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Ionic liquids enhanced performance of PVC gels actuator
, Article Journal of Applied Polymer Science ; Volume 138, Issue 29 , 2021 ; 00218995 (ISSN) ; Latif, A ; Hussain, K ; Shehzad, F. K ; Ali, A ; Faisal, R ; Xudong, L ; Dias, O. A. T ; Weimin, Y ; Haoyi, L ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
Stimulated devices are highly demanded for actuators and artificial muscles in the recent era but susceptible to low deformation at an applied voltage. In the present work, ionic liquids (ILs) based gel films were prepared from the polyvinyl chloride (PVC), dibutyl adipate (DBA), 1-butyl, 3-methimidazolium chloride, and 1-pentyl-3-methylimidazolium hexafluorophosphate by a simple solvent evaporation method. The structural, morphological, optical, and mechanical properties of the composite PVC/ILs gel were characterized by Fourier-transform infrared spectroscopy (FTIR), Large Angle X-ray scattering (LAXS), UV–visible (UV–vis) absorption spectroscopy, scanning electron micrpscopy (SEM) and...
Fe 50Co 50 nanoparticles via self-propagating high-temperature synthesis during milling
, Article Powder Technology ; Volume 208, Issue 3 , 2011 , Pages 623-627 ; 00325910 (ISSN) ; Yourdkhani, A ; Koohestani, H ; Sadrnezhaad, S. K ; Asmatulu, R ; Sharif University of Technology
Abstract
Self-propagating exothermic reactions during mechanical milling of FeCl 3/CoCl 2 mixture together with sodium seeds resulted in formation of Fe 50Co 50 nanoparticles. Highly exothermic reactions resulted in temperature raise and formation of Fe 50Co 50 phase within the first 5min; however Fe 50Co 50 single-phase was obtained after 30min of milling. The products were characterized by XRD, SEM, EDS, TEM and VSM. Obtained results showed that both milling time and NaCl salt matrix affected the size, morphology, microstructure and magnetic properties of the produced particles
Chemical-Biological Phosphate Removal Using MBBR Bioreactors
, M.Sc. Thesis Sharif University of Technology ; Borgheei, Mahdi (Supervisor)
Abstract
Growing rate of eutrophication in receiving waters has made the enhancement of wastewater treatment plants to advanced methods of nutrients removal as necessary. Nitrogen and Phosphorus as the nutrients can reduce the quality of water and even make it unusable. Phosphorus is known to be one of the main reasons of eutrophication and creation of algal bloom. In this study, chemical-biological method for phosphate removal from the municipal wastewater is studied. Experiments are implemented for hydraulic retention times of 4, 8 and 16 hours, total intake concentration of phosphorus 7 ppm, COD 400 ppm and Nitrogen 25 ppm. Ferric Chloride as the precipitator chemical substance injected into the...
An Investigation on REEs' Cerium, Lanthanum, Neodymium Leaching from Phosphate Concentrate of Iron ore Waste in Hydrochloric Acid Environment and Study on Purification and Concentration of the Solution
, M.Sc. Thesis Sharif University of Technology ; Youzbashizadeh, Hossein (Supervisor)
Abstract
Considering the demand for electronic and other products that rare earth elements are one of the necessary materials for their production, recovery of these elements plays an important roll today.The term “rare earth”, represents a group of 17 metalic elements with similar physical and chemical properties such as Sc,Y and lanthanides. Lanthanides are a group of elements with 57 to 71 atomic numbers and all of them except Pr, are present in earth crust.Some of these elements are available in phosphate concentrate(iron ore waste) of chadormalu in bafgh. Base on the analysis performed on apatite concatrate, it was represented that Ce,La and Nd elements are more than the others. So this research...
Production of Gold with High Purity by Electrorefining Process
, M.Sc. Thesis Sharif University of Technology ; Yoozbashizadeh, Hossein (Supervisor)
Abstract
Gold is a noble and precious metal used in various industries, including jewelry, electrical and electronic, catalyst, and medical industries. Multiple processes are used to extract and refine gold; each one has its advantages and disadvantages. In this research Work, comprehensive information on the electrochemical purification process of gold from anode electrode with 75% crude gold and titanium cathode electrode in the chloride electrolyte solution is presented. To perform the purification process, first using the parameters and their levels, including temperature (30, 45, and 60 degrees Celsius), voltage (2, 2.2, and 2.4 volts), and acid concentration (1, 2, and 3 M), Design of...
