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    Controlled growth of hollow polyaniline structures: From nanotubes to microspheres

    , Article Polymer (United Kingdom) ; Volume 54, Issue 21 , 2013 , Pages 5586-5594 ; 00323861 (ISSN) Pirhady Tavandashti, N ; Ghorbani, M ; Shojaei, A ; Sharif University of Technology
    2013
    Abstract
    Homogeneous and fairly monosized microspherical structures of polyaniline has been synthesized using a simple soft template method with β-naphthalene sulfonic acid (β-NSA) as both the surfactant and dopant, and ammonium persulfate (APS) as the oxidant at 2-5 C. The morphology of PANI-NSA was successfully controlled from nanotubes to microsphere, by changing the synthesis conditions (i.e. pH, the concentration of surfactant and monomer, and temperature). Some mechanistic aspects of the formation of nanotubes and hollow spheres have been discussed precisely based on SEM, TEM, DLS, FTIR and UV-visible results. Moreover, synthesis was performed under acidic environment to obtain further... 

    Morphology transition control of polyaniline from nanotubes to nanospheres in a soft template method

    , Article Polymer International ; Volume 64, Issue 1 , June , 2015 , Pages 88-95 ; 09598103 (ISSN) Pirhady Tavandashti, N ; Ghorbani, M ; Shojaei, A ; Sharif University of Technology
    John Wiley and Sons Ltd  2015
    Abstract
    A soft template route is reported for the fabrication of polyaniline nanospheres via the oxidative polymerization of aniline in the presence of β-naphthalenesulfonic acid (β-NSA) as both surfactqant and dopant, and ammonium persulfate as oxidant at 2-5°C. Control over the morphology and size of the nanoparticles was achieved by changing the reaction medium via addition of an organic cosolvent (i.e. ethanol or ethylene glycol) and by controlling the concentrations of aniline and β-NSA and the molar ratio of β-NSA to aniline. By this means the size of the β-NSA-aniline micelles and the way that aniline monomer interacts with the micelles were controlled. In fact the lower dielectric constant... 

    Nanodiamond loaded with corrosion inhibitor as efficient nanocarrier to improve anticorrosion behavior of epoxy coating

    , Article Journal of Industrial and Engineering Chemistry ; Volume 83 , 2020 , Pages 153-163 Rahmani, P ; Shojaei, A ; Pirhady Tavandashti, N ; Sharif University of Technology
    Korean Society of Industrial Engineering Chemistry  2020
    Abstract
    In the present study, thermally oxidized nanodiamond (OND) was first modified non-covalently with dodecylamine (DDA) as corrosion inhibitor. In this respect, reactive primary amine of DDA molecule with high isoelectric point (IEP) could interact easily with negative charge carboxylic acid groups of OND. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) proved that OND nanoparticle was successfully functionalized by DDA up to approximately 5 wt% grafting contnet. Both OND and dodecylamine modified OND (DND) were loaded in epoxy (EP)/polyamine hardener matrix at the same concentration of 1 wt% and applied on mild steel substrate. Morphology of EP-DND and... 

    Synthesis and Characterization of Anticorrosive Hybrid Epoxy Coating based on Polyaniline/Nanodiamond Nanostructures

    , M.Sc. Thesis Sharif University of Technology Mohammadkhani, Rahman (Author) ; Shojaei, Akbar (Supervisor) ; Pirhady, Nahid (Co-Advisor)
    Abstract
    One of the ways that corrosion control is presented is the use of coatings that have good properties such as high adhesion, impact resistance, ultraviolet radiation, and so on. They also have other unique properties like anti-corrosion property. To achieve coatings with these advanced properties, they use special properties of nanocomposites. Nanocomposites can add or improve one or more properties to coating properties.In the present study, we tried to first synthesize NanoDiamond/Polyaniline hybrid nanoparticles in different percentages and then use this hybrid in epoxy ester coating. To characterize this hybrid, various analyzes such as FE-SEM, TEM, FT-IR, UV-Visible, TGA and XRD were... 

