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Fluoride Removal from Radioactive Wastewater of UCF Plant by Adsorption
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Sepehrian, Hamid (Supervisor)
Abstract
In this research, a review on fluoride adsorption revealed that the modification of the adsorber surface with ions like Ca2+ results in great enhancement of the fluoride adsorption. It seems that the enhancement in fluoride adsorption by the modified adsorber, is mainly due to the selective chemical binding of the fluoride ion with the surface-bound ion (Ca2+), regardless of the base material itself. In order to confirm this hypothesis, two different adsorber materials namely, γ-alumina (a material, conventionally used for fluoride removal from water and wastewater) and Micro-silica (a mineral with small adsorption capacity for fluoride) were selected for further study. It was found that the...
Characterization of Elecroless Ni-P-Al2O3-SiO2 Nano-composite Coating on Aluminium
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor) ; Dolati, Abolghasem (Supervisor)
Abstract
In this study Ni-P-Al2O3-SiO2 nano composite coating developed on aluminium alloy 6061 using electroless method. Due to oxidation of aluminium, a double zincate pretreatment performed to obtain proper adhesion of coating on substrate. Effect of solution temperature and heat treatment on thickness and property of nano composite coating was studied. Furthermore, effect of concentration of nano particles in electroless solution on thickness, morphology, micro hardness, wear behavior, corrosion resistance and particle content in coating were investigated. Field emission scanning electron microscopy (FESEM, Hitachi S-4160) with energy dispersive spectroscopy (EDS) was used to evaluate morphology...
Chitosan based supramolecular polypseudorotaxane as a pH-responsive polymer and their hybridization with mesoporous silica-coated magnetic graphene oxide for triggered anticancer drug delivery
, Article Polymer (United Kingdom) ; Volume 76 , October , 2015 , Pages 52-61 ; 00323861 (ISSN) ; Mazaheri Tehrani, Z ; Jokar, S ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Chitosan based polyseudorotaxane was designed as a pH-responsive supramolecular polymeric shell around the mesoporous silica-coated magnetic graphene oxide (Fe3 O4 @GO@mSiO2 ). It was used for doxorubicin delivery at cancerous tissue in a controlled manner. The core-shell nanocarrier was formed due to electrostatic interaction between chitosan and carboxylated surface of Fe3 O4 @GO@mSiO2 . The maximum release occurred at pH 5.5 (pH of endosomes) because the shell collapsed at this pH. The drug nanocarrier has potential application in tumor therapy due to good pH-sensitive behavior, improved solubility and high colloidal stability in...
Hydrogel nanocomposite based on chitosan-g-acrylic acid and modified nanosilica with high adsorption capacity for heavy metal ion removal
, Article Iranian Polymer Journal (English Edition) ; Volume 24, Issue 9 , September , 2015 , Pages 725-734 ; 10261265 (ISSN) ; Mazaheri Tehrani, Z ; Salimi, H ; Banazadeh, A ; Abedini, N ; Sharif University of Technology
Springer-Verlag London Ltd
2015
Abstract
In this study, a novel hybrid hydrogel based on chitosan, acrylic acid and amine-functionalized nanosilica was prepared and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. This hydrogel nanocomposite was used for removal of Co2+, Cu2+, Pb2+ and Zn2+ ions from aqueous solution. The metal ion adsorption was measured by inductively coupled plasma mass spectrometry. The adsorption behavior showed that the presence of modified nanosilica enhanced the porosity of the hydrogel network and affected its adsorption capacity in response to different parameters such as nanosilica content, metal ion concentration, adsorbent content,...
Magnetic graphene oxide mesoporous silica hybrid nanoparticles with dendritic pH sensitive moieties coated by PEGylated alginate-co-poly (acrylic acid) for targeted and controlled drug delivery purposes
, Article Journal of Polymer Research ; Volume 22, Issue 8 , 2015 ; 10229760 (ISSN) ; Shakerpoor, A ; Tehrani, Z. M ; Bumajdad, A ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
In this study synthesis of a drug delivery system (DDS) is described which has several merits over its counterparts. In order to synthesize this nano-carrier, graphene oxide nano-sheets are used to accommodate MCM-41 nanoparticles. Furthermore Fe3 O4 nanoparticles are introduced to this nano-material to produce a traceable nanoparticle. Since cancerous tissues have lower pH than healthy tissues, pH-sensitive oligomers are attached to this nano-material. Finally the nano-carrier is wrapped by a biocompatible shell (PEGylated sodium alginate); this polymeric shell makes the DDS capable of a more controllable drug release. By measuring in vitro situation, ‘loading content%’...
