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Research field: synthesis of polymeric and ceramic membranes
Expert: Javeri
Phone:
Address: Chemical Engineering Department, 4th flour No. 451
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Strong adhesion of nanoparticles (NPs) onto the membrane surface to provide the prolonged effects during membrane filtration has been always challenging. In this work, polydopamine (PDA) was utilized to increase adhesion of titanium dioxide (TiO2) NPs onto the polyethersulfone (PES) ultrafiltration membrane. For this aim, polymerization of PDA on the membrane surface was followed by the NPs deposition (0.1 and 0.5?wt. %). Washing and wiping analyses were utilized to evaluate the strength of NPs adhesion onto the membrane surface, before and after the pre-modification of PES membrane with PDA. Scanning electron microscopy (SEM) images revealed that increment of NPs concentration as well as deposition time of PDA resulted in the increase of a
Investigations on a variety of methods for reducing the viscosity of heavy crude oil show that conventional methods due to their high temperature and pressure are expensive, unsafe, costly maintenance with huge utility and low efficiency. Thermal cracking was the first method of reducing viscosity, which presence of catalysts could improve some of its problems such as instability and extremely high temperatures. But temperature was still high and due to these basic problems, efforts are continuing to achieve better result and more efficiency. Usage of dispersed nanocatalysts greatly increased the efficiency of these reactions so that at presence of hydrogen and nano dispersed catalyst viscosity reduced up to 99%. Many nanocatalysts have bee
A successful immobilization of 1-octyl-3-methylimidazolium tetrachloroferrates ([Omim][FeCl4]) thin films on a silica gel while remaining its mesoporousity, was accomplished in this work. The developed catalyst was highly active and cost-effective for deep oxidative desulfurization of refractory thiophenic compounds at room temperature utilizing H2O2 oxidation agent. The reaction products were well separated from fuel by the catalyst itself under a beneficial solvent-free condition. The catalyst was characterized applying different analyses of FT-IR, TGA, XRD, SEM, EDS, AFM, N2 adsorption desorption, BET, and BJH. A sufficiently large pore diameter (∼6.2 nm) and high surface area (∼490 m2/g) of the silica gel for supporting the Lewis
A novel polysulfone (PSF) mixed matrix membrane blended by polyethylene glycol (5 and 10?wt.%) was synthesized in which the graphene hydroxyl (G-OH) nanoparticles incorporated. Polyethelene glycol (PEG) as an affordable additive provides a proper CO2 affinity. Moreover, the G-OH nanoparticles was enhanced the CO2 permeability in MMMs through Lewis acid- base interaction between electron withdrawing oxygen of −OH and CO2. First, PSF membrane was modified via adding PEG. Obtained results were shown that the CO2 permeability increased significantly from 15.9 Barrer (for neat PSF) to 28.2 Barrer (for PSF/PEG (10?wt%), while a fairly significant increase in CO2/CH4 selectivity (from 12.23 for neat PSF to 12.81 for PSF/PEG (10?wt%) at the press
Keggin-type heteropoly acids are known as active catalysts for oxidative desulfurization of refractory sulfur compounds from fuels. In this work, cesium salts of phosphotungstic acid (HPW) were synthesized based on three different methods: co-precipitation, reversed emulsion, and reversed microemulsion. For reversed microemulsion procedure, the effect of adding order of cesium ion or phosphotungstic acid in the micelle aggregation of sodium dodecyl sulfate (SDS) surfactant was investigated to synthesize different particle sizes of heterogeneous HPW. Obtained products were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and N 2 physical adsorption–des
In this work, blend membranes based on poly(ethylene oxide-b-amide 6), i.e. Pebax 1657, and 30 wt% of dense, rubbery and CO2-philic vinyl acetate/ dibutyl maleate (VAc/DBM) copolymers with different chemical compositions were prepared. Depending on the copolymer composition, glass transition temperature (Tg) of copolymers were measured to be in the range of 7–23 ?C. Copolymer composition dependency of the copolymers' density was also evaluated. Interaction of the various components present in as well as morphology of the blend membranes were investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and field emission scanning electron microscopy (FE-SEM) analyses. The permeability of CO2,
Research subject: In recent years, researchers have proposed various methods for gas separation because of rising greenhouse gases in the atmosphere and causing enormous environmental problems. One of the newest and emerging methods is membrane gas separation. In the last decade, mixed matrix membranes (MMMs) have received much attention due to their ability to successful separation of polar gases from mixtures.Research approach: In this study, a novel two-component mixed matrix membrane was prepared by incorporating the nickel zinc iron oxide nanoparticles into the Pebox polymer matrix. This is owing to combination the unique features of Pebax copolymer such as high mechanical strength and gas permeability, with nanoparticle properties as