Effect of hydrazine hydrate on the luminescence properties of MPA capped CdTe nanocrystals in hot injection method
, Article Journal of Luminescence ; Vol. 156, issue , 2014 , p. 235-239 ; Marandi, M ; Zare Bidaki, H ; Sharif University of Technology
Abstract
In this research MPA capped CdTe nanocrystals with sizes around 2.7-3.5 nm were grown in aqueous solution. The process was performed through the reaction of NaHTe with MPA and CdCl2 solution in high temperature. The synthesis was carried out in two different states of standard and modified forms. In the modified synthesis, the hydrazine hydrate material was added to the MPA plus CdCl2 solution before injection. The evolution of the nanocrystals size and PL quantum yield was monitored during the heating time for the growth. The results demonstrated that for the standard synthesis the growth rate was slow. The CdTe nanocrystals with high PL quantum yields were achieved in more than 10 h of...
Experiments design for hardness optimization of the Ni-Cr alloy electrodeposited by pulse plating
, Article Acta Metallurgica Sinica (English Letters) ; Volume 26, Issue 5 , 2013 , Pages 558-564 ; 10067191 (ISSN) ; Yousefi, E ; Dolati, A ; Mohammadi, M. R ; Sharif University of Technology
2013
Abstract
The hardness of the Ni-Cr alloy which is electrodeposited in chloride solution, is optimized by design of experiment method (central composite design). Various parameters were evaluated in order to find significant factors in this process. Frequency, duty cycle, current density and temperature were selected as effective factors. Analyses of variance (ANOVA) were performed on the results of the designed experiments. The best model which can predict the hardness of the Ni-Cr alloy electrodeposits was found whereas the frequency and quadratic behaviour of the current density were the most significant model terms. Serious interaction of the current density with frequency and duty cycle also were...
Photocathodic protection of 316L stainless steel by coating of anatase nanoparticles
, Article Protection of Metals and Physical Chemistry of Surfaces ; Volume 49, Issue 1 , January , 2013 , Pages 109-112 ; 20702051 (ISSN) ; Faghihi Sani, M. A ; Ghasemi, H ; Sharif University of Technology
2013
Abstract
Uniform nanostructure anatase films were coated on 316L stainless steel by the sol-gel dip coating method. Sols with different values of pH were applied. The corrosion protective behavior of coated samples was investigated by electrochemical measurements in 0.5 molar NaCl solutions on samples placed under UV illumination and dark condition using Tafel curves. It was found that in addition to acting as a physical barrier, anatase thin films are more protective under UV illumination due to photocathodic protection. Neutral sols give better protection due to formation of more uniform and less defective coatings
Activation of CX (=Cl, Br) bond in aryl halides toward the palladium-catalyzed Heck reaction using 2,6-bis(diphenylphosphino)pyridine
, Article Journal of Molecular Catalysis A: Chemical ; Volume 366 , January , 2013 , Pages 30-35 ; 13811169 (ISSN) ; Nadri, S ; Rafiee, E ; Jamali, S ; Joshaghani, M ; Sharif University of Technology
2013
Abstract
The 2,6-bis(diphenylphosphino)pyridine/palladium catalytic system successfully catalyzes the Heck coupling reaction of less reactive aryl chlorides as well as aryl bromides with styrene to give the corresponding olefins in reasonable yields. TBAB (tetrabutylammoniumbromide) as an additive was found to be essential for these reactions. The results of Heck reaction exhibited a high selectivity (>99/1) favoring the trans product
Potential of Calendula alata for phytoremediation of stable cesium and lead from solutions
, Article Environmental Monitoring and Assessment ; Volume 181, Issue 1-4 , Oct , 2011 , Pages 63-68 ; 01676369 (ISSN) ; Arjmandi, R ; Moogouei, R ; Sharif University of Technology
2011
Abstract
Calendula alata plants were tested for their potential to remove stable cesium and lead from solutions in a 15-day period. The plants were grown hydroponically and placed in solutions containing CsCl and Pb(C 2H 3O 2)2 at different concentrations (0.6, 2 and 5 mg l-1). When plants were incubated in CsCl solutions 46.84 ± 2.12%, 41.35 ± 1.59%, and 52.06 ± 1.02% cesium was found to be remediated after 15 days. Moreover, more than 99% lead was removed from the Pb(C 2H 3O 2)2solution in all three concentrations after 15 days during the same period. When both CsCl and Pb(C 2H 3O 2)2were supplemented together in the solution, 9.92 ± 1.22%, 45.56 ± 3.52%, and 46.16 ± 1.48% cesium and 95.30 ± 0.72%,...
Stereoelectronic effects: A simple yet powerful tool to manipulate anion affinity
, Article Organic and Biomolecular Chemistry ; Volume 13, Issue 7 , Dec , 2015 , Pages 2170-2176 ; 14770520 (ISSN) ; Fattahi, A ; Kass, S.R ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
Different strategies are employed in designing strong and selective anion receptors but stereoelectronic effects have been largely ignored. In this work, the stereo configuration of a non-interacting ether is found to have a large impact of more than two orders of magnitude on the binding of a rigid diol with tetrabutylammonium chloride in acetonitrile-d3. A favorable carbon-oxygen dipole and an intramolecular C-H⋯OH hydrogen bond in an equatorially substituted ether is found to be energetically more important than a stabilizing hydrogen bond in the corresponding axially oriented alcohol. IR spectroscopy is also used to probe the structures of the bound complexes and several binding motifs...