Nano-scale modification of polysulfone membrane matrix and the surface for the separation of chromium ions from water
, Article Chemical Engineering Journal ; Volume 267 , May , 2015 , Pages 306-316 ; 13858947 (ISSN) ; Nematollahzadeh, A ; Mousavi, S. A ; Sharif University of Technology
Elsevier
2015
Abstract
In this study, aiming at hexavalent chromium removal from aqueous solutions, different strategies were proposed for developing hydrophilic and surface functional polysulfone (PSf) membrane. In addition to PSf membrane, three different types of membranes were prepared by addition of SiO2 nano-particles to the dope solution and/or by deposition of polydopamine (PDA) layer on the surface of the membranes. The membranes (i.e. PSf, PSf/PDA, PSf/SiO2 and PSf/SiO2/PDA) were characterized by different techniques. The membranes' transport properties and the separation performance were studied using a filtration unit operated at a continuous dead-end flow mode. The kinetics and the separation...
The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating
, Article Journal of Nanoparticle Research ; Volume 17, Issue 4 , April , 2015 ; 13880764 (ISSN) ; Tehrani, Z. M ; Mahmoudi, N ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating...
Ionic liquid-based ordered mesoporous organosilica-supported copper as a novel and efficient nanocatalyst for the one-pot synthesis of Biginelli products
, Article Microporous and Mesoporous Materials ; Volume 204, Issue C , 2015 , Pages 269-275 ; 13871811 (ISSN) ; Hosseinpoor, F ; Karimi, B ; Hajati, S ; Sharif University of Technology
Abstract
The preparation, characterization and catalytic application of a novel copper-loaded ionic liquid-based periodic mesoporous organosilica (Cu@PMO-IL) are described. The mesoporous structure of the Cu@PMO-IL material is characterized by transmission electron microscopy (TEM) and nitrogen adsorption-desorption analysis. The thermal stability of the material is also determined by thermal gravimetric analysis (TGA). The presence of copper species in the material framework is confirmed by X-ray photoelectron spectroscopy (XPS) and elemental analysis (EA). The catalytic application of Cu@PMO-IL nanocatalyst is then investigated in the Biginelli condensation of different aldehydes with urea and...
Silver nanoparticles supported on silica-coated ferrite as magnetic and reusable catalysts for oxidant-free alcohol dehydrogenation
, Article RSC Advances ; Volume 5, Issue 29 , Jan , 2015 , Pages 22503-22509 ; 20462069 (ISSN) ; Shakourian Fard, M ; Ehyaei, N ; Mahmoodi Hashemi, M ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
Silver (0) nanoparticles supported on silica-coated ferrite were synthesized to be used as an efficient and recyclable heterogeneous catalyst for oxidant-free dehydrogenation of alcohols to the corresponding carbonyl compounds. The catalyst can be easily recovered and reused for 8 reaction cycles without considerable loss of activity. The facile recovery of the catalyst is carried out by applying an external magnetic device. The catalyst was fully characterized by the techniques of TEM, SEM, XRD, EDS, ICP-AES, and VSM. This journal is
Experimental investigation of heavy oil recovery by continuous/WAG injection of CO2 saturated with silica nanoparticles
, Article International Journal of Oil, Gas and Coal Technology ; Volume 9, Issue 2 , 2015 , Pages 169-179 ; 17533317 (ISSN) ; Khezrnejad, A ; Shahrokhi, O ; Ghazanfari, M. H ; Vossoughi, M ; Sharif University of Technology
Inderscience Enterprises Ltd
2015
Abstract
In this work, application of CO2 saturated with silica nanoparticles in continuous/water alternating gas (WAG) injection for heavy oil recovery was investigated which has been rarely attended in the available literature. Core displacement tests were conducted to monitor heavy oil recovery in both continuous and WAG injection schemes. It has been observed that for continuous nano-saturated CO2 injection, the oil recovery is higher than pure CO2 injection. This observation might be explained by alteration of rock wettability to a more water-wet condition. In WAG injection scheme, water breakthrough happened later in nano-saturated CO2 than pure CO2 injection. This delayed water breakthrough...
