Loading...
Search for: polycarbonate
0.004 seconds
Total 38 records

    Synthesis and Optical Properties of Cadmium Selenide Thin Films and Nanowires

    , M.Sc. Thesis Sharif University of Technology Kalhori, Hossein (Author) ; Iraji Zad, Azam (Supervisor) ; Dolati, Abolghasem (Supervisor)
    Abstract
    The interesting properties of metallic and semiconductor nanowires provide many applications in electronic and optoelectronic devices. In this project, we have synthesized Cu and CdSe nanowires using electrodeposition method. To adjust deposition bath conditions and characterize the structure of deposit first we prepared CdSe thin film on ITO substrates. The used solution was contained 0.1 M CdSO4+ 0.1 mM SeO2 in the acidic situation with pH=2.5. The best reduction potential was determined about -0.5 V. The XPS and XRD analyses showed that the ratio of cadmium to selenium in the films was 1:1 and the film’s structure is amorphous. Optical band gap of the cadmium selenide films was obtained... 

    Preparation and Surface Modification of PC Membranes for Gas Separation

    , M.Sc. Thesis Sharif University of Technology Sedghi, Saeed (Author) ; Soltanieh, Mohammad (Supervisor) ; Goodarznia, Iraj (Supervisor)
    Abstract
    The gas separation properties of polycarbonate (PC) membranes were investigated in this study. These membranes were prepared via dry and dry-wet phase inversion technique. Pure O2, N2, and CO2 gases were permeated through prepared membranes. The effects of membrane preparation conditions, including solvent type, non-solvent type, non-solvent/solvent volumetric ratio, polymer weight fraction, and drying temperature on the gas separation properties of dry PC membranes were investigated using Taguchi experimental design. Taguchi analysis show that polymer weight fraction offers the most important effect on the separation characteristics of the dry PC membranes. To get the highest... 

    Synthesis of Palladium Nanowires for Hydrogen Gas Sensor by Field Ionization

    , M.Sc. Thesis Sharif University of Technology dolatkhah, Naeme (Author) ; Irajizad, Azam (Supervisor)
    Abstract
    The interesting properties of metallic nanowires provide many applications in electronic sensors. In this project, we have synthesized Pd nanowires using electrodeposition method. These nanowires are useful for hydrogen sensors by measuring field ionization current in gas. In this project, Pd nanowires were synthesized by electrochemical deposition method in PCT template with 100 nm pore size. The used solution was contained 2mM PdCl2 + 0.1M HCl. The best reduction potential was determined about -0.2V and the best time for synthesizing nanowires was 7 minutes. Chronoampermetric diagrams showed four steps, capacitive current, growth in the holes, reaching to the surface of PCT and the growth... 

    Preparation of Polycarbonate Membrane for Industrial Wastewater Treatment in Membrane Bioreator

    , M.Sc. Thesis Sharif University of Technology Nazemi Dashtarjandi, Saeed (Author) ; Mousavi, Abbas (Supervisor) ; Bastani, Dariush (Supervisor)
    Abstract
    Today, membrane bioreactors (MBRs) process is one of the most important options in industrial and municipal wastewater treatment. In MBRs, membrane has an essential influence on their performance. In this study, polycarbonate was exploited as membrane to evaluate its performance in MBR since it has excellent mechanical properties. However, polycarbonate is brittle and breaks at low elongation at room temperature. Solution blending was utilized to improve polycarbonate’s properties. Blending membrane was characterized and assessed by scanning electron microscopy (SEM) and tensile strength. Polycarbonate solution blending with polyurehatne which has excellent toughness and flexibility enhance... 

    Processing and Characterization of Fracture Behavior of Hybrid Epoxy Nanocomposite Modified with Polycarbonate

    , M.Sc. Thesis Sharif University of Technology Amini NajafAbadi, Leila (Author) ; Bagheri, Reza (Supervisor)
    Abstract
    Epoxy resins have good mechanical and thermal properties, high chemical resistance and low shrinkage during cure but in spite of these good properties,they are brittle and this limits the usage of them. Adding a second, soft or rigid, phase has been always an effective strategy to improve the toughness of epoxy. Rigid phase used in resins are divided into organic and inorganic. The aim of this study is to increase epoxy toughness, maintaining mechanical properties and study effect of silica and polycarbonate on fracture toughness simultaneously. Mechanical properties including yield strength and elastic modulus are evaluated by pressure test. Additionally fracture toughness and three... 