Investigation of salts behavior at liquid–liquid interfaces
, Article Springer Proceedings in Mathematics and Statistics, 26 August 2013 through 30 August 2013 ; Volume 117 , July , 2015 , Pages 265-270 ; 21941009 (ISSN) ; 9783319123066 (ISBN); 9783319123066 (ISBN) ; Bahramian, A ; Soltani, M ; Pourafshary, P ; Sarikhani, K ; Chen, P ; Ejtehadi, M. R ; Makarov R. N ; Melnik R. V. N ; Kotsireas I. S ; Shodiev H ; Cojocaru M. G ; Cojocaru M. G ; Makarov R. N ; Melnik R. V. N ; Kotsireas I. S ; Shodiev H ; Sharif University of Technology
Springer New York LLC
2015
Abstract
We have used molecular dynamics simulation to investigate hydrophilic– hydrophobic interfaces between calcium chloride (CaCl2) aqueous solutions and normal hexane. The results demonstrate the increasing impact of salt concentration on the liquid–liquid interfacial tension, hence, negative adsorption of CaCl2 according to Gibbs adsorption isotherm. Moreover, we calculated the density profiles of hexane, water, and the counter ions. The results reveal an electrical double layer near the interface and the less affinity of calcium cations toward the interface than that of chloride anions. Orientation of water molecules at the studied concentrations may result in developing a positively charged...
Prediction of water content of sour and acid gases
, Article Fluid Phase Equilibria ; Volume 299, Issue 2 , December , 2010 , Pages 171-179 ; 03783812 (ISSN) ; Azin, R ; Hassanzadeh, H ; Moshfeghian, M ; Sharif University of Technology
2010
Abstract
Estimating the feasibility of acid gas geological disposal requires the knowledge of the water content of the gas phase at moderate pressures and temperatures (typically below 50MPa, below 380K) and up to 6mol NaCl. In this paper, a non-iterative model is developed to predict the water content of sour and acid gases at equilibrium with pure water and brine. This model is based on equating the chemical potential of water and using the modified Redlich-Kwong equation of state to calculate the fugacity of the gas phase. The water content of pure CH4, CO2 and H2S are represented with average absolute deviations of less than 3.36, 7.04 and 8.4%, respectively. Experimental data of the water...
Morphology and magnetic properties of FeCo nanocrystalline powder produced by modified mechanochemical procedure
, Article Journal of Magnetism and Magnetic Materials ; Volume 322, Issue 21 , 2010 , Pages 3551-3554 ; 03048853 (ISSN) ; Sadrnezhaad, S. K ; Hasani, A ; Sharif University of Technology
2010
Abstract
Properties of FeCo nanocrystalline intermetallic powders prepared by salt-matrix hydrogen reduction of a milled Fe 2O 3-Co 3O 4 mixture were investigated. The product of 72 ks ball-milling at 350 rpm was CoFe 2O 4 nanopowder. Reduction of this powder for 3.6 ks by hydrogen at 750 °C resulted in the formation of Fe 0.67Co 0.33 stoichiometric compound. Scanning electron microscopy, electron dispersive spectrometry, X-ray diffraction and vibrating sample magnetometry were used to characterize the nanopowder. Using a salt-matrix (NaCl as a dispersion medium) resulted in the decrease of the reduction temperature and improvement of the morphology and magnetic properties of the nanopowder....
Production of extracellular protease and determination of optimise condition by bacillus licheniformis BBRC 100053
, Article Chemical Engineering Transactions ; Volume 21 , 2010 , Pages 1447-1452 ; 19749791 (ISSN) ; 9788895608051 (ISBN) ; Yaghmaei, S ; Haji Hosseini, R ; Sharif University of Technology
Abstract
The production of protease by Bacillus licheniformis BBRC 100053 was studied. The most appropriate medium for the growth and protease production is composed of: lactose 1 %, yeast extract 0.5 %, peptone 0.5 %, KH 2PO4 0.1%, MgSO4.7H2O 0.02 %. Enzyme production corresponded with growth and reached a maximums level (589 U/ml) during the stationary phase at 35 °C, pH equivalent to 10 and with 150 rpm after 73 hours. Protease activity was highest at pH 8 and 45 °C. The best carbon sources are respectively lactose and maltose and the best nitrogen source is peptone The protease was highly active and stable from pH 7.0 to 11.0 with an optimum at pH 7-8.Thermo stability of the enzyme was considered...
