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silane
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Antistatic Polyurethane Coating Containing Zirconia Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
In this study, antistatic waterborne polyurethane coating containing zirconia nanoparticles is made and applied on 304 stainless steel substrates at weight percentage of 0.66, 1.3, 3, 4.5 and 6% zirconia nanoparticles. For synthesis of hydrophilic isocyanate prepolymer, isocyanate prepolymer is modified by hydrophilic polyethylene glycol with molecular weight 600, 1000 and 4000. For ensuring of modification condition and stability of hydrophilic isocyanate prepolymer in aqua solution, FTIR and stability tests are employed, respectively. In order to create antistatic properties of these coatings, semi - conductive zirconia nanoparticles are used. To improve the distribution of zirconia...
Investigation of the Effect Recycled Nanosilica from Battery Separator by Pyrolysis Method on Mechanical Properties and Adhesion between Rubber and Steel
, M.Sc. Thesis Sharif University of Technology ; Pircheraghi, Gholamreza (Supervisor)
Abstract
Creating sustainable development in today's human societies is essential, one of the pillars of achieving this important goal is environmental protection. Thus, waste management as a new challenge is leading engineers. Lead-acid battery waste is one of the sources of environmental pollution. Lead-acid battery separators contain 50% recyclable nanosilica. The main challenge of recycling nanosilica from separators is the presence of significant amounts of 6 to 9% wt.% of lead and 5% by weight of other impurities. Therefore, in the present study, lead trapped in the separating pores is removed using mechanical washing or abrasive washing. Then, the quality of recycled nanosilica is evaluated...
Synthesis and Properties of Functional Super Hydrophobic TiO2
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Titanium nano-oxide (TiO2) coatings have been used for self-cleaning, antimicrobial, and dust-proof designs. The degree of wetting of a solid surface with water in humid air depends on how the surface tension of the existing phases relates. The ratio between these tensions estimates the contact angle between a drop of water and the surface on which it is placed. A contact angle above 150 º is essential for surface overflow. In this study, 18 different combinations of titanium oxide and FAS, PDMS and PMS nanoparticles were obtained with a static contact angle of 165 to 150 º and a dynamic contact angle of 7 º.1 to 4.5 º. Following the measurement of water droplet slip speed on a sloping...
Synthesis and Surface Modification of Manganese Oxide Nanoparticles as MRI Contrast Agent
, M.Sc. Thesis Sharif University of Technology ; Madaah Hosseini, Hamid Reza (Supervisor)
Abstract
Recently, preparation of biofunctionalized nanoparticles with specific magnetic properties has received great attention for medical imaging. Targeting magnetic nanoparticles with high signal in magnetic resonance imaging (MRI) could be a powerful tissue imaging and cellular tracking agent. Main purpose of this research is the synthesis of Mn3O4@polymer composite nanoparticles as a positive MRI contrast agent. Nanoparticles were prepared by modified microwavepolyol and precipitation method with average particle size of 18 and 3nm.Respectivelythe effect of diffrent parameters such as time, surfactant and the presence of water in polyol method and the amount ofpolyethylene glycol as surfactant...
Characterization of Morphology and Properties of Polydimethylsiloxane/Nanodiamond Nanocomposite
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor)
Abstract
Polydimethylsiloxane (PDMS) is one of the most important organosilicon elastomers. This polymer has a wide application such as medical engineering due to the unique characteristics, variety and ease of manufacture. Nowadays, the use of nanoparticles such as carbon nanotubes for improving the properties of elastomers is highly regarded owing to the fact that the improvement of properties such as mechanical properties broadens the applications of PDMS. Diamond nanoparticles has been the focus of numerous researchers in the past decade. In fact, nanodiamond has a good mechanical abrasion and thermal properties. In addition, the investigations proved that the nanoparticle is valuable in terms of...
Deposition and Properties of ZIF-8/SiO2 Hydrophobi Anti-Corrosion Coating
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
In this research, a coating was created on the steel surface using the network structure of zeolite imidazolate-8 (ZIF-8) and its effect on the corrosion behavior of steel was investigated. Then, the effect of two coupling agents, mercaptopropyltriethoxysilane (MPTES) and aminopropyltriethoxysilane (APTES) on the coating and its anti-corrosion properties was investigated. Then, in order to make a hydrophobic coating, the substrate was first coated with ZIF-8 and then a combination of silica nanoparticles plus hexamethyldisilazane (HMDS) and polymethylhydrogensiloxane (PMHS) was added to the initial solution and then coating was done. As a result of this process, the contact angle of water...
