could be reused four times without appreciable loss in the catalytic activity.

A sensitive and selective solid phase extraction procedure for the determination of traces of Cd(II),Zn(II) and Ag(I) ions has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with2,3 Di Hydro 2,3 para tolyl Qinazoline (1 H)- 4 one (DPTQO). The influences of the analyticalparameters including pH and sample volume were investigated. Common coexisting ions did notinterfere on the separation and determination of analytes under study. The adsorbed analytes weredesorbed by using 6mL of 4 mol L1 nitric acid. The responses are linear 0.02–0.85 g mL-1 for Cd2+ion 0.01–0.90 g mL-1 for Zn2+ and 0.02–0.92 g mL-1for Ag+ detection limit for Cd(II), Zn(II) andAg(I) ions were found to be 1.4, 1.3 and1.12 (ng mL-1), respectively. It was found that the recoveryfor Cd2+, Zn2+and Ag+ ions were 97.7, 98.2 and 98.0 with RSD of 1.9, 1.8 and 1.7. It was alsoobserved that recovery for repeated recovery on the same solid phase not varies more than 3%. Thepresented procedure was successfully applied for determination of analytes in radiology wastewater,amalgam, natural water and blood samples.

Silica-bonded N-propyldiethylenetriamine sulfamic acid (SPDTSA) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines  through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines  at room temperature under solvent-free conditions. SPDTSA showed much the same efficiency when used in consecutive reaction runs.

Silica-grafted n-propyl-diaza-15-crown-5 (SGPDC) with immobilized palladium nanoparticles was found as an efficient heterogeneous catalytic system for the Heck and Suzuki coupling reactions and satisfied results were obtained. Different derivatives of aryl halides and alkenes under the Heck reaction were converted to the corresponding products with good efficiency. The presence of electron-donating groups on the aryl moiety of aryl halide derivatives retarded the reaction and led to the drop of yields. In contrast, higher efficiency was observed when electron-withdrawing groups were accommodated on the aryl halide. As well as, a variety of bi-phenyl derivatives were well synthesized by the coupling reaction between aryl halides and aryl boronic acids derivatives via the Suzuki reaction. Reusability of the catalyst was examined in both Heck and Suzuki reactions under optimized conditions. The catalyst could be recycled several times without any treatment in its catalytic activity. The TEM image of the catalyst utilized in the Heck reaction after seven times of recyclability indicates that the morphology and size of the nanoparticles have remained almost intact.

Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. The heterogeneous solid acid showed much the same efficiency when used in consecutive reaction runs.

Silica-bonded n-propyltriethylene-tetramine (SBNPTT) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes. Chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oC under solvent-free conditions. The heterogeneous solid base showed much the same efficiency when used in consecutive reaction runs.

A simple and efficient procedure for the preparation of 3-propyldiethylenetriaminesilica (PDTAS) by reaction of 3-chloropropylsilica with diethylene-triamine is described. 3-Propyldiethylenetriaminesilicais employed as a recyclable base catalyst for the synthesis of 2-amino-4,6-diarylnicotininitrilefrom the reaction of acetophenone derivatives, aromatic aldehydes, malononitrile, and ammonium acetate under solvent-free conditions at 100 oC. The heterogeneous solid base catalyst was recycled for four runs upon the reaction of 4-chloroacetophenone, 4-chloroenzaldehyde, malononitrile, and ammonium acetate without losing its catalytic activity.

Sulfuric acid {[3-(3-silicapropyl)sulfanyl]propyl}ester (SASPSPE) is employed as a recyclable catalyst for the synthesis of α-amino nitriles. These syntheses were performed via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide under mild reaction conditions at room temperature. The catalyst could be recycled and reused several times without any loss of efficiency.

In this research, different alcohols and phenols are subjected to the reaction with HMDS in the presence of ionic liquid and silica-supported catalysts. Silylation was accomplished under mild reaction conditions at room temperature in short reaction times and good to excellent yields.

The one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by tandem Knoevenagel-Michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid catalyst was reported. SBPPSA showed much the same efficiency when used in consecutive reaction runs.

Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl]ester (SASPSPE) is employed as a recyclable catalyst for the silylation of hydroxyl groups. A good range of primary, secondary alcohols and phenolic hydroxyl groups were effectively converted into their corresponding trimethylsilyl ethers with examethyldisilazane in the presence of catalytic amounts of SASPSPE at room temperature with short reaction times in good to excellent yields. This heterogeneous catalyst was recycled for nine runs without losing its catalytic activity.