Polyelectrolyte nanocomposite membranes using imidazole-functionalized nanosilica for fuel cell applications
, Article Journal of Macromolecular Science, Part B: Physics ; Volume 54, Issue 1 , Nov , 2015 , Pages 17-31 ; 00222348 (ISSN) ; Ghaffarian, S. R ; Nouri, M ; Jaafarnia, E ; Haghighi, A. H ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
The preparation and characterization of a new type of nanocomposite polyelectrolyte membrane, based on DuPont Nafion/imidazole-modified nanosilica (Im-Si), for direct methanol fuel cell applications is described. Related to the interactions between the protonated imidazole groups, grafted on the surface of nanosilica, and negatively charged sulfonic acid groups of Nafion, new electrostatic interactions can be formed in the interface of Nafion and Im-Si which result in both lower methanol permeability and also higher proton conductivity. Physical characteristics of these manufactured nanocomposite membranes were investigated by scanning electron microscopy, thermogravimetry analysis,...
Synthesis and Investigation on the Properties of Silica-Graphene Oxide Nanocomposite Coating
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
The investigations on hydrophobic surfaces have attracted lots of intrests in science and technology. Silica sols have been used extensively in the area of producing hydrophobic coatings. On the other hand, carbon-based materials have attracted of a great deal of scientific interest in recent years. The purpose of this research is synthesis and investigation on the properties of Silica- Graphene Oxide nanocomposite coating.Graphene Oxide synthesized by using Hummer’s method. Silica nanoparticles were prepared using sol-gel process and tetraethylorthosilicate (TEOS) as precursor. The surface hydroxyl groups of silica nanoparticles are replaced with Methyl groups by treatment with...
Sol-gel-based silver nanoparticles-doped silica - Polydiphenylamine nanocomposite for micro-solid-phase extraction
, Article Analytica Chimica Acta ; Volume 886 , July , 2015 , Pages 56-65 ; 00032670 (ISSN) ; Banihashemi, S ; Sharif University of Technology
Elsevier
2015
Abstract
A nanocomposite of silica-polydiphenylamine doped with silver nanoparticles (Ag-SiO2 -PDPA) was successfully synthesized by the sol-gel process. For its preparation, PDPA was mixed with butanethiol capped Ag nanoparticles (NPs) and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO2 spheres. The surface characteristic of nanocomposite was investigated using scanning electron microscopy (SEM). In this work the Ag-SiO2 -PDPA nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction (μ-SPE) of some selected pesticides. An amount of 15 mg of the prepared sorbent was used to extract and...
PEG-co-polyvinyl pyridine coated magnetic mesoporous silica nanoparticles for pH-responsive controlled release of doxorubicin
, Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 64, Issue 11 , 2015 , Pages 570-577 ; 00914037 (ISSN) ; Mazaheri Tehrani, Z ; Bennett, C ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
In the present work a pH responsive drug nanocarrier based on magnetic mesoporous silica nanoparticles (MMSN) and polyethylene glycol-co-polyvinyl pyridine (PEG-co-PVP) was prepared. The core-shell nanocarrier was formed due to electrostatic interaction between protonated polyvinyl pyridine and surface modified MMSN with carboxylate groups. This carrier was used for pH-controllable doxorubicin release. The maximum release was occurred at pH 5.5 (pH of endosomes). This carrier was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-Vis spectrophotometer, scanning electron microscope, and high-resolution transmission electron microscope techniques. Also the...
Study of synergistic toughening in a bimodal epoxy nanocomposite
, Article Journal of Reinforced Plastics and Composites ; Volume 34, Issue 4 , February , 2015 , Pages 281-292 ; 07316844 (ISSN) ; Khamesinia, A ; Bagheri, R ; Kouchakzadeh, M. A ; Abadyan, M ; Sharif University of Technology
SAGE Publications Ltd
2015
Abstract
Toughening of epoxy with different types of modifiers produces a bimodal blend that might show better fracture resistance in comparison with single-modified ones. In this research, bimodal epoxy formulations including mixtures of glass microsphere and silica nanoparticles are explored for possible synergistic toughening. The influence of composition on the glass transition temperature (Tg), tensile characteristics, and fracture toughness (KIC) is investigated. Interestingly, a synergism in fracture toughness is observed when mixtures of modifiers were incorporated. For the fixed overall modifier content, KIC is higher when the volume fraction of glass microsphere is lesser than the volume...