    Preparation and Characterization of Self-healing Coatings Using Inhibitor Loaded Polymeric Nanocontainers

    , Ph.D. Dissertation Sharif University of Technology Pirhady Tavandashti, Nahid (Author) ; Ghorbani, Mohammad (Supervisor) ; Shojaei, Akbar (Supervisor)
    Abstract
    The aim of this work was to synthesize hollow polyaniline nanostructures to be used as pH responsive nanoreservoirs for corrosion inhibitors in self-healing cotings. First, homogeneous and fairly monosized microspherers of polyaniline with nanosized shell was synthesized using a simple soft template method with β-naphthalene sulfonic acid (β-NSA) as both the surfactant and dopant, and ammonium persulfate (APS) as the oxidant at 2-5◦C. The morphology of PANI-NSA was successfully controlled from nanotubes to microsphere, by changing the synthesis conditions (i.e. pH, the concentration of surfactant and monomer, temperature, etc). Then, the nanostructured hollow PANI microspheres were applied... 

    Synthesis and characterization of polyaniline/nanodiamond hybrid nanostructures with various morphologies to enhance the corrosion protection performance of epoxy coating

    , Article Diamond and Related Materials ; Volume 120 , 2021 ; 09259635 (ISSN) Mohammadkhani, R ; Shojaei, A ; Rahmani, P ; Pirhady Tavandashti, N ; Amouzegar, M ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    In this study, nano-sized diamond particles (ND) were functionalized in two consecutive stages. First, dry thermal oxidation was employed to obtain carboxylated ND. In the next step, carboxylated ND was properly surface modified through wet chemistry to acquire aminated-ND (ND-NH2). Then, polyaniline (PANI) was synthesized in the presence of aminated-ND particles at a broad concentration from 1 wt% to 70 wt% to obtain PANI/ND hybrid nanostructures. The chemical structure, morphology, and thermal stability of nanoparticles were comprehensively characterized by different techniques such as FT-IR, UV–visible, TGA, XRD, FESEM, and TEM. It was observed that the morphology of PANI/ND... 

    PH responsive Ce(III) loaded polyaniline nanofibers for self-healing corrosion protection of AA2024-T3

    , Article Progress in Organic Coatings ; Volume 99 , 2016 , Pages 197-209 ; 03009440 (ISSN) Pirhady Tavandashti, N ; Ghorbani, M ; Shojaei, A ; Gonzalez Garcia, Y ; Terryn, H ; Mol, J. M. C ; Sharif University of Technology
    Elsevier  2016
    Abstract
    Cerium nitrate loaded polyaniline (PANI) nanofibers were synthesized in this work via a chemical route. PANI nanofibers act as a host structure for the corrosion inhibitor, forming a Ce(III)-PANI complex. This complex is pH sensitive, and a change of pH can cause breaking of the complex and releasing of Ce(III). The Ce(III) loaded PANI nanofibers were embedded into epoxy ester coating and the self-healing corrosion protection ability was investigated by Scanning Vibrating Electrode Technique (SVET) and Electrochemical Impedance Spectroscopy (EIS). The results showed that by embedding of Ce(III) loaded PANI nanofibers into the coatings a superior corrosion protection and self-healing... 

    Inhibitor-loaded conducting polymer capsules for active corrosion protection of coating defects

    , Article Corrosion Science ; Volume 112 , 2016 , Pages 138-149 ; 0010938X (ISSN) Pirhady Tavandashti, N ; Ghorbani, M ; Shojaei, A ; Mol, J. M. C ; Terryn, H ; Baert, K ; Gonzalez Garcia, Y ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    This work presents the synthesis of nanostructured hollow polyaniline (PANI) capsules and their application for encapsulation of corrosion inhibitor 2-Mercaptobenzothiazole (MBT). The pH-triggered release of MBT from the capsules was evidenced using UV–vis and Surface Enhanced Raman Spectroscopy (SERS). Incorporation of MBT loaded PANI capsules into epoxy ester coating on AA2024-T3 resulted in a protective system with self-healing ability confirmed by Electrochemical Impedance Spectroscopy (EIS) and Scanning Vibrating Electrode Technique (SVET). The results showed that the incorporation of MBT-loaded PANI capsules into the coating has significantly improved its corrosion protection... 

