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    Synthesis of nano particles of LTA zeolite by means of microemulsion technique

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 30, Issue 2 , 2011 , Pages 1-8 ; 10219986 (ISSN) Esmaeili, N ; Kazemian, H ; Bastani, D ; Sharif University of Technology
    2011
    Abstract
    This mini review article, intends to provide the essential information about microemulsion technique as a reliable approach toward the synthesis of zeolitic nano crystallites. The strategy discussed here provides a unique, effective, and potentially general methodology to the preparation of uniform and high purity nano crystallites of template-free zeolitic materials including LTA, faujasite type and other zeolitic-like materials (i.e. zeotype materials). Microemulsion is a reliable approach for controlled synthesis of uniform nano sized zeolitic particulates. On the other hand, the microwave assisted microemulsion technique has the advantages of short reaction time, producing smaller and... 

    Microemulsion synthesis of nanoparticle PZT powder

    , Article AIP Conference Proceedings, 24 October 2010 through 27 October 2010 ; Volume 1315 , 2010 , Pages 265-270 ; 0094243X (ISSN) ; 9780735408715 (ISBN) Amiriyan, M ; Nemati, Z. A ; Rahmanifar, M. S ; Ramesh, S ; Meenaloshini, S ; Tolouei, R ; Sharif University of Technology
    Abstract
    Nanocrystalline lead zirconate titanate (PZT) powders have been synthesized using microemulsion processing route. Microemulsion is one of the major processing techniques to synthesize a nanosize, homogenous, and almost agglomerate free ceramic powders. The ternary microemulsion system is consisted of cyclohexane as the oil phase, Triton X100 as the nonionic surfactant phase, and an aqueous phase containing 0.619MPb 2+, 0.325MZr 4+, and 0.3MTi 4+, representing a Pb 2+: Zr 4+: Ti 4+ molar ratio of 1:0.52:0.48. The ratio of these cations has been adjusted using Inductively Coupled Plasma (ICP) technique. After coprecipitation of metallic hydroxides by adding ammonia solution in microemulsion... 

    Theoretical and Experimental Investigation of Nanoparticle Formation Via Microemulsion Method

    , Ph.D. Dissertation Sharif University of Technology Vafa, Ehsan (Author) ; Shahrokhi, Mohammad (Supervisor) ; Molaei Dehkordi, Asghar (Supervisor)
    Abstract
    In this work, nanoparticle production via microemulsion method has been investigated from theoretical and experimental points of view. Population balance approach has been used to model nanoparticle formation in an inverse microemulsion system. The study of nanoparticle formation in the inverse microemulsion system of Marlipal O13/40-cyclohexane-water reveals that in low reactants concentrations, the coagulation phenomenon has an important effect on the formation of particles. In this regard, the population balance equations has been developed to consider the coagulation phenomenon in the inverse microemulsion system. The kernel of coagulation has been calculated based on attractive and... 

    Microemulsion Synthesize of Fe3O4/TiO2 Core-Shell Nanoparticles

    , M.Sc. Thesis Sharif University of Technology Sonbolestan, Hosein (Author) ; Madaah Hoseini, Hamid Reza (Supervisor)
    Abstract
    In this study magnetite nanoparticles were synthesized by microemulsion and were coated with TiO2 by a precipitation technique. The synthesize process were done under fixed molar ratio of various constituents of microemulsion and molar ratio of water to oil. Results of X-ray diffraction spectroscopy (XRD) showed that the uncoated nanoparticles were consisted of magnetite as the major phase and no other detectable phases such as pure iron or hematite were found. Field emission scanning electron microscopy (FE-SEM) results showed that the synthesized nanoparticles small size and narrow particle size distribution. For TiO2 coating process the effect of TBOT concentration, water concentration,... 

    Population balance modeling of barium sulfate nanoparticle synthesis via inverse microemulsion including coagulation effect

    , Article Industrial and Engineering Chemistry Research ; Vol. 53, issue. 32 , 2014 , Pages 12705-12719 ; ISSN: 08885885 Vafa, E ; Shahrokhi, M ; Molaei Dehkordi, A ; Sharif University of Technology
    Abstract
    A deterministic model based on the discrete population balance equation (PBE) is used to examine the precipitation of barium sulfate nanoparticles in nonionic inverse microemulsion systems. It is shown that coagulation can have a significant effect at low initial reactants concentration. The simulation results show that a bimodal particle size distribution (PSD) observed in experimental analysis reported in the literature cannot be predicted by neglecting the coagulation effect. A coagulation kernel is proposed that takes into account the effect of interparticle forces through the Fuchs' stability ratio. The effect of electrolyte concentration on the surfactant headgroup area is also... 