synergistic toughening in ternary silica/hollow glass spheres/epoxy nanocomposites
, Article Polymer - Plastics Technology and Engineering ; Volume 54, Issue 6 , 2015 , Pages 581-593 ; 03602559 (ISSN) ; Bagheri, R ; Kouchakzadeh, M. A ; Abadyan, M ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
Herein, the fracture toughness of ternary epoxy systems containing nanosilica and hollow glass microspheres (HGMS) is investigated. The experimental measurements reveal synergistic fracture toughness in some hybrid compositions: The incorporation of 10 phr of HGMS and nanosilica alone modify the fracture toughness of epoxy by 39% and 91%, respectively. However, use of 10 phr hybrid modifier can enhance the fracture toughness of the resin up to 120%. Observations reveal different toughening mechanisms for the blends i.e., plastic deformation for silica nanoparticles and crack bifurcation for HGMS. Both of these toughening mechanisms additively contribute to the synergism in ternary epoxies
Chemically modified organic/inorganic nanoporous composite particles for the adsorption of reactive black 5 from aqueous solution
, Article Reactive and Functional Polymers ; Volume 86 , 2015 , Pages 7-15 ; 13815148 (ISSN) ; Shojaei, A ; Karimi, M ; Sharif University of Technology
Elsevier
2015
Abstract
In the present work, we report a chemically modified polyacrylamide/silica nanoporous composite adsorbent for the removal of reactive black 5 (RB5) azo dye from aqueous solutions. The composite adsorbent was synthesized in a packed bed and modified by ethylenediamine (EDA). The adsorbent was characterized by Fourier transformation infrared (FT-IR), thermogravimetric analysis (TGA), thermoporometry, Brunauer, Emmett and Teller (BET) method and scanning electron microscopy (SEM). Mechanical stability of the adsorbent was examined in a packed bed by following the back-pressure of the column. Pore diameter of the composite adsorbent in dry and wet states was estimated to be about 18.71 nm and...
The effect of mesoporous silica nanoparticle surface chemistry and concentration on the α-synuclein fibrillation
, Article RSC Advances ; Volume 5, Issue 75 , Jul , 2015 , Pages 60966-60974 ; 20462069 (ISSN) ; Morshedi, D ; Doostkam, M ; Yaghmaei, S ; Aliakbari, F ; Singh, G ; Arpanaei, A ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
The aggregation of an amyloid protein, α-synuclein (α-Syn), has been suggested as a potential cause of Parkinson's and several other neurodegenerative diseases. To explore the possibility of using nanoparticle-based therapeutic agents for the treatment of such diseases, we investigated the influence of surface chemistry and concentration of mesoporous silica nanoparticles (MSNPs) on the fibrillation of recombinant human α-Syn protein in the present work. Bare MSNPs as well as MSNPs of different surface functionalities, including 3-(2-aminoethyl amino) propyltrimethoxysilane (AAS), succinic anhydride (carboxyl), and polyethyleneimine (PEI) were prepared and characterized by electron...
The Effect of Surfactant Agents on the Superhydrophobic Properties of Silica Coatings Synthesis by Sol-gel
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
The purpose of this research is producing one phase silica superhydrophobic coating by sol-gel method and drying temperature less than 200 degrees. For preparing micrometer and nanometer scaled hierarchical structure based on silica, TEOS precursor and Fumed Silica nanoparticles were used by density of 43/30 cc/lit and 6/52 gr/lit in order to provide desired roughness in the range of 40 nm. Moreover, HMDS surface modifying agent was used for reducing the surface energy of coating, which is not a danger to the environment in comparison to the same substances. The best Contact Angle is 155 degree and the best Sliding Angle is less than 5 degree. For instance, it was created with the...
Synthesis and application of silica aerogel-MWCNT nanocomposites for adsorption of organic pollutants
, Article Scientia Iranica ; Volume 17, Issue 2 F , 2010 , Pages 122-132 ; 10263098 (ISSN) ; Amirkhani, L ; Moghaddas, J. S ; Ahadian, M. M ; Sharif University of Technology
Abstract
Silica aerogel-multi wall carbon nanotube composites were synthesized successfully with a waterglass precursor and an ambient pressure drying method. Pure silica aerogels are so fragile that they cannot be used easily. Carbon nanotubes (MWCNT) were used as reinforcements to strengthen the mechanical properties of pure silica aerogels. Results show that inserting small amounts of MWCNT causes silica aerogels to monolith. By addition of MWCNT, monolith nanocomposites were produced with 800 m2/g surface area and a 140° contact angle. Results show that the silica aerogels and reinforced composites have an excellent adsorption property for the removal of organic pollutants from water. The average...