    Treatment of bakers yeast wastewater with a Biopack system

    , Article Process Biochemistry ; Volume 37, Issue 5 , 2001 , Pages 447-451 ; 13595113 (ISSN) Nahid, P ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
    2001
    Abstract
    The purpose of this study was to investigate the use of a horizontal packed bed bioreactor, named Biopack, to treat high strength wastewater, such as bakers yeast wastewater. The Biopack system (RBCP) is a modified rotating biological contactor and the system was applied for secondary treatment. The RBCP system produced high treatment efficiencies, COD removal was 94.9% when COD was 472 mg/l and surface organic loading = 0.187 kg COD/m2 per day and surface hydraulic loading = 6 l/m2 per day. Variations of surface hydraulic loading from 6 to 11.9 l/m2 per day produced a decrease in COD removal efficiency from 94.9 to 58.6%. Other factors, such as shock load, retention time and rotational... 

    Preparation and Characterization of Inhibitor Loaded Nanodiamond for Anticorrosion Coating

    , M.Sc. Thesis Sharif University of Technology Rahmani, Pooria (Author) ; Shojaei, Akbar (Supervisor) ; Pirhadi, Nahid (Co-Supervisor)
    Abstract
    In recent years, nanodiamond (ND) has been used as reinforcement in polymeric nanocomposites in order to improve mechanical properties, thermal conductivity, etc. The surface of nanodiamond has several functional groups which make it appropriate adsorbent. In this study, nanodiamond was modified with dodecylamine corrosion inhibitor and was utilized (1wt %) in epoxy based nanocomposite. Fourier transform infrared spectroscopy (FTIR) analysis was used to confirm the surface modification of Nanodiamond. In order to estimate the loading amount of corrosion inhibitor, thermogravimetric analysis was investigated. FE-SEM analysis demonstrated nanoparticle dispersibility in epoxy matrix. Regarding... 

    Production of low ester (LM) pectin by de-esterification of high ester (HM) apple pectin

    , Article Scientia Iranica ; Volume 12, Issue 3 , 2005 , Pages 306-310 ; 10263098 (ISSN) Alemzadeh, I ; Saifkordi, A. A ; Kahforooshan, D ; Nahid, P ; Sharif University of Technology
    Sharif University of Technology  2005
    Abstract
    In this paper, LM pectin production from commercial apple pectin by using acid, alkali and ammonia methods in the presence of ethanol was studied. Also, the effect of different parameters such as, temperature, time, acid, alkali and ammonia treatment in LM pectin production were evaluated. In all the experiments, low temperature showed a better influence from a recovery, purity and low de-polymerization viewpoint. Optimum conditions in the acid method reached at pH = 2, t = 17 hrs and T = 30°C, in the alkaline method reached at pH = 11, t = 3 hrs and T = 5°C and in the ammonia method reached at 2 N ammonia and T = 5°C, were determined. © Sharif University of Technology  

    Synthesis and Characterization of a Copper Catalyst for Low Temperature Water –Gas Shift Reaction

    , M.Sc. Thesis Sharif University of Technology Rafiee Renani, Mansoureh (Author) ; Khorasheh, Farhad (Supervisor) ; Khandan, Nahid (Co-Advisor)
    Abstract
    Water Gas Shift (WGS) reaction is an old reaction in which syngas is used for producing Hydrogen. At the present time, the major application of this reaction is in fuel cells, since the necessary Hydrogen for these cells is provided by this reaction.
    The present study investigate the influence of different preparation methods on properties of Cu-ZnO/Al2O3 catalyst for water gas shift (WGS) reaction, which is now known as the Commercial catalyst for low temperature WGS, and its influence on performance of Cu-ZnO/Al2O3 catalyst to derive an optimal Cu-ZnO/Al2O3 catalyst for water gas shift (WGS) reaction. Cu-ZnO/Al2O3 catalysts was synthesized by CP, DP, DP-Ultra, IWI , CP-Urea, and... 

