eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
2993
3001
10.24200/sci.2017.4492
4492
Encapsulation of Keggin-type phosphotungstic acid into the mesopores of SBA-16 as a reusable heterogeneous catalyst for the epoxidation of olefins
M. Masteri-Farahani
1
M. Modarres
2
Faculty of Chemistry, Kharazmi University, Tehran, Iran
Faculty of Chemistry, Kharazmi University, Tehran, Iran
A heterogeneous catalyst for the epoxidation of olefins was prepared by encapsulating Keggin-type phosphotungstic acid (H3PW12O40) into the mesopores of SBA-16. After the encapsulation, the pore entrance size of SBA-16 was reduced through a silylation method to encompass the catalyst in the mesopores and allow the easy diffusion of the reactants and products during the catalytic process. The prepared catalyst was characterized by FT-IR and inductively coupled plasma-optical emission (ICP-OES) spectroscopies, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The analysis results revealed that the mesoporous nature of SBA-16 has been conserved after encapsulation of the catalyst and followed silylation step. The catalytic activity of the prepared material was assessed in the epoxidation of olefins with H2O2. The heterogeneous catalyst was recovered and reused up to five cycles without considerable decrease in activity
https://scientiairanica.sharif.edu/article_4492_15e9ac46132a78c5f4eb27503bdb216b.pdf
mesoporous SBA-16
heteropoly acid
Keggin
immobilization
Epoxidation
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3002
3013
10.24200/sci.2017.4491
4491
Synthesis of Nα-protected formamides from amino acids using MgO nano catalyst: Study of molecular docking and antibacterial activity
Raghavendra Mahadevaiah
1
Haraluru Shankaraiah Lalithamba
2
Sharath Shekarappa
3
Rajanaika Hanumanaika
4
Department of Chemistry, Siddaganga Institute of Technology, Tumakuru - 572 103, Karnataka, India
Department of Chemistry, Siddaganga Institute of Technology, Tumakuru - 572 103, Karnataka, India
Department of PG Studies & Research in Biotechnology & Bioinformatics, Kuvempu University, Shankaraghatta - 577451, Shimoga, Karnataka, India
Department of Studies and Research in Environmental Science, Tumkur University, Tumakuru - 572 103, Karnataka, India
Green synthesis of nano MgO particles and their application for the formylation of isocyanates of N-Fmoc/Cbz/Boc protected amino acids were reported. Nano magnesium oxide catalysed reaction of isocyanate with 96% formic acid has been established to obtain formamides. For this, the carboxyl group of protected amino acids were activated via mixed anhydride method and treated with NaN3. The formed azides were converted into its isocyanates through Curtius rearrangement and treated with HCOOH and catalytic amount of nano MgO. The advantages of this method were remarkably simple and economically low cost nano metal oxide under milder reaction conditions. Most importantly, MgO can be easily separated and other basic impurities were removed through a simple work-up. This protocol showed high efficiency in catalysing this transformation in a greener fashion. The molecular docking study of the synthesized compounds was performed against the macromolecules sortase-A and glucosamine 6-phosphate synthase to understand the binding interactions. The results of in vitro antibacterial activities of the synthesized compounds were supported by docking analysis.
https://scientiairanica.sharif.edu/article_4491_bdf6f4e18c0c042ea32691ac8041699d.pdf
Formamides
Nano MgO
Curtius rearrangement
Molecular docking
Antibacterial activity
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3014
3021
10.24200/sci.2017.4516
4516
Synthesis of quinoxalines promoted by eco-friendly nano-kaoline/BF3/Fe3O4 nano-catalyst under grinding condition
Bi Bi Fatemeh Mirjalili
fmirjalili@yazd.ac.ir
1
Marzieh Dehghani Tafti
2
Department of Chemistry, College of Science, Yazd University, Yazd, P.O. Box. 89195-741, Phone: +98 3531232672, , Fax: +98 38210644, I.R.Iran
Department of Chemistry, College of Science, Yazd University, Yazd, P.O. Box. 89195-741, Phone: +98 3531232672, , Fax: +98 38210644, I.R.Iran
Nano-kaoline/BF3/Fe3O4 as an eco-friendly nanocatalyst was used for quinoxaline preparation via condensation of 1,2-phenylene diamines and 1,2-diketones. This simple protocol proceeds under grinding condition and has many advantages such as easy workup and high product yields.