    A novel approach for preparation of CL-20 nanoparticles by microemulsion method

    , Article Journal of Molecular Liquids ; Vol. 193, issue , May , 2014 , pp. 83-86 Bayat, Y ; Zarandi, M ; Zarei, M. A ; Soleyman, R ; Zeynali, V ; Sharif University of Technology
    Abstract
    2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) as one of the high energy cage nitramines has been used in various propellants and explosive formulations. The performance of energetic materials depends on its particle size and shape. Therefore, in this research, microemulsion method has been applied for the preparation of CL-20 nanoparticles via oil in water (O/W) microemulsions. The optimized formulation contains water 45%, n-butyl acetate 20.5%, sodium dodecyl sulfate (SDS, as anionic surfactant) 6.5% and 2-propanol (as co-surfactant) 26.5%. CL-20 nanoparticles that were obtained by microemulsion method are spherical with an average diameter of 25 nm, based on TEM image.... 

    Effect of iron oxide and silica doping on microstructure, bandgap and photocatalytic properties of titania by water-in-oil microemulsion technique

    , Article Transactions of the Indian Ceramic Society ; Volume 70, Issue 4 , Jan , 2011 , Pages 227-232 ; 0371750X (ISSN) Karbassi, M ; Nemati, A ; Zari, M. H ; Ahadi, K ; Sharif University of Technology
    2011
    Abstract
    The microemulsion method was successfully used to prepare a series of TiO2, Fe oxide and SiO2 doped TiO2 nanoparticles at Fe/Ti atomic ratio of 10% and Si/Ti atomic ratio of 15%. The molar ratio of water to surfactant (W0) was 2. The samples were calcinated at 350°C. The structural features of TiO2, Fe oxide and SiO 2-TiO2 were investigated by XRD, UV-Visible spectroscopy, SEM and TEM. XRD data verified the formation of typical characteristic anatase form in all the prepared Fe and SiO2-doped TiO2 samples. In comparison with the pure TiO2, Fe oxide and SiO 2-TiO2 samples were relatively large in particle size, indicating that doping with Fe oxide and SiO2 can help in increasing the particle... 

    Enzymatically crosslinked hyaluronic acid microgels as a vehicle for sustained delivery of cationic proteins

    , Article European Polymer Journal ; Volume 115 , 2019 , Pages 234-243 ; 00143057 (ISSN) Jooybar, E ; Abdekhodaie, M. J ; Mousavi, A ; Zoetebier, B ; Dijkstra, P. J ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    In this study, a novel biodegradable hyaluronic acid (HA) based microgel were prepared via enzymatic crosslinking of tyramine conjugated HA (HA-TA) in an inverse microemulsion. HA-TA microdroplets were crosslinked within a few seconds in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H 2 O 2 ). The high water content of the polymeric network and the inherent negative charge of the HA-TA microgels provided a suitable platform for encapsulation of cationic proteins like lysozyme and TGF-β1 growth factor. The results demonstrated that lysozyme was released, after an initial burst release, in a suitable sustained manner over a period of four weeks. Both diffusion and... 

    , M.Sc. Thesis Sharif University of Technology Rahmani, Atefeh (Author) ; Gholami, Mohammad Reza (Supervisor)
    Abstract
    Nanosized CdS coupled TiO2 nanocrystals were prepared by a microemulsion-mediated Hydrothermal method at relatively low temperatures. Modification of this nanocomposite with Tyrosine,Phenylalanine,Glysine and Glutamate ,especially Tyrosine resulted in enhanced photocatalytic degradation rate of Nitrobenzene( NB ) compared to using CdS-TiO2 under visible light irradiation. The prepared samples were characterized by BET,SEM, XRD, UV–Vis spectroscopy ,FTIR .It was found which have high surface area about 470 m2 g−1 and mesoporous character with the average pore diameter of 2.8 nm.The results showed this nanocomposite consisted of uniform anatase TiO2 with highly dispersed cubic phase CdS... 

    Synthesis of Silver Based Nanocomposite

    , M.Sc. Thesis Sharif University of Technology Jelvani Esfahani, Samaneh (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    Recently, conductive nanocomposites have found great deals of attentions due to their vast applications in different fields. According to the definition of nanocomposite, the filler component should be in the range of 10-100 nm. In this study, silver nanoparticles was used as filler with 4 nm size and synthesized by microemulsion method that is known as the best approach for fabricating silver nanoparticles with small sizes, narrow size distribution and high stability.
    Copoly (ortho-phenylenediamine/dopamine) was used as matrix component. Ortho-phenylenediamine is one of the conductive polymers that was used less than other conductive polymers such as polyaniline in this research area.... 