Quantitative in vivo microsampling for pharmacokinetic studies based on an integrated solid-phase microextraction system
, Article Analytical Chemistry ; Volume 79, Issue 12 , 2007 , Pages 4507-4513 ; 00032700 (ISSN) ; Eshaghi, A ; Musteata, F. M ; Ouyang, G ; Pawliszyn, J ; Sharif University of Technology
2007
Abstract
An integrated microsampling approach based on solid-phase microextraction (SPME) was developed to provide a complete solution to highly efficient and accurate pharmacokinetic studies. The microsampling system included SPME probes that are made of poly(ethylene glycol) (PEG) and C18-bonded silica, a fast and efficient sampling strategy with accurate kinetic calibration, and a high-throughput desorption device based on a modified 96-well plate. The sampling system greatly improved the quantitative capability of SPME in two ways. First, the use of the C18-bonded silica/PEG fibers minimized the competition effect from analogues of the target analytes in a complicated sample matrix such as blood...
Carbosilane dendrimers: Drug and gene delivery applications
, Article Journal of Drug Delivery Science and Technology ; Volume 59 , 2020 ; Ahmadvand, S ; Ahmadi, S ; Fatahi, Y ; Dinarvand, R ; Bagherzadeh, M ; Rabiee, M ; Tahriri, M ; Tayebi, L ; Hamblin, M. R ; Sharif University of Technology
Editions de Sante
2020
Abstract
Carbosilane dendrimers are a particular type of dendrimer structure that has been used as delivery vehicles for drugs and nucleic acids. They have a defined structure according to their generation number, and their terminal groups can be rendered cationic or anionic. The cationic charges can address the limitation of electrostatic repulsion between the negatively charged phosphate groups of nucleic acids and negatively charged cell membranes. Specific drugs can be loaded into the central part of the dendrimer or attached at the exterior, and the overall positive charge may improve the efficacy of anti-inflammatory drugs. One promising feature of dendrimers is their non-toxicity both in vitro...
Biohybrid oxidized alginate/myocardial extracellular matrix injectable hydrogels with improved electromechanical properties for cardiac tissue engineering
, Article International Journal of Biological Macromolecules ; Volume 180 , 2021 , Pages 692-708 ; 01418130 (ISSN) ; Mashayekhan, S ; Baheiraei, N ; Pourjavadi, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Injectable hydrogels which mimic the physicochemical and electromechanical properties of cardiac tissue is advantageous for cardiac tissue engineering. Here, a newly-developed in situ forming double-network hydrogel derived from biological macromolecules (oxidized alginate (OA) and myocardial extracellular matrix (ECM)) with improved mechanical properties and electrical conductivity was optimized. 3-(2-aminoethyl amino) propyltrimethoxysilane (APTMS)-functionalized reduced graphene oxide (Amine-rGO) was added to this system with varied concentrations to promote electromechanical properties of the hydrogel. Alginate was partially oxidized with an oxidation degree of 5% and the resulting OA...
PO43--Loaded zif-8-type metal-organic framework-decorated multiwalled carbon nanotube synthesis and application in silane coatings for achieving a smart corrosion protection performance
, Article Industrial and Engineering Chemistry Research ; Volume 61, Issue 32 , 2022 , Pages 11747-11765 ; 08885885 (ISSN) ; Ramezanzadeh, M ; Fedel, M ; Ramezanzadeh, B ; Mahdavian, M ; Sharif University of Technology
American Chemical Society
2022
Abstract
In this research study, interfacial assembled nanoporous zeolitic imidazolate framework (ZIF-8) multiwalled oxidized carbon nanotubes (MW-OCNTs) were developed and introduced into a silane coating. To analyze the destructive behavior of the nanoparticles exposed to salty solutions with three distinctive pHs of 2, 7.5, and 12, various types of tests such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and inductively coupled plasma (ICP) were accomplished. The XRD test revealed that the main characteristic peaks of ZIF-8 were eliminated and/or their intensity decreased. In accordance with the obtained data from the XRD test, nanoparticles at pH = 2 had been...