https://scientiairanica.sharif.edu/article_4516_18edcb9e291c6002a33a8da8873d3f57.pdf
1,2-Phenylene diamine
Benzil
Kaoline
Magnetic catalyst
Nano-kaoline/BF3/ Fe3O4
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3022
3031
10.24200/sci.2017.4513
4513
Pyridylmethylaminoacetic acid functionalized Fe3O4 magnetic nanorods as an efficient catalyst for the synthesis of 2-aminochromene and 2-aminopyran derivatives
Bagher Eftekhari-Sis
1
Masoumeh Sarvari Karajabad
2
Shiva Haqverdi
3
Department of Chemistry, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran
Department of Chemistry, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran
Department of Chemistry, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran
2-[(2-Pyridylmethyl)amino]acetic acid (PMAA) functionalized Fe3O4 superparamagnetic nanorods efficiently catalyzed three-component reaction of malononitrile, aromatic aldehydes and phenolic or enolic components, such as α-naphthol, β-naphthol, dimedone or kojic acid, to synthesize a variety of chromene or pyran derivatives in good to high yields. PMAA functionalized Fe3O4 magnetic nanorods were prepared via simple coprecipitation from an aqueous solution of Fe2+ and Fe3+ ions using NH4OH in the presence of glycine, followed by subjecting with 2-pyridine carbaldehyde and then NaBH4-mediated reduction of in-situ generated imine. Obtained nanorods were characterized by FT-IR, XRD, TGA, SEM, EDX, TEM, BET and VSM analysis.
https://scientiairanica.sharif.edu/article_4513_e5a94a6d01b4ec141f1caf60215f12cb.pdf
Fe3O4
Magnetic nanorods
Three-component reactions
Chromene
Pyran
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3033
3040
10.24200/sci.2017.4350
4350
Graphene oxide/SnO2 Nanocomposite as Sensing Material for Breathalyzers: Selective Detection of Ethanol in the presence of Automotive CO and Hydrocarbons Emissions
Maedeh Arvani
1
Hamide Mohammad Aliha
2
Abbas Ali Khodadadi
3
Yadollah Mortazavi
4
1Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, 11365-4563, Iran
Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, 11365-4563, Iran
Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, 11365-4563, Iran
Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, 11365-4563, Iran
SnO2 was ultrasonically deposited-precipitated in the presence of different amounts of graphene oxide (GO) prepared by the modified Hummers’ method. The resulting nanocomposites were used as the sensing material for detection of 1000 ppm CO and VOCs including ethanol, acetone and toluene and CH4 in a temperature range of 150-300°C. The nanocomposites were characterized by Raman spectroscopy, XRD, BET surface area measurement, FT-IR and SEM methods. It seems that SnO2 layers were deposited on the GO surface and incorporated into the matrix. This results in 47% increase in the nanocomposite BET surface area. Addition of 0.1 wt% GO to SnO2 increases the response to CO by about 6 times, at 300°C. As an optimum amount of 0.05 wt% GO is included in the SnO2, up to 2 fold enhancement in response to ethanol and toluene is observed. At 250oC, the highest response to ethanol is obtained, which is 120, 114, 1400 and 15 times larger than the responses to CO, toluene, methane and acetone, respectively, making the sensors quite selective to ethanol. Furthermore, this sensor exhibited good response in the low concentration of ethanol.