    Alkaline protease production by immobilized cells using B. licheniformis

    , Article Scientia Iranica ; Volume 20, Issue 3 , 2013 , Pages 607-610 ; 10263098 (ISSN) Maghsoodi, V ; Kazemi, A ; Nahid, P ; Yaghmaei, S ; Sabzevari, M. A ; Sharif University of Technology
    2013
    Abstract
    In recent years there has been potential increase in the use of alkaline protease as industrial catalysts. Many major industrial and commercial applications, such as food and textile industries, and medical diagnoses, are highly dependent on the protease enzyme. In the cell immobilization technique, the free movement of microorganisms is restricted in the process, and a continuous system of fermentation can be used. In the present work, this technique has been used for alkaline protease production using different carriers, such as chitosan, corn cob and corn tassel. Enzyme activity before immobilization (72 h) was 78.3 U/ml. Corn cob, with 65% immobilization capacity and the highest enzyme... 

    Investigation of Effective Parameters on Membrane Fouling in Membrane Bioreactors

    , M.Sc. Thesis Sharif University of Technology Khorasanizadeh, Mohaddeseh (Author) ; Kariminia, Hamid Reza (Supervisor) ; Nahid, Parvin (Co-Advisor)
    Abstract
    Critical flux is an important parameter in membrane bioreactors, which studying it can give a better understanding of treatment by these bioreactors and make utilizing them easier. In this study, the effect of some sludge properties like it’s concentration, sludge volum index, concentration of protein and carbohydrate in EPS and SMP and the effect of some operating conditions like aeration flow rate and rest mode on critical flux in a submerged membrane bioreactor are investigated. In addition to comparison of TMP-t figures drived from flux step experiment, the hystersis figures are also compared. Finally, two long term experiments at two sub critical fluxes are done in order to study the... 

    Kinetics Study and Determining an Optimum Reactor Condition for Dimethyl-ether Synthesis by Dehydration of Methanol over Nano-Crystalline γ-Al2O3

    , M.Sc. Thesis Sharif University of Technology Alamolhoda, Sarah (Author) ; Kazemeini , Mohammad (Supervisor) ; Khorashe, Farhad (Supervisor) ; Khandan, Nahid (Supervisor)
    Abstract
    Dimethyl Ether (DME) is a pure and economic fuel which can be used as a suitable alternative for diesel fuels. Two processes are traditionally used for DME synthesis: producing methanol from synthesis gas and then dehydrating it to DME (direct process), and converting methanol into DME in a catalytic dehydration reactor over a solid-acid catalyst (indirect process), in which the indirect process seems to have economical advantage. In this research, the γ-Al2O3 catalyst was synthesized through precipitation process and then characterized by powder X-ray diffraction (XRD) and porosimetry analysis. Afterwards this catalyst was utilized in methanol dehydration reaction in a slurry reactor. Next,... 

    Production of glucoamylase by aspergillus niger under solid state fermentation

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 25, Issue 1 , 2012 , Pages 1-7 ; 1728-144X (ISSN) Nahid, P ; Vossoughi, M ; Roostaazad, R ; Ahmadi, M ; Zarrabi, A ; Hosseini, S. M ; Sharif University of Technology
    2012
    Abstract
    In this study, Glucoamylase production by Aspergillus niger was investigated under solid state fermentation using low cost by-products of agricultural processes as substrate. Highest enzyme production was observed when a combination of wheat bran (WB) and corn flour (CF) was used as compared to WB+ rice bran, WB+ rice flour and WB alone. Several compositions of corn flours were experimented. The best combination of WB in addition of 10% corn flour resulted maximum enzyme activities. Study of the fermentations in flasks revealed 373.3 IU/gds and 41.4 g/l for the enzyme activity and protein concentration respectively under conditions of 30± 1°C, pH 4.7 and time 96 h. Optimum conditions... 