Effect of pH, citrate treatment and silane-coupling agent concentration on the magnetic, structural and surface properties of functionalized silica-coated iron oxide nanocomposite particles
, Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 44, Issue 3 , December , 2011 , Pages 618-627 ; 13869477 (ISSN) ; Yaghmaei, S ; Roostaazad, R ; Bardania, H ; Arpanaei, A ; Sharif University of Technology
Abstract
Superparamagnetic iron oxide nanoparticles were synthesized by coprecipitation of iron chloride salts at various pH values (9, 10, 11 and12) that were adjusted using an ammonia solution. Increasing the pH from 9 to 12 led to decreases in the size of iron oxide nanoparticles from 7.9±1.4 to 5±0.6 nm and the saturation magnetization (M s) from 82.73 to 67.14 emu/g, respectively, when analyzed with transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). X-ray diffraction patterns as well as M s values showed that magnetite is the dominantly synthesized phase in the examined pH values. Unmodified iron oxide nanoparticles were coated with silica via the hydrolysis and...
Fabrication or preparation and characterization of new modified MCM-41/PSf nanocomposite membrane coated by PDMS
, Article Separation and Purification Technology ; Volume 80, Issue 3 , August , 2011 , Pages 556-565 ; 13835866 (ISSN) ; Pakizeh, M ; Shafiee, A. R ; Mansoori, S. A. A ; Sharif University of Technology
2011
Abstract
MCM-41 nanoparticles were prepared by in situ assembly of inorganic precursors and CTAB. The structure of nanoparticles was characterized by XRD, TEM, particle size analysis, N2 adsorption techniques. The surface modification of particles in order to perfect dispersion in polysulfone (PSf) matrix was performed by dimethyldichlorosilane (DMDCS) and aminopropyltrimethoxysilane (APTMS) as new modification agents. Thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and SEM analysis were applied to investigate thermal stability, glass transition temperature and quality of distribution of particle in the nanocomposite membrane, respectively. The PDMS was used to coat the...
Silane–based modified papers and their extractive phase roles in a microfluidic platform
, Article Analytica Chimica Acta ; Volume 1128 , 2020 , Pages 31-41 ; Rezvani, O ; Bagheri, H ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Herein, some (modified) paper–based substrates were prepared and utilized as extractive phases in a microfluidic device and their extraction performances examined for analytes with different polarities. Reagents including hexadecyltrimethoxysilane (HDTMS), phenyltrimethoxysilane (PTES), (3-aminopropyl) triethoxysilane (APTES) and 3–(2,3–epoxypropoxy) propyltrimethoxysilane (EPPTMOS) were implemented for the modification process. Due to the induction of different silane functional groups, it was anticipated to have various interactions for the tested analytes. Eventually, the prepared paper sheets were used as extractive phases for solid–phase extraction within a microfluidic system. The...
Oxidative deprotection of silylethers, acetals and ketals by oxygen or air in presence of manganese and cobalt salts of 4-aminobenzoic acid supported on silica gel as catalyst
, Article Synthetic Communications ; Volume 30, Issue 10 , 2000 , Pages 1857-1863 ; 00397911 (ISSN) ; Kalantari, F ; Sharif University of Technology
Marcel Dekker Inc
2000
Abstract
Oxidative deprotection of silylethers, acetals and ketals, to their corresponding alcohols, aldehydes and ketones have been achieved using oxygen or air in the presence of cobalt and manganese salts of 4-aminobenzoic acid supported an silica gel as catalysts. Reactions are clean and catalysts can be recovered easily and reused repeatedly
Silica nanoparticle surface chemistry: An important trait affecting cellular biocompatibility in two and three dimensional culture systems
, Article Colloids and Surfaces B: Biointerfaces ; Volume 182 , 2019 ; 09277765 (ISSN) ; Taebnia, N ; Yaghmaei, S ; Shahbazi, M. A ; Mehrali, M ; Dolatshahi Pirouz, A ; Arpanaei, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Great advantages bestowed by mesoporous silica nanoparticles (MSNs) including high surface area, tailorable pore diameter and surface chemistry, and large pore volume render them as efficient tools in biomedical applications. Herein, MSNs with different surface chemistries were synthesized and investigated in terms of biocompatibility and their impact on the morphology of bone marrow-derived mesenchymal stem cells both in 2D and 3D culture systems. Bare MSNs (BMSNs) were synthesized by template removing method using tetraethylorthosilicate (TEOS) as a precursor. The as-prepared BMSNs were then used to prepare amine-functionalized (AMSNs), carboxyl-functionalized (CMSNs) and polymeric...
