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nanocomposites
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Synthesis and Characterization of PVDF Magnetic Nanocomposite
, M.Sc. Thesis Sharif University of Technology ; Forounchi, Massoud (Supervisor)
Abstract
PVDF (polyvinylidene fluoride) magnetic nanocomposite films were prepared by solution casting using two types of nanomagnetic particles: (i) magnetic nanoparticles synthesized by using an alkaline solution of mixed ferrous/ferric salts along with oleic acid as a coating agent at 70˚C; (ii) Fe3O4 nanoparticles prepared by hydrolysis of aqueous solution of ferrous/ferric salts with potassium hydroxide at room temprature. Scanning electron microscopy (SEM) showed that the PVDF magnetic nanocomposite had a porous structure with Fe3O4 nanoparticles dispersed inside the porous polymer matrix. The presence of crystalline magnetite within the polymer matrix was confirmed by X-Ray diffraction method...
Characterisation and Preparation of Chitosan-nano Diamond Nanocomposite
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor)
Abstract
Chitosan is a biocompatible and biopolymer with unique characteristics. Nanodiamonds that are basically carbon based nanoparticle have excellent mechanical, thermal stability biocompatibility bahviors. Combination of these two materials helps to the advantage of all the desirable features of both material and compensate low mechanical properties and strength of chitosan. In this study, we examine the composition of different percentages of nanodiamonds in chitosan and effect of modification on properties of the nanocomposites. The thermal behaviour, swelling behaviour and water contact angle of different nanocomposites were analyzed. Finally, to determine the distribution of the...
Deposition of TiO2/SiO2 Nanocomposite on Cotton Textile by Sol- Gel Method
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
The synthesis and usage of nanoscaled TiO2 accompanied by the photocatalytic activity were experimented through a systematic research. The synthesis was based on the sol-gel method at low temperatures and atmospheric pressure. In recent years, many endeavors have been made so as to enhance the efficiency of TiO2 photocatalytic activity. The studies show that the inclusion of SiO2 into the TiO2 can give rise to the photocatalytic activity relevant to the derived composite Nanoparticles with regard to the pure TiO2. In this study, the production of TiO2-SiO2 Nanocomposite layers was proceeded via the sol method and the effect of SiO2 increasing and its amount in the primary solution on the...
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Electrodeposition of composite coatings containing nano particles is very important because this technique is simple and economic. In this research, in order to produce a coating with high hardness and wear resistance, Ni-Co/WC nano composite was co-deposited. Watt’s based bath containing cobalt and tungsten carbide was used and parameters such as preparation of solution, concentration of ingredients and current density were controlled and adjusted. Surface morphology, microstructure and mechanical properties of coatings were studied by SEM and AFM microscopes. Mechanism of electrodeposition was investigated by cyclic voltametry, cronoamperometry and cronopotentiometry techniques and...
Effects of post-annealing on the microstructure and mechanical properties of friction stir processed Al–Mg–TiO2 nanocomposites [electronic resource]
, Article Journal of Materials & Design ; November 2014, Volume 63, Pages 30–41 ; Simchi, A. (Abdolreza) ; Kokabi, A. H ; Gerlich, A. P ; Nosko, M ; Sharif University of Technology
Abstract
Aluminum matrix nanocomposites were fabricated via friction stir processing of an Al–Mg alloy with pre-inserted TiO2 nanoparticles at different volume fractions of 3%, 5% and 6%. The nanocomposites were annealed at 300–500 °C for 1–5 h in air to study the effect of annealing on the microstructural changes and mechanical properties. Microstructural studies by scanning and transmission electron microscopy showed that new phases were formed during friction stir processing due to chemical reactions at the interface of TiO2 with the aluminum matrix alloy. Reactive annealing completed the solid-state reactions, which led to a significant improvement in the ductility of the nanocomposites (more...
Microstructure and texture development during friction stir processing of Al–Mg alloy sheets with TiO2 nanoparticles [electronic resource]
, Article Materials Science and Engineering: A ; 27 May 2014, Volume 605, Pages 108–118 ; Simchi, A. (Abdolreza) ; Kokabi, A. H ; Nosko, M ; Simancik, F ; Svec, P ; Sharif University of Technology
Abstract
Aluminum matrix nanocomposites were fabricated by friction stir processing of Al–Mg alloy sheets with pre-placed TiO2 nanoparticles at a concentration of 2 to 6 vol%. Microstructural studies showed that solid state reactions between the metal matrix and TiO2 particles caused in situ formation of MgO and Al3Ti nanophases with an average size ~50 nm. These nanophases were homogenously distributed in an ultra-fine grain structure (0.2–2 µm) of the base metal. The results of pole figures evaluation obtained by electron back scattered diffraction studies revealed that the random orientation of initial annealed sheet was changed to components near to shear and silver texture in the friction stir...