This work investigates the performance and structure of polyamide thin film nanocomposite (PA-TFN) membrane incorporated with triethylenetetramine-modified graphene oxide (GO-TETA). The embedment of GO-TETA nanosheets within the structure of PA-TFN membrane was evaluated at different concentrations (0.005, 0.01, 0.03?wt%; in aqueous piperazine (PIP)) through interfacial polymerization (IP). The physicochemical properties of the prepared membrane were investigated by SEM, AFM, water contact angle, and zeta potential as well as ATR-IR spectroscopy. The presence of longer chains of amino groups (in comparison with the directly linked amino ones) among the stacked GO nanosheets was assumed to increase interlayer spacing, resulting in remarkable
Extra-high-performance low-level filler-loaded mixed-matrix membranes (MMMs) were fabricated by embedding a flexible cyclooligomer, calix[4]arene (CA), as a macrocyclic porous filler in two blends of a commercial polyether block amide polymer, Pebax MH 1657. Two kinds of liquid phases, PEG550 (PEG) and [OMIM][PF6] (IL), were separately introduced into the Pebax MH 1657 matrix to prepare blended membranes for enhancing the CO2 permeability and comparing their performance. Afterward, CA as the third generation of supramolecular hosts with high inherent affinity to CO2 was synthesized and incorporated in the polymer blends to fabricate high-performance MMMs. The organic nature, the high compatibility of other applied additives with Pebax MH 16
This study investigated the effect of different surface modifications on the microwave absorption performance of new synthesized MWCNT-Fe3O4 nanohybrid. MWCNT-Fe3O4 nanohybrids were synthesized via a co-precipitation method. For the dispersion of these nanomaterials into the water (as the injected fluid), the surfaces of them were modified. For this purpose, three different materials included 3-AminoPropylTriEthoxySilane (APTES), citric acid (CA), and polyethylene glycol (PEG 6000) were used as the surface modification agents. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray crystallography (XRD), vibrating sample magnetometer (VSM), and field emission scanning electron microscopy (FESEM). Stabil
In this study, Pebax@1657/glycerol/polyethylene glycol 200/iron-nickel oxide quaternary mixed matrix membranes (MMMs) were prepared, to enhance the gas separation permeation of Pebax@1657 copolymer membrane, by utilizing the high miscibility of all the membrane material components and the strong affinity between CO2and glycerol/ethylene glycol200 additives and also with iron-nickel oxide filler. The resultant membranes were examined for CO2/CH4 and CO2/N2gas separation at 35?C and feed pressures of 2-10 bar. These membranes were also characterized by FTIR-ATR, DSC, FE-SEM, XRD and XRF and the tensile test. Incorporation of these additives in the pure Pebax@1657 membrane significantly improved the separation performance ofneat membrane. For
In present study, new visible driven photocatalysts (TiO2/4-CNT/20-BiOBr/10-Bi2S3) with various loading of CNT (2, 4, 6 and 8 wt%), (10, 20, 30 and 40 wt%) and Bi2S3 (5, 10, 15 and 20 wt%) were successfully synthesized and characterized by XRD, FTIR, FESEM, PL, and DRS analysis. The DRS and PL analysis confirmed a redshift of modified TiO2 into a visible light range and the reduction of the recombination rate of electron/hole. The photodegradation results showed the optimum weight percentage of CNT, BiOBr, and Bi2S3 was 4%, 20%, and 10% respectively. Besides, the central composite design (CCD) was applied to model and optimize the photocatalytic activity of nanocatalyst for photodegradation of reactive blue 19 (RB19) and assess the effects
Metal–organic frameworks (MOFs) have attracted considerable attention for selective deep removal of refractory sulfur compounds from fuels. In this work, cobalt-based MOFs (nanocrystals of Co-ZIF-67) were successfully prepared to find a capable adsorbent for removal of dibenzothiophene (DBT) from fuel. This paper revealed the main importance of preparation conditions in adjusting the surface area and pore structure of Co-ZIF-67 crystals for DBT adsorption purposes. Several methods including XRD, SEM, TEM, FTIR, TGA, BET, BJH, and N2 adsorption–desorption were used for characterization of the prepared adsorbents. Screening the adsorbents demonstrated the proper structure and performance of Co-ZIF-67/M nanocrystals synthesized by methanol
This study investigates separation performance of a polymer-IL hybrid membrane comprised of Elvaloy4170 and 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][Tf2N]) ionic liquid. The goal is to incorporate superior features of Elvaloy4170 as a cost-effective commercial polymer with desirable CO2 permeability and mechanical strength, with those of [Emim][Tf2N] such as high affinity to CO2 molecules for fabricating high performance hybrid membranes. Results revealed that the presence of IL within the polymeric matrix leads to simultaneous enhancement of permeability and selectivity values. This is confirmed by the increase in CO2 permeability from 88 to 141 Barrer accompanied with 2.5 fold increase in CO2/CH4 ideal selecti
Thermophysical properties of base ionic liquid (C10H19F6N2P) (IL) and IoNanofluids (INF) containing different contents of (0.05, 0.1, and 0.5 wt%) multiwalled carbon nanotubes (MWCNTs) and Graphene (Gr) were measured experimentally. INF exhibited augmentation in thermal conductivity, viscosity, and heat capacity respect to the base fluid. Maximum thermal conductivity breakthrough was detected at 39%, 48% of MWCNT-IL and 0.5wt% of Gr-IL, respectively. Eventually, the experimental viscosity and thermal conductivity data were fitted with the existing theoretical models. The findings highlighted that the viscosity of MWCNTs-IL and Gr-IL was in unison with particles aggregation effect (Krieger-Dougherty model) and the both INF effective thermal