    Study on Structure, Mechanical Properties, and Flammability of PC/ABS

    , M.Sc. Thesis Sharif University of Technology Alaei, Yasaman (Author) ; Bagheri, Reza (Supervisor) ; Seyed Reyhani, Morteza (Supervisor)
    Abstract
    Polycarbonate (PC) is known as one of the engineering plastics with remarkable mechanical properties, but the application of this polymer is limited due to its high notch sensitivity. Blending polycarbonate with other polymers such as acrylonitrile butadiene styrene (ABS) is a method to resolve this disadvantage. PC/ABS blends are commonly used in automotive industry, electrical and electronic devices. As PC and ABS are not completely miscible, a variety of compatibilizers are used to achieve a suitable microstructure and high engineering properties. Considering crucial applications of PC/ABS blends, different flame retardants are also used to reduce the flammability. These flame retardants... 

    The Impedimetric Human Papiloma Virous DNA Biosensor Fabrication Based on Gold Nanotubes

    , Ph.D. Dissertation Sharif University of Technology Shariati, Mohsen (Author) ; Ghorbani, Mohammad (Supervisor) ; Sasanpour, Pezhman (Supervisor)
    Abstract
    An impedimetric human papilloma virus (HPV) DNA biosensor based on gold nanotubes (AuNTs) in label free detection was materialized. The AuNTs decorated nanoporous polycarbonate (AuNTs-PC) template as biosensor electrode was fabricated by electrodeposition method. The single strand DNA (ss-DNA) probe was covalently immobilized onto the AuNTs-PC electrode. The hybridization of target sequences with the ss-DNA probe was observed by the electrochemical impedance spectroscopy (EIS). The biosensor showed high selectivity and could differentiate between the complementary, mismatch and non-complementary DNA sequences. The EIS measurements were matched to Randle's equivalent circuit. The... 

    Processing and Characterization of Microstructure and Mechanical Properties of PC/PBT Blend

    , M.Sc. Thesis Sharif University of Technology Shabani, Farzan (Author) ; Bagheri, Reza (Supervisor)
    Abstract
    Blend of Polycarbonate/ poly(butylene terephthalate) is among the most famous blends of polycarbonate/polyester with vast engineering applications and unique properties. Miscibility and compatibilization of this blend are important as they directly influence the general properties.Transesterification which occurs in the melt state, is a series of cutting and rejoining of dissimilar polymer chains. The reaction ruins the order of pure chains and forms block copolymers of different natures. Further progress in transesterification lead into a completely random copolymer of initial chains. Time, temperature and addition of catalyst can effectively influence transesterification.In this study,... 

    The Effect of Compatibilizer and Short Glass Fiber on Microstructure and Mechanical Properties of PBT/PC Blend

    , M.Sc. Thesis Sharif University of Technology Shahab, Amir Reza (Author) ; Bagheri, Reza (Supervisor)
    Abstract
    In this research, we studied the effect of compatibilizer and short glass fiber on microstructure and mechanical properties of PBT/PC blends. Fisrt, Antioxidants and sodium pyrophosphate dibasic were used to suppress transesterification in PBT/PC Blend. The results showed that best composition occur when both of them are used. In the next step, we used 3%wt MBS (methyl methacrylate-butadiene-styrene) and saw that this weight percent of this compatibilizer doesn’t useful. Moreover addition of short glass fiber to PBT/PC was examined and the results showed that mechanical properties of composite are extensively increased. Also in this step, we proved this idea that we can replace some of PBT... 

    Fabrication of Porous Electrospun Fibe on Biocompatible Polymers such as Polycaprolactone (Pcl) and Thrs Based eir Application in Sample Preparation

    , M.Sc. Thesis Sharif University of Technology Abdi, Parisa (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    The aim of this study was to develop a method to determine the trace residual amounts of nonsteroidal anti-inflammatory drugs in meat-related samples and to study the effect of different cooking methods and storage conditions of meat before cooking as an effective factor on the fate of these drugs. To proceed this goal, a nanocomposite was prepared from polycaprolactone nanofiber/silica mesopores as green sorbent by electrospinning. The synthesized nanocomposite was implemented for micro-solid phase extraction of the desired drugs in conjunction with high performance liquid chromatography. Polycaprolactone, due to its excellent physical properties, availability, biodegradability,... 

    Mechanical Behavior of Recycled Polyethylene Terephthalate/Polycarbonate/Glass Fiber Composites

    , M.Sc. Thesis Sharif University of Technology Haji Rezaei, Mohammad Javad (Author) ; Bagheri, Reza (Supervisor)
    Abstract
    Nowadays, with the increasing number of polyethylene terephthalate wastes, the issue of its recycling has become very important. Among the problems of polyethylene terephthalate recycling are its loss of crystallinity and mechanical properties. Recycled polyethylene terephthalate does not have the properties of new polyethylene terephthalate and using its mixture with other materials is an effective way to remove its waste from nature and return it to the production cycle. The aim of this study is to produce a mixture of recycled polyethylene terephthalate with polycarbonate and glass fibers with mechanical properties such as good impact strength, which ultimately leads to the production of... 