Effect of nanoparticle content on the microstructural and mechanical properties of nano-SiC dispersed bulk ultrafine-grained Cu matrix composites [electronic resource]
, Article Journal of Materials & Design ; December 2013, Volume 52, Pages 881–887 ; Salahi, E ; Alikhani Hesari, F ; Kim, H. S ; Simchi, A. (Abdolreza) ; Sharif University of Technology
Abstract
In this study, the microstructural and mechanical features of monolithic pure Cu and Cu matrix nanocomposites reinforced with three different fractions (2, 4, and 6 vol%) of SiC nanoparticles (n-SiC) fabricated via a combination of high energy mechanical milling and hot pressing techniques were investigated. The fabricated composites exhibited homogeneous distribution of the n-SiC with few porosities. It was found that the grain refinement, the planar features within the grains, and the lattice strains increase with increase in the n-SiC content. The yield and compressive strengths of the nanocomposites were significantly improved with increases in the n-SiC content up to 4 vol%; then they...
Microstructural development and mechanical properties of nanostructured copper reinforced with SiC nanoparticles [electronic resource]
, Article Journal of Materials Science and Engineering: A (Elsevier) ; 15 April 2013, Volume 568, Pages 33–39 ; Salahi, E ; Hesari, F. A ; Yoon, E.Y ; Kim, H.S ; Simchi, A. (Abdolreza) ; Sharif University of Technnology
Abstract
Nanostructured Cu and Cu-2 vol% SiC nanocomposite were produced by high energy mechanical milling and hot pressing technique. Microstructure development during fabrication process was investigated by X-ray diffraction, scanning electron microscope, scanning transmission electron microscope, and electron backscatter diffraction techniques. The results showed that the microstructure of copper and copper-based nanocomposite composed of a mixture of equiaxed nanograins with bimodal and non-random misorientation distribution. The presence of SiC nanoparticles refined the grain structure of the copper matrix while the fraction of low angle grain boundaries was increased. Evaluation of mechanical...
Nano sized ZnO composites: Preparation, characterization and application as photocatalysts for degradation of AB92 azo dye
, Article Materials Science in Semiconductor Processing ; Volume 21 , May , 2014 , Pages 167–179 ; Tasviri, M. (Mahboubeh) ; Rahimic, E. (Esmail) ; Gholamia, M. R. (Mohammad Reza) ; Sharif University of Technology
Abstract
ZnO and Mordenite zeolite (MOR) nanoparticles were prepared by precipitation process using ultrasonic irradiation and hydrothermal method, respectively. Supported ZnO catalysts were prepared and the effect of different supports on the photocatalytic activity of ZnO nanoparticles was investigated. All prepared samples were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform-Infra Red Spectroscopy (FTIR), UV–vis spectroscopy (UV–vis) and BET surface area technique. The photocatalytic activity of the synthesized catalysts was elucidated using the photo-oxidation of Acid Blue 92 (AB92) as a hazardous pollutant under UV light. The effect of different...
Adsorption characteristics of malachite green dye onto novel kappa-carrageenan-g-polyacrylic acid/TiO2-NH2 hydrogel nanocomposite
, Article Journal of the Iranian Chemical Society ; Volume 11, Issue 4 , August 2014 , Pages 1057-1065 ; Doulabi, M ; Doroudian, M ; Sharif University of Technology
Abstract
Batch adsorption experiments were carried out for the removal of malachite green (MG) cationic dye from aqueous solution using novel hydrogel nanocomposite that was prepared by graft copolymerization of acrylic acid (AA) onto kappa-carrageenan (κC) biopolymer in the presence of a crosslinking agent, a free radical initiator and aminosilica-functionalized TiO2 nanoparticles (κC-g-PAA/TiO2-NH2). The factors influencing adsorption capacity of the adsorbents such as initial pH value (pH0) of the dye solutions, TiO2-NH2 content (wt%), initial concentration of the dye, amount of adsorbents, and temperature were investigated. The adsorption capacity of hydrogel nanocomposite for MG was compared...