https://scientiairanica.sharif.edu/article_4350_4f419f90f4adb3a0445d60d87d8b38f8.pdf
Gas sensor
Graphene oxide
Breathalyzer
Ethanol
SnO2
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3041
3052
10.24200/sci.2017.4524
4524
Phenol Removal from Aqueous Solution by Adsorption Process: Study of The Nanoparticles Performance Prepared from Alo vera and Mesquite (Prosopis) Leaves
Mohammad Malakootian
1
Hossein Jafari Mansoorian
2
Mostafa Alizadeh
3
Abdolvahab Baghbanian
4
Environmental Health Engineering Research Center, Department of Environmental Health, Kerman University of Medical Sciences, Kerman,Iran
Environmental Health Engineering Research Center, Department of Environmental Health, Kerman University of Medical Sciences, Kerman,Iran
Department of Environmental Health Engineering, School of Public Health, Zahedan University of Medical Sciences, Zahedan, Iran
Lecturer and Research Fellow in Health policy and Economics, Health Systems and Global Populations, Faculty of Health Sciences, The University of Sydney, Sydney, Australia
This study was performed to measure the potential utilization of agro-waste to generate nanoparticles and evaluate the capability of it’s as a low cost adsorbent for removal of phenol. Adsorption studies for phenol removal by using Aloe vera and Mesquite leaves nanoparticles carried out under various experimental conditions including pH, nano-bioadsorbent dosage, phenol concentration, contact time, temperature and ionic strength in a batch reactor. The adsorption kinetics by pseudo-first order and pseudo-second order models and isotherm technique by Freundlich and Langmuir isotherms models were applied. The results showed that the rate of phenol adsorption increases in both nano-bioadsorbents with an increase of pH up to 7, adsorbent dosage up to 0.08 gL-1, phenol initial concentration up to 32 mgL-1, contact time up to 60 min and raising in temperature. The adsorption data followed the Freundlich isotherm model. The kinetic studies indicated that the adsorption of phenol with nano-bioadsorbents was best described by the pseudo second order kinetics. We found that the nanoparticles prepared from Aloe vera and Mesquite leaves had a high capability in adsorption of phenol, beside the point that they could be accessed at a low cost. These agro-wastes can be used to remove phenol from aqueous environments.
https://scientiairanica.sharif.edu/article_4524_6ee42395c97a7004e83ecccad053d72e.pdf
Agricultural solid waste
Aloe vera
Mesquite
Nanoparticle
Phenol Removal
Adsorption Isotherms
adsorption kinetics
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3053
3063
10.24200/sci.2017.4490
4490
Investigating the viscoelastic fluid behavior in hollow fiber membrane fabrication process using Giesekus' model
Hamid Didari
1
Mahdi Salami Hosseini
salami@sut.ac.ir
2
Reza Yegani
3
Chemical Engineering Department, Sahand University of Technology, Sahand New Town, Tabriz, Iran
Polymer Engineering Department, Sahand University of Technology, Sahand New Town, Tabriz, Iran
Chemical Engineering Department, Sahand University of Technology, Sahand New Town, Tabriz, Iran
In the present study, attempts are made to study the behavior of a viscoelastic fluid in hollow fiber membrane production process. For this purpose, the fluid is considered to obey the Giesekus’ model and flow is taken as steady, two-dimensional and isothermal flow. The flow field is obtained using DEVSS/SUPG scheme combined with a free surface tracking method. The obtained results are compared to the case of Newtonian fluid. It is shown that the extrudate swell is 20% more in the case of viscoelastic fluid. Moreover, the elastic behavior of the viscoelastic fluid significantly affects the velocity field in the extrudate outside the die. It causes the fluid flow to become reversed in the middle part of the extrudate as the direct result of the stress relaxation process, whereas such a behavior is not seen for Newtonian fluid. Also, the first normal stress difference (FNSD) distribution in the extrudate is obtained and its variation is discussed. Furthermore, the effect of operational parameters including die back pressure and take-up velocity are investigated. Finally, the predicted extrudate swell for various operation conditions is compared to experimental results showing a good agreement between experimental and simulated data.
https://scientiairanica.sharif.edu/article_4490_2c97b2c3f7cf04a3e6da859899961946.pdf
extrudate swell
Finite Element Method
Giesekus’ model
hollow fiber membrane
viscoelastic fluid
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3064
3073
10.24200/sci.2017.4573
4573
H2S Removal Using ZnO/SBA-3: New Synthesis Route and Optimization of Process Parameters
Amir Vahid
1
Mohammad Qandalee
2
Sahar Baniyaghoob
3
Research institute of petroleum industry, Tehran, Iran
Department of Basic Science, Garmsar branch, Islamic Azad University, Garmsar, Iran
Department of Chemistry, Faculty of Basic Science, Islamic Azad University, Science and Research Branch, Hesarak, Tehran, Iran
H2S is a major toxic compound that could be found in air, water, Fossil fuels and causes some worse effects such as acidic rain and corrosion. In the present work SBA-3 (Santa BarbarA University no. 3) with three different weight percent’s of ZnO, i.e. 5%, 10% and 15% was synthesized via an in situ approach. All synthesized samples were characterized using atomic absorption spectrometry, X-ray diffraction (XRD), nitrogen adsorption and transmission electron microscopy (TEM). The obtained results from XRD and nitrogen adsorption confirmed that all the samples almost retained their ordered structure after incorporation of ZnO nanoparticles within the mesopores of SBA-3. TEM images show that ZnO nanoparticles arranged along the direction of mesopores of SBA-3. Then, adsorption of H2S from a model gas was investigated. A three factor Box–Behnken design with five center points and one response was performed for the evaluation of effect of three process parameters, i.e. ZnO wt%, space velocity and temperature on the adsorption of H2S and a quadratic model (r2 : 0.9185) was developed to navigate the design space. Temperature had the largest and space velocity had the lowest effect on the breakthrough of H2S. The optimum breakthrough time (tbp) was 588 min.