    Preparation and Properties of PZT-PMN Ceramics using nano PZT Particles Obtained from Microemulsion Method

    , M.Sc. Thesis Sharif University of Technology Amiriyan, Mahdi (Author) ; Nemati, Ali (Supervisor) ; Rahmanifar, Mohammad Safi (Supervisor)
    Abstract
    Microemulsion is one of the major processing techniques to synthesize a nano, homogeneous, and almost agglomerate-free powders. Any kind of oxide ceramics such as piezoelectric ceramics can be synthesis via this method in nano scale without the formation of any intermediate phase. In this study, Lead zirconate titanate (PZT) powders with composition near the morphotropic phase boundary (MPB) have been synthesized via a microemulsion processing route. This emulsion system is a thermodynamically stable mixture of oil (cyclohexane), nonionic surfactant (Triton X100), and an aqueous solution containing specific amount of Pb2+, Zr4+ and Ti4+. The ratio of these ions was adjusted with using ICP.... 

    Laboratory Investigation of Rock Wettability and Interfacial Tension Effects on Relative Permeability, a Quantitative Study

    , M.Sc. Thesis Sharif University of Technology Yassin, Mahmoud Reza (Author) ; Taghikhani, Vahid (Supervisor) ; Ayatollahi, Shahab (Co-Advisor) ; Rostami, Behzad (Co-Advisor)
    Abstract
    About 20% of total oil in the world is reserved in fractured reservoirs and there is also more than 60% of remained oil in the world in these reservoirs. But increasing recovery factor and production from this type of reservoirs was not very successful. After water flooding process most of the oil remains in the reservoir. The amount of remained oil is much more specially in fractured reservoirs. Surfactant flooding in one of the well-known enhanced oil recovery methods for reduction of interfacial tension between fluids to decrease capillary forces that cause less oil trapping and higher oil recovery. But a comprehensive and accurate understanding of the mechanism of this process and... 

    Synthesis and Characterization of Superparamagnetic Iron Oxide Nanoparticles Via Microemulsion (Reverse Micelle) Method as MRI Contrast Agents

    , M.Sc. Thesis Sharif University of Technology Pelaschi, Mohammad Ali (Author) ; Madah Hosseini, Hamid Reza (Supervisor)
    Abstract
    Iron oxide nanoparticles were synthesized using microemulsion technique as MRI contrast agents. Utilization of nanoparticles for biological applications and in this case as MRI contrast agents needs particles to be of small size and also narrow size distribution. For this aim, the effect of several parameters on size and size distribution has been studied. These parameters include water/surfactant ratio, precursor’s concentration and amount of polymer employed to improve nanoparticles colloidal stability. XRD, FE-SEM and TEM results reveal that the synthesized nanoparticles had small size (about 10 nm iron oxide core and 20 nm overall diameter) and possessed narrow size distribution (15-21... 

    Microscopic Investigation of Asphaltene Precipitation during Water flooding Process at Laboratory Condition

    , M.Sc. Thesis Sharif University of Technology Arastuian, Nahid (Author) ; Ayatollahi, Shahaboddin (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor)
    Abstract
    The study of low-salinity water flooding or smart water flooding as secondary or tertiary oil recovery methods started in 1960 and many researchers have studied the effect of ions types on asphaltene precipitation/deposition during the injecting water into the oil reservoirs. To reduce the asphaltene challenges, one needs to properly investigate this phenomenon and better understanding of the cause of precipitation. It is already known that the amount of asphaltene deposition can be reduced by controlling the deposition criteria. For example, water microemulsion in the oil phase would cause the asphaltenes to be adsorbed on the water oil interface by hydrogen bonds due to heteroatom... 

    Interfacial tension and wettability change phenomena during alkali-surfactant interactions with acidic heavy crude oil

    , Article Energy and Fuels ; Vol. 29, issue. 2 , January , 2015 , p. 649-658 ; ISSN: 08870624 Dehghan, A. A ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
    Abstract
    In this work, a newly formulated sulfonate-based surfactant and two other commercial sulfate-based surfactants with the capability of tolerating harsh underground reservoir conditions, such as high-saline formation water and high temperature, were prepared. Sodium metaborate as an effective alkali compound was also used to provide alkali-surfactant combination. Interfacial tension (IFT) measurements as well as wettability examinations for different salinities and mixture conditions were performed for an extended range of the chemical concentrations. The wettability tests including both contact angle measurements and Amott cell tests were performed on saturated Berea sandstone plug samples... 