Silane functionalization of nanodiamond for polymer nanocomposites-effect of degree of silanization
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 506 , 2016 , Pages 254-263 ; 09277757 (ISSN) ; Shojaei, A ; Sharif University of Technology
Elsevier B.V
2016
Abstract
The silanization of nanodiamond (ND) was successfully carried out by using the esterification reaction of hydrolyzed vinyltrimethoxysilane (VTS) in alcoholic solution. The surface carboxylic group of ND was first enhanced by thermal oxidation to increase the degree of esterification reaction. The extent of silane functionalization of ND was controlled by varying the weight ratio of VTS and oxidized ND (oxND), from 2:1 to 10:1 (w/w) in the functionalization reaction medium. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) revealed that the highest degree of silanization occurred at VTS/oxND of 5:1 (w/w), while more silane concentrations resulted in...
Network structure and mechanical properties of polydimethylsiloxane filled with nanodiamond – Effect of degree of silanization of nanodiamond
, Article Composites Science and Technology ; Volume 142 , 2017 , Pages 227-234 ; 02663538 (ISSN) ; Shojaei, A ; Sharif University of Technology
Abstract
Reinforcement of polydimethylsiloxane (PDMS) was investigated using untreated nanodiamond (uND) and silane functionalized ND (sND) at various degrees of silanization. Scanning electron microscopy revealed an improved dispersion of ND in PDMS by silanization. The incorporation of uND and sNDs enhanced tensile strength up to 45% and 70%, respectively; however, greater improvement was observed for sNDs at very low concentrations, e.g. 0.2 wt%. The much improvement in crosslinking density, analyzed by Flory-Rehner model and Mooney-Rivlin plot, and interfacial interaction, characterized by Kraus and Cunneen-Russell plots, was also observed for sNDs. Interestingly, it was found that the extent of...
Effects of surface modified nanosilica on drilling fluid and formation damage
, Article Journal of Petroleum Science and Engineering ; Volume 194 , 2020 ; Bedrikovetsky, P ; Mahani, H ; Khoshsima, A ; Aghaei, H ; Kalateh Aghamohammadi, M ; Habibi, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Despite the fact that hydrophobic nanosilica can improve the stability of water/oil emulsion, there exist controversies pertaining to its influence on oil-based drilling fluid rheological behavior and the subsequent formation damage. The present study addresses the above using a surface modified nanosilica, where the particles were functionalized with different silane-based groups to alter their hydrophilicity: 3-glycidoxypropyl-triethoxy silane (GPTS) and combined GPTS and propyl silane (PGPTS). The NPs were characterized through FTIR analysis, particle size, and zeta-potential measurements followed by flow behavior experiments, core-scale mud flow tests, Computed Tomography (CT) scanning...
Evaluation of the corrosion protection properties of an epoxy coating containing sol-gel surface modified nano-zirconia on mild steel
, Article RSC Advances ; Volume 5, Issue 36 , Mar , 2015 , Pages 28769-28777 ; 20462069 (ISSN) ; Mahdavian, M ; Karimi, E ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
In this study, the effect of surface modified nano-zirconia (nano-ZrO2) on the corrosion protection of epoxy coating on mild steel was investigated. An organosilane (trimethoxy methyl silane) was used as a surface modifier to improve the dispersability of the inorganic nanoparticles in the organic coating matrix. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to characterize the sol-gel surface modified nanoparticles. The dispersability of the modified and unmodified nano-zirconia in an epoxy coating was examined by field emission-scanning electron microscopy (FE-SEM). Electrochemical impedance spectroscopy (EIS) and salt spray were employed to...
In-situ preparation and characterization of ultra-high molecular weight polyethylene/diamond nanocomposites using bi-supported Ziegler-Natta catalyst: effect of nanodiamond silanization
, Article Materials Today Communications ; Volume 14 , March , 2018 , Pages 53-64 ; 23524928 (ISSN) ; Ramezani Saadatabadi, Ahmad ; Amini, M ; Kheradmand, A ; Shsrif University of Technology
Elsevier Ltd
2018
Abstract
In this study, reinforcement of ultra-high molecular weight polyethylene (UHMWPE) was investigated using the sol-gel surface modified diamond nanoparticles (NDs). Nanocomposite samples were synthesized via in-situ polymerization using bi-supported Ziegler-Natta catalyst. Fourier transform infrared spectroscopy, thermogravimetric analysis and contact angle measurements proved the proper silanization (∼1.9%) of NDs. Characterization of the catalysts revealed decrease in the activity of catalysts in presence of NDs which were responsible for the lower average molecular weight of the samples. Field emission scanning electron microscopy revealed an improved dispersion of the modified NDs in...