https://scientiairanica.sharif.edu/article_4573_e90c90ad8df58c7de07f4208f887b54e.pdf
air pollution
H2S
Mesoporous materials
Removal
Zinc oxide
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3074
3080
10.24200/sci.2017.4527
4527
INVESTIGATION OF THE EFFECTS OF CARBONIC AGENT AND NANOCLAY ON THE PROPERTIES OF THE POLYLACTIC ACID BASED NANOCOMPOSITES
Meral COBAN
1
Seda HAZER
2
Ayse AYTAC
3
Department of Chemical Engineering, Engineering Faculty, Kocaeli University, 41380, Kocaeli,Turkey
Department of Chemical Engineering, Engineering Faculty, Kocaeli University, 41380, Kocaeli,Turkey
Department of Chemical Engineering, Engineering Faculty, Kocaeli University, 41380, Kocaeli,Turkey
The objective of this study is an investigation of the effects of carbonic agent and nanoclay loading level on the properties of the added flame retardant and plasticized polylactic acid (PLA) composites. Pentaerythritol (PER) was used as a carbonic agent in the composites. The flammability behaviour of these composites was investigated with the increasing nanoclay loading level. Flame retardant properties of plasticized PLA composites which are consisting of PER and nanoclay as a synergistic agent were evaluated. While the nanoclay loading levels were changed between 1-5 wt% of these samples, PER loading levels were fixed at 2 wt%. Besides, effects of increased PER loading level were also investigated with 3 wt% clay loading. Samples were produced by using extrusion and injection molding techniques. The morphological, thermal and mechanical properties were studied. The flammability was evaluated by using limiting oxygen index (LOI) and vertical burning test (UL-94). The results showed increased PER level didn’t significantly change LOI values of the PLA based nanocomposites. In addition, the highest LOI value was observed as 32 for 1 wt% nanoclay including sample. While adding PER to the PLA/PEG/TPP increased the elongation at break value, adding of the nanoclay decreased this value for nanocomposites.
https://scientiairanica.sharif.edu/article_4527_38f3c1eccc447009cf7b269bc8b015c9.pdf
poly(lactic acid)
flame retardant
triphenyl phosphate (TPP)
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2017-12-01
24
6
3081
3086
10.24200/sci.2017.4523
4523
Toxic Effects of Chronic Feeding with Food Azo Dyes on Drosophila melanogaster Oregon R
Handan Uysal
1
Sıdıka Genç
2
Arif Ayar
3
Department of Biology, Faculty of Science, Atatürk University, 25240, Erzurum, Turkey
Department of Biology, Faculty of Science, Atatürk University, 25240, Erzurum, Turkey
Sabuncuoğlu Şerefeddin Health Services Vocational School, Amasya University, 05100, Amasya, Turkey
Artificial azo dyes are widely used as coloring agents for foodstuffs, drugs and cosmetics. In this study, the toxic effect of four different synthetic food dyes (Ponceau 4R, Sunset Yellow, Amaranth, Tartrazine) on 72±4h larvae of Oregon (R) wild type of Drosophila melanogaster were investigated. In addition, depending on chronic feeding, the life span of the flies determined. For this purpose, six different concentrations of the food dyes (5, 10, 15, 20, 25 and 30 mg mL-1) were selected by preliminary studies to determine the LD100 values.The effects of the food dyes on longevity were studied separately in female and male populations. It was determined that the maximum mean life span of the female and male D. melanogaster populations decreased with increasing concentrations of food dyes. Based on the results obtained from the larval mortality and life span experiments, the order of toxicity for food dyes was Tartrazine>Amaranth> Sunset Yellow ≥ Ponceau 4R.
https://scientiairanica.sharif.edu/article_4523_ea46e8cc5bc59bf81eb4cbf1c15c6778.pdf
Drosophila melanogaster
Food Azo dyes
Longevity
Larval mortality
Toxic effects