    Prediction of Surfactant Retention in Porous Media: A Robust Modeling Approach

    , Article Journal of Dispersion Science and Technology ; Vol. 35, issue. 10 , Sep , 2014 , p. 1407-1418 Yassin, M. R ; Arabloo, M ; Shokrollahi, A ; Mohammadi, A. H ; Sharif University of Technology
    Abstract
    Demands for hydrocarbon production have been increasing in recent decades. As a tertiary production processes, chemical flooding is one of the effective technologies to increase oil recovery of hydrocarbon reservoirs. Retention of surfactants is one of the key parameters affecting the performance and economy of a chemical flooding process. The main parameters contribute to surfactant retention are mineralogy of rock, surfactant structure, pH, salinity, acidity of the oil, microemulsion viscosity, co-solvent concentration, and mobility. Despite various theoretical studies carried out so far, a comprehensive and reliable predictive model for surfactant retention is still found lacking. In this... 

    Interfacial tension and wettability change phenomena during alkali-surfactant interactions with acidic heavy crude oil

    , Article Energy and Fuels ; Volume 29, Issue 2 , 2015 , Pages 649-658 ; 08870624 (ISSN) Dehghan, A. A ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
    American Chemical Society  2015
    Abstract
    In this work, a newly formulated sulfonate-based surfactant and two other commercial sulfate-based surfactants with the capability of tolerating harsh underground reservoir conditions, such as high-saline formation water and high temperature, were prepared. Sodium metaborate as an effective alkali compound was also used to provide alkali-surfactant combination. Interfacial tension (IFT) measurements as well as wettability examinations for different salinities and mixture conditions were performed for an extended range of the chemical concentrations. The wettability tests including both contact angle measurements and Amott cell tests were performed on saturated Berea sandstone plug samples... 

    Anticorrosion properties of smart coating based on polyaniline nanoparticles/epoxy-ester system

    , Article Progress in Organic Coatings ; Volume 75, Issue 4 , 2012 , Pages 502-508 ; 03009440 (ISSN) Arefinia, R ; Shojaei, A ; Shariatpanahi, H ; Neshati, J ; Sharif University of Technology
    2012
    Abstract
    In this study, the anticorrosive effect of dodecylbenzenesulfonicacid-doped polyaniline nanoparticles [n-PANI (DBSA)] as a conductive polymer was investigated using electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) techniques. Initially, the n-PANI (DBSA) were successfully synthesized via inverse microemulsion polymerization leading to the spherical nanoparticles with an average diameter less than 30 nm. Two coating systems including 1 wt% n-PANI(DBSA) blended epoxy ester (n-PANI(DBSA)/EPE) and neat epoxy ester (EPE) were coated on the carbon steal substrate. The anticorrosion performance of the prepared coatings was studied using EIS measurement in 3.5%... 

    Experimental investigation on thermal conductivity of water based nickel ferrite nanofluids

    , Article Advanced Powder Technology ; Volume 26, Issue 6 , November , 2015 , Pages 1529-1536 ; 09218831 (ISSN) Karimi, A ; Sadatlu, M. A. A ; Saberi, B ; Shariatmadar, H ; Ashjaee, M ; Sharif University of Technology
    Elsevier  2015
    Abstract
    Experimental investigations are performed in order to determine the thermal conductivity of NiFe2O4 nanoparticles dispersed in deionized water. The magnetic nanoparticles are synthesized using a microemulsion method. The X-ray diffraction (XRD), transmission electronic microscopy (TEM), and vibration sample magnetometer (VSM) are used to characterize the structure, the size and the magnetic properties of the nanoparticles. The VSM results disclose that the NiFe2O4 nanoparticles are ferromagnetic at room temperature. Experimental measurements on thermal conductivity of the prepared nanofluids are conducted at different volume concentrations between 0% and 2% and in the temperature range of... 

    Synthesis and characterization of novel 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane based nanopolymer-bonded explosives by microemulsion

    , Article Journal of Molecular Liquids ; Volume 206 , June , 2015 , Pages 190-194 ; 01677322 (ISSN) Bayat, Y ; Soleyman, R ; Zarandi, M ; Sharif University of Technology
    Elsevier  2015
    Abstract
    2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane (CL-20)-based polymer/plastic bonded explosives are used in propellant formulation. It can be predicted that CL-20-based nano-polymer/plastic bonded explosives are able to have reduced composite sensitivity and superior mechanical strength. In the current study, we have prepared two kinds of CL-20-based nano-polymer/plastic bonded explosives with ethylene-vinyl acetate copolymer and glycidyl azide polymer via the microemulsion method. Several visual techniques such as SEM/AFM/TEM techniques have been utilized for complete characterization of CL-20-based...