MWCNT/WO3 nanocomposite photoanode for visible light induced water splitting
, Article Journal of Solid State Chemistry ; Volume 204 , 2013 , Pages 341-347 ; 00224596 (ISSN) ; Reyhani, A ; Naseri, N ; Moshfegh, A. Z ; Sharif University of Technology
2013
Abstract
The Multi-walled carbon nanotube (MWCNT)/WO3 nanocomposite thin films with different MWCNT's weight percentages were prepared by sol-gel method as visible light induced photoanode in water splitting reaction. Weight percentage of MWCNT in the all nanocomposite thin films was confirmed by TGA/DSC analysis. According to XPS analysis, oxygenated groups at the surface of the MWCNT and stoichiometric formation of WO3 thin films were determined, while the crystalline structure of the nanocomposite samples was studied by XRD indicating (0 0 2) peak of MWCNT in the monoclinic phase of WO3. The influence of different weight percentage (wt%) of MWCNT on WO3 photoactivity showed that the electron...
Shearing and mixing effects on synthesis and properties of organoclay/polyester nanocomposites
, Article Rheologica Acta ; Volume 51, Issue 11-12 , November , 2012 , Pages 1007-1019 ; 00354511 (ISSN) ; Samadfam, M ; Naderi, G ; Beheshty, M. H ; Sharif University of Technology
2012
Abstract
Mixing of solid nanoparticles in viscous fluids is a key stage in synthesis of nanocomposites and can affect their final properties. A multi-step preparatory mixing is developed to synthesize the nanocomposites of layered silicate in thermosetting polymers. This study aims to investigate the influences of mixing conditions and steps taken to process the thermosetting nanocomposites on the viscoelastic properties of suspensions. We also examine subsequent influences of mixing on the microstructure and dispersion state of cured hybrids of organically modified clays in a polyester resin. The nanocomposites were prepared in a sequential mixing process developed for the model nanocomposites of...
Swelling and mechanical behavior of nanoclay reinforced hydrogel: single network vs. full interpenetrating polymer network
, Article Polymer Bulletin ; Volume 72, Issue 7 , March , 2015 , Pages 1663-1681 ; 01700839 (ISSN) ; Bagheri, R ; Kabiri, K ; Sharif University of Technology
Springer Verlag
2015
Abstract
Despite the various uses of hydrogels, one of their weaknesses is the poor gel strength. To overcome this restriction, the current study has focused on simultaneously employing an interpenetrating polymer network (IPN) structure and nanocomposite hydrogels. Through this approach, the influence of nanofiller in the single network and IPN hydrogel properties was also studied in detail. For this purpose, a novel full interpenetrating polymer network (IPN) hydrogel nanocomposite based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS)/acrylic acid (AA)–sodium acrylate (AANa) was synthesized in two steps through a facile solution polymerization with incorporation of modified bentonite (MBE) as...
Effect of alumina nanoparticles on the microstructure and mechanical durability of meltspun lead-free solders based on tin alloys
, Article Journal of Alloys and Compounds ; Volume 688 , 2016 , Pages 143-155 ; 09258388 (ISSN) ; Khodabakhshi, F ; Zareh, E ; Shahbazkhan, A ; Simchi, A ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
As one of the key technologies for high performance electronic devices, composite solders have been recently developed to improve thermal and mechanical properties of solder joints. In this research, melt spinning was employed to fabricate a lead-free based nanocomposite solder for electronic application materials via introducing Ni-coated Al2O3 nanoparticles (0.1 wt%) into a Sn-Ag-Cu ternary eutectic alloy during rapid solidification. These surface-modified nanoparticles were synthesized by an in situ chemical reduction method. The effect of rapid solidification on the distribution of reinforcing nanoparticles, microstructural evolution, and solderability of the tin alloy were studied....
Effect of carbon nanotube geometries on mechanical properties of nanocomposite via nanoscale representative volume element
, Article Journal of Solid Mechanics ; Volume 8, Issue 3 , 2016 , Pages 568-577 ; 20083505 (ISSN) ; Ghavanloo, E ; Fazelzadeh, S. A ; Sharif University of Technology
Islamic Azad University
2016
Abstract
Predicting the effective elastic properties of carbon nanotube-reinforced nanocomposites is of great interest to many structural designers and engineers for improving material and configuration design in recent years. In this paper, a finite element model of a CNT composite has been developed using the Representative volume element (RVE) to evaluate the effective material properties of nanocomposites. Based on this model, the effects of geometrical characteristics such as the aspect ratio, orientation and volume fraction of the CNTs in conjunction with the interphase behavior on the mechanical properties of the nanocomposites are elucidated and the elastic properties of a complex polymeric...