Improvements in permeation and fouling resistance of PVC ultrafiltration membranes via addition of Tetronic-1107 and Triton X-100 as two non-ionic and hydrophilic surfactants
, Article Water Science and Technology ; Volume 74, Issue 6 , 2016 , Pages 1469-1483 ; 02731223 (ISSN) ; Seyedi, S. M ; Rabiei, H ; Alvandifar, N ; Sharif University of Technology
IWA Publishing
Abstract
Two non-ionic and hydrophilic surfactant additives, Tetronic-1107 and Triton X-100, were added to poly(vinyl chloride)/NMP polymeric solution to prepare ultrafiltration membranes via immersion precipitation. Surfactants at three different weight percentages up to 6 wt% were added, and the fabricated membranes were characterized and their performance for water treatment in the presence of bovine serum albumin (BSA) as a foulant was assessed. The scanning electron microscopy images indicated remarkable changes in morphology due to higher thermodynamic instability after surfactant addition. The membranes are more porous with more macro-voids in the sub-layer. Plus, the membranes become more...
Evaluation of effect of temperature and pressure on the dynamic interfacial tension of crude oil/aqueous solutions containing chloride anion through experimental and modelling approaches
, Article Canadian Journal of Chemical Engineering ; 2017 ; 00084034 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Wiley-Liss Inc
2017
Abstract
The interfacial properties of crude oil are highly complex and are not yet well understood. This study aimed to evaluate the effect of temperature (30-80°C) and pressure (3.44-27.58MPa) on the dynamic interfacial tension (IFT) of crude oil/aqueous solutions consisting of 15000ppm of salt containing different chloride anions, e.g. NaCl, KCl, MgCl2, and CaCl2. To reach this goal, several parameters, such as dynamic and equilibrium IFT, adsorption time, diffusivity of resin, and asphaltene as surface-active agents from bulk of crude oil towards fluid/fluid interface and surface excess concentration of them at the interface, were compared as a function of temperature, pressure, and ion type. The...
Investigation of ionic liquids based on pyridinium and imidazolium as interfacial tension reducer of crude Oil−water and their synergism with MgCl2
, Article Journal of Petroleum Science and Engineering ; Volume 171 , 2018 , Pages 414-421 ; 09204105 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Abstract
Ionic liquids (ILs) can be tailored as chemical surfactants and surface active agents to reduce the interfacial tension (IFT) of crude oil/aqueous solutions for enhanced oil recovery processes. The current investigation was aimed to explore the nature of ingenious active agents in crude oil, including asphaltene and resin, and their possible interactions with two families of ILs, namely pyridinium and imidazolium, on the IFT of crude oil/aqueous solutions, both in the presence and absence of MgCl2. To the best of our knowledge, the effect of crude oil type on the IFT of crude oil/aqueous solution containing salts and IL has not been ever investigated. Accordingly, IFTs of light, medium and...
Improving survivability of lactobacillus plantarum in alginate-chitosan beads reinforced by Na-tripolyphosphate dual cross-linking
, Article LWT ; Volume 97 , 2018 , Pages 440-447 ; 00236438 (ISSN) ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
Abstract
In the present study, Lactobacillus plantarum PTCC 1058 was microencapsulated in Alginate-chitosan blended beads based on ionically dual cross-linking by Na-tripolyphosphate (Na-TPP). The homogenous solution of bacteria and alginate was dripped into the gelling bath of calcium chloride. After 30 min hardening, filtrate beads were transferred into the solution of chitosan. Dual cross-linked gel beads were prepared by employing Na-TPP solution to the chitosan coated beads. Morphology, particle size, alginate-chitosan interaction, characterizing the structure of single and dual cross-linked beads were determined by using scanning electron microscopy SEM, FTIR and XRD analysis. FTIR analysis...
Evaluation of effect of temperature and pressure on the dynamic interfacial tension of crude oil/aqueous solutions containing chloride anion through experimental and modelling approaches
, Article Canadian Journal of Chemical Engineering ; Volume 96, Issue 6 , 2018 , Pages 1396-1402 ; 00084034 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Wiley-Liss Inc
2018
Abstract
The interfacial properties of crude oil are highly complex and are not yet well understood. This study aimed to evaluate the effect of temperature (30–80 °C) and pressure (3.44–27.58 MPa) on the dynamic interfacial tension (IFT) of crude oil/aqueous solutions consisting of 15 000 ppm of salt containing different chloride anions, e.g. NaCl, KCl, MgCl2, and CaCl2. To reach this goal, several parameters, such as dynamic and equilibrium IFT, adsorption time, diffusivity of resin, and asphaltene as surface-active agents from bulk of crude oil towards fluid/fluid interface and surface excess concentration of them at the interface, were compared as a function of temperature, pressure, and ion type....