    Synthesis of One-Dimensional Nanoneedle-Like Arrays Hydroxyapatite for Bone Tissue Engineering Applications

    , M.Sc. Thesis Sharif University of Technology Hassanzadeh Chinijani, Turan (Author) ; Nemati, Ali (Supervisor) ; Khachatourian, Adrine Malek (Supervisor) ; Shokri, Babak (Co-Supervisor)
    Abstract
    Implant primary stability is a crucial component of implant survival. Primary mechanical stability is correlated with implant type, surgical technique, quantity and quality of bone at the recipient site. Since bone integration (BI) significance has been acknowledged, a variety of techniques have been developed to quicken BI and achieve faster fixation. Studies have shown that material type, and many surface properties, including as surface composition, roughness, topography, and energy, have a significant influence during the early stages of bone integration to the implant. In this work, we did synthesis one-dimensional nanoneedle-like arrays of hydroxyapatite using the injection method... 

    The potentiostatic electrodeposition of gold nanowire/nanotube in HAuCl4 solutions based on the model of recessed cylindrical ultramicroelectrode array

    , Article Journal of the Electrochemical Society ; Volume 160, Issue 6 , 2013 , Pages D279-D288 ; 00134651 (ISSN) Bagheri Hariri, M ; Dolati, A ; Siavash Moakhar, R ; Sharif University of Technology
    2013
    Abstract
    The mechanism of gold nanowire (AuNW) and nanotube (AuNT) electrodeposition in a cyanide-free solution is investigated for the first time based on the analytical model of Szabo et al. (A. Szabo et al., J. Electroanal. Chem. 217 (1987) 417) for recessed cylindrical ultramicroelectrode (UME). Track-etched Polycarbonate Template (PCT) is served as cylindrical UME ensemble/arrays. Firstly, Au is nucleated through a charge transfer step and when the Nernst thickness exceeds the pore length, the radial diffusion is established around pore mouths. By overlapping of these domains, the planar diffusion toward the whole PCT surface is obtained. An analytic expression for global diffusion coefficient... 

    Electrodeposition of long gold nanotubes in polycarbonate templates as highly sensitive 3D nanoelectrode ensembles

    , Article Electrochimica Acta ; Volume 75 , 2012 , Pages 157-163 ; 00134686 (ISSN) Bahari Mollamahalle, Y ; Ghorbani, M ; Dolati, A ; Sharif University of Technology
    Elsevier  2012
    Abstract
    Electrodeposition of long and well-defined gold nanotubes in polycarbonate (PC) templates is still a major concern due to pore blockage problems. In the present study, we introduce a novel method for electrodeposition of long gold nanotubes within the pores of PC templates for the first time. In order to deposit gold atoms onto the pore walls preferentially, pore walls were functionalized with a coupling agent. Short and thin Ni nanotubes were then electrodeposited at the bottom of the pores. Gold nanotubes were subsequently electrodeposited at constant potentials and low solution concentrations. The morphology of nanotubes was characterized by electron microscopy and their formation... 

    Surface chemistry of atmospheric plasma modified polycarbonate substrates

    , Article Applied Surface Science ; Volume 257, Issue 23 , September , 2011 , Pages 9836-9839 ; 01694332 (ISSN) Yaghoubi, H ; Taghavinia, N ; Sharif University of Technology
    2011
    Abstract
    Surface of polycarbonate substrates were activated by atmospheric plasma torch using different gas pressure, distance from the substrates, velocity of the torch and number of treatments. The modifications were analyzed by contact angle measurements, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and UV-vis spectrophotometry. Plasma treatment caused the surface characteristics to become more hydrophilic as measured by the water contact angle, which decreased from 88° to 18°. The decrease in contact angle was mainly due to oxidation of the surface groups, leading to formation of polar groups with hydrophilic property. XPS results showed an increase in the intensity of... 