Functionalized copper oxide–zinc oxide nanocomposite: synthesis and genetic programming model of dye adsorption
, Article Desalination and Water Treatment ; Volume 57, Issue 40 , 2016 , Pages 18755-18769 ; 19443994 (ISSN) ; Chamani, H ; Kariminia, H. R ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
The functionalized copper oxide–zinc oxide nanocomposite (FCZN) was synthesized and characterized using Fourier transform infrared, scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and BET. Dye removal from aqueous solution was done in a batch system using FCZN as an adsorbent. The effects of adsorbent dosage, initial dye concentration, pH, temperature, and additive salts on dye removal were investigated. Isotherms, kinetics, and thermodynamics of dye adsorption were studied. Equilibrium and kinetic data were fitted by Langmuir isotherm and pseudo-second-order kinetic, respectively. The thermodynamic data showed that dye adsorption was spontaneous, endothermic, and...
Composites of carbon nanotubes with the blend of poly(vinylidene fluoride)/poly(vinyl acetate)
, Article Polymer (Korea) ; Volume 40, Issue 2 , 2016 , Pages 232-237 ; 0379153X (ISSN) ; Frounchi, M ; Sharif University of Technology
Polymer Society of Korea
2016
Abstract
Poly(vinylidene fluoride)/poly(vinyl acetate)/carbon nanotubes, PVDF/PVAc/CNT, composite films were prepared at various compositions via a solution casting method. The amorphous PVAc formed a miscible blend with PVDF and drastically improved dispersion of CNT in PVDF/CNT composites. Combination of ductile PVAc and rigid CNT had favorable effects on mechanical properties of PVDF. The elongation of PVDF increased from 8% to 300% with addition of 40 wt% PVAc and 0.5 wt% CNT and the modulus at 1.5 wt% CNT was almost 2.3 fold of that of the neat PVDF while retaining high ductility and tensile strength. XRD and FTIR results showed that CNT favored formation of β-crys-talline phase in PVDF. Also...
Effect of multi-pass friction stir processing on the microstructure, mechanical and wear properties of AA5083/ZrO2 nanocomposites
, Article Journal of Alloys and Compounds ; Volume 726 , 2017 , Pages 1262-1273 ; 09258388 (ISSN) ; Alipour, M ; Hamouda, A. M. S ; Matin, A ; Kord, S ; Afshari, B. M ; Koppad, P. G ; Sharif University of Technology
Abstract
In this study, multi-pass friction stir processing using zirconia nanoparticles was performed on AA5083 sheets to fabricate surface nanocomposites. Effect of using different number of passes on the microstructure, microhardness, tensile and wear properties of the specimens was investigated. Therefore, it was found that iteration of FSP consistently improves tensile properties and microhardness of the materials. This was mainly related to microstructural modification through FSP, including better dispersion of powders, finer grain size and minimum clustered particles. EBSD and TEM analysis indicated a large number of high angle grain boundaries and occurrence of continuous dynamic...
Metallurgical challenges in carbon nanotube-reinforced metal matrix nanocomposites
, Article Metals ; Volume 7, Issue 10 , 2017 ; 20754701 (ISSN) ; Safavi, M. S ; Sovizi, S ; Azarniya, A ; Chen, B ; Madaah Hosseini, H. R ; Ramakrishna, S ; Sharif University of Technology
Abstract
The inclusion of carbon nanotubes (CNTs) into metallic systems has been the main focus of recent literature. The aim behind this approach has been the development of a new property or improvement of an inferior one in CNT-dispersed metal matrix nanocomposites. Although it has opened up new possibilities for promising engineering applications, some practical challenges have restricted the full exploitation of CNTs’ unique characteristics. Non-uniform dispersion of CNTs in the metallic matrix, poor interfacial adhesion at the CNT/metal interface, the unfavorable chemical reaction of CNTs with the matrix, and low compactability are the most significant challenges, requiring more examination....
Heterogeneities in polymer structural and dynamic properties in graphene and graphene oxide nanocomposites: molecular dynamics simulations
, Article Macromolecular Theory and Simulations ; Volume 26, Issue 2 , 2017 ; 10221344 (ISSN) ; Mirjavadi, S. S ; Salem Hamouda, A. M ; Makki, H ; Sharif University of Technology
Wiley-VCH Verlag
2017
Abstract
The effect of graphene (G) and graphene oxide (GO), used as the nanofiller in polymer nanocomposites (NC), on the structural and dynamic properties of polymer chains, has been studied by means of molecular dynamics (MD) simulations. Two polymers, i.e., poly(propylene) and poly(vinyl alcohol), are employed as matrices to cover a wider range of polymer–filler interactions. The local structural properties, e.g., density profile, average Rg, and end-to-end distance as well as dynamic properties, e.g., estimated translational and orientational relaxation times, of polymer chains are studied. In addition, the interaction energies are estimated between polymers and nanofillers for different hybrid...