    PH-responsive nanostructured polyaniline capsules for self-healing corrosion protection: the influence of capsule concentration

    , Article Scientia Iranica ; Volume 24, Issue 6 , 2017 , Pages 3512-3520 ; 10263098 (ISSN) Tavandashti, N. P ; Ghorbani, M ; Shojaei, A ; Mol, J. M. C ; Terryn, H ; Gonzalez Garcia, Y ; Sharif University of Technology
    2017
    Abstract
    Nanostructured hollow polyaniline (PANI) capsules are good candidates for encapsulation of corrosion inhibitors and pH-responsive release when incorporated into organic coatings. In previous studies, the corrosion protection performance of PANI capsules, containing organic inhibitor 2-Mercaptobenzothiazole (MBT), was demonstrated. The present work studies the influence of capsule concentrations (i.e., 0.3, 1, and 2 wt%) on the corrosion protection properties of the coating system. Anti-corrosion properties of different coatings were compared by means of Electrochemical Impedance Spectroscopy (EIS) and Scanning Vibrating Electrode Technique (SVET). MBT loaded PANI capsules in epoxy ester... 

    Investigation of the Governing Liquid-Liquid Interactions at the Oil-Brine Interface in Low-Salinity Waterflooding using Molecular Dynamics Simulations

    , M.Sc. Thesis Sharif University of Technology Seif, Arya (Author) ; Mahani, Hassan (Supervisor) ; Ayatollahi, Shahaboddin (Supervisor) ; Pourkhiabani, Nahid (Co-Supervisor) ; Koleini, Mohammad Mehdi (Co-Supervisor)
    Abstract
    The characteristics of the brine-crude oil interface in hydrocarbon reservoirs are very important, especially during water-based enhanced oil recovery (EOR) operations such as low-salinity waterflooding. At the interface of the two aforementioned fluids, the interaction mechanisms between the molecules of these two non-miscible fluids would affect capillary forces hence the efficiency of the EOR method. However, based on the published literature, there are still many open questions and uncertainties about the interaction of oil and brine molecules at the interface and their roles in the interfacial tension (IFT) changes for different oil and brine compositions. In this regard, molecular... 

    Molecular Dynamics Simulation of Hydrogen Diffusion into Brine: Implications for Underground Hydrogen Storage

    , M.Sc. Thesis Sharif University of Technology Kalati, Saba (Author) ; Ayatollahi, Shahaboddin (Supervisor) ; Mahani, Hassan (Supervisor) ; Pourkhiabani, Nahid (Co-Supervisor) ; Esmaeilbeig, Mohammad Amin (Co-Supervisor)
    Abstract
    The high consumption of worldwide fossil energy and its detrimental effects on the environment and climate have prompted a transition toward renewable energy sources. The availability of renewable energy sources depends on weather and seasonal changes; therefore, an imbalance between supply and demand would be unavoidable. Hydrogen storage as an energy carrier, can fulfill this energy mismatch. Storing hydrogen in underground formations, such as aquifers, has been the subject of extensive research recently. In these storage reservoirs, hydrogen contacts the resident brine which will be lost through the dissolution-diffusion mechanism. Therefore, successful design of these storages requires... 

    Investigation of Ionic Diffusion and Mixing Phenomena in Polymer-Enhanced Low-Salinity Waterflooding Using Molecular Dynamics Simulation

    , M.Sc. Thesis Sharif University of Technology Abdolmaleki, Amir Hossein (Author) ; Ayatollahi, Shahaboddin (Supervisor) ; Mahani, Hassan (Supervisor) ; Esmaeilbeig, Mohammad Amin (Co-Supervisor) ; Pourkhiabani, Nahid (Co-Supervisor)
    Abstract
    Various studies have confirmed that water salinity and its composition significantly affect the efficiency of the waterflooding process. Field-scale operation of low-salinity water injection has been proven to be a cost-effective enhanced oil recovery (EOR) method which is also compatible with the environmental regulations. Although this method has satisfactory results, it faces some challenges, such as in-situ mixing of the injection low-salinity water with the saline water in the host reservoir. The salinity of the injected water increases, as it contacts the high-salinity reservoir brine in the pores. This phenomenon significantly impairs the efficiency of this technique, and increases...