    Synthesis and characterization of electrochemically grown CdSe nanowires with enhanced photoconductivity

    , Article Journal of Materials Science: Materials in Electronics ; Volume 26, Issue 3 , March , 2015 , Pages 1395-1402 ; 09574522 (ISSN) Kalhori, H ; Irajizad, A ; Azarian, A ; Ashiri, R ; Sharif University of Technology
    Springer New York LLC  2015
    Abstract
    CdSe nanowires were grown in polycarbonate track etched membrane with pore diameter of 80 nm by an electrochemical deposition technique. The mechanism of the growth was studied during the potentiostatic deposition of nanowires. X-ray photoelectron spectroscopy and energy dispersive spectrometry results showed binding of fragments and fraction of atoms for the CdSe nanowires. Microstructure and morphology of synthesized CdSe nanowires were observed by scanning electron microscopy. Optical spectrophotometry technique was used to determine the energy band gap of CdSe nanowires. It was found that the nanowires were resistive in the dark and exhibited a pronounced visible light photoconductivity.... 

    Electrodeposition of platinum nanowires: Electrochemical characterization

    , Article ECS Transactions, 25 April 2010 through 30 April 2010 ; Volume 28, Issue 18 , April , 2010 , Pages 25-35 ; 19385862 (ISSN) ; 9781607681946 (ISBN) Mahshid, S. S ; Dolati, A ; Hashemi Daryan, S ; Ghorbani, M ; Ghahramaninezhad, A ; Physical and Analytical Electrochemistry ; Sharif University of Technology
    2010
    Abstract
    Platinum nanowires (PtNWs) were electrodeposited on the polycarbonate templates (PCTs) in aqueous solution of H2PtCl6 in triply distilled water. Nanowires with diameters of 50 and 100 nanometers were electrodeposited on the same condition. The kinetics of electrodeposition process was studied by electrochemical techniques such as voltammetry and chronoamperometry methods. Increasing the scan rate, the peaks shifted to more negative potentials and the current density also increased in each peak which was typical for a diffusion-control process. The potential range for the deposition of platinum nanowires was specified and consequently the potentiostatic i-t transients were utilized to produce... 

    A study on the kinetics of gold nanowire electrodeposition in polycarbonate templates

    , Article Journal of Electroanalytical Chemistry ; Volume 645, Issue 1 , June , 2010 , Pages 28-34 ; 15726657 (ISSN) Soleimany, L ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
    2010
    Abstract
    Electrodeposition of gold nanowires is carried out in cyanide solution in polycarbonate templates with pore diameter of 80 nm. Electrochemical methods are utilized to characterize the gold electrodeposition and to obtain the nucleation and growth mechanism. The analysis of cyclic voltammograms shows that the electrodeposition of gold nanowires takes place under diffusion control. Current transients reveal that nucleation mechanism is instantaneous with a three-dimensional growth process. The transition-time measurements show that the gold elecrodeposition occurs as one-electron valence involved in the reaction mechanism. Charge transfer coefficient is also found to be 0.67 ± 0.01. The value... 

    Self cleaning TiO2 coating on polycarbonate: Surface treatment, photocatalytic and nanomechanical properties

    , Article Surface and Coatings Technology ; Volume 204, Issue 9-10 , 2010 , Pages 1562-1568 ; 02578972 (ISSN) Yaghoubi, H ; Taghavinia, N ; Keshavarz Alamdari, E ; Sharif University of Technology
    Abstract
    A developed route to form TiO2 self cleaning coatings on polycarbonate substrates is reported. TiO2 coatings on plastics may find widespread application in auto and construction industries if possess desired photocatalytic and mechanical properties. A chemical surface treatment method was used to create hydrophilic groups on the surface. X-ray photoelectron spectroscopy showed the treatment led to the oxidation of surface groups. TiO2 deposition was based on wet coating using an anatase sol of TiO2 nanoparticles of 30 nm size. The sol was synthesized using a sol-gel route. A pre-coat of peroxotitanium complex was employed to improve adhesion and inhibit the substrate degradation. The coating... 

    Efficient batch-mode mixing and flow patterns in a microfluidic centrifugal platform: a numerical and experimental study

    , Article Microsystem Technologies ; 2016 , Pages 1-13 ; 09467076 (ISSN) Mortazavi, S. M. A ; Tirandazi, P ; Normandie, M ; Saidi, M. S ; Sharif University of Technology
    Springer Verlag 
    Abstract
    During recent years centrifugal-based microfluidic devices known as Lab-on-a-CD have attracted a lot of attentions. Applications of these CD-based platforms are ubiquitous in numerous biological analyses and chemical syntheses. Mixing of different species in microscale is one of the essential operations in biochemical applications where this seemingly simple task remains a major obstruction. Application of centrifugal force, however, may significantly improve the flow agitation and mixing, especially when it is combined with the Coriolis force which acts perpendicular to centrifugal force. In this study, mixing process in minichambers located on a rotating platform under a periodic...