Search for: polycarbonate
0.012 seconds
Total 35 records

    Field emission of Co nanowires in polycarbonate template

    , Article Thin Solid Films ; Volume 517, Issue 5 , 1 January , 2009 , Pages 1736-1739 ; 00406090 (ISSN) Azarian, A ; Iraji Zad, A ; Dolati, A ; Mahdavi, S. M ; Sharif University of Technology
    The Co nanowire arrays were synthesized by electrodeposition in polycarbonate template (PC) with 4 μm thickness. Electron field emission properties of cobalt nanowires were studied for wires with different aspect ratios, R ranged between 10 and 60, while the diameter of wires was fixed about 50 nm. The field emission properties of the samples showed low turn on electric field (Eto) with values varying between 2.9 and 11.3 V/μm showing a minimum value for R = 20 (Eto < 3 V/μm). On the other hand, the enhancement factor shows a peak for nanowires length about 1 μm. Field emission data using the Fowler-Nordhiem theory showed nearly straight-line nature confirming cold field emission of... 

    Friction stir welding of polycarbonate lap joints: Relationship between processing parameters and mechanical properties

    , Article Polymer Testing ; Volume 79 , 2019 ; 01429418 (ISSN) Aghajani Derazkola, H ; Simchi, A ; Lambiase, F ; Sharif University of Technology
    Elsevier Ltd  2019
    The relation between process parameters and properties of polycarbonate (PC) sheet after friction stir welding (FSW) was investigated. Effects of FSW tool rotation speed (ω), travelling speed (V), tilt angle (α) and plunge depth on material flow, joint tensile strength, flexural strength, impact energy and hardness were investigated. It is shown that at low and high levels of heat input sound joints cannot be attained. At low heat inputs, the local temperature is not high enough to decrease the viscosity of the polymer to fill the interface, and thus voids and large planar cracks are formed in the joint root and stir zone. At high heat inputs, expelling of materials due to high peak... 

    An ultrasensitive label free human papilloma virus DNA biosensor using gold nanotubes based on nanoporous polycarbonate in electrical alignment

    , Article Analytica Chimica Acta ; Volume 1048 , 2019 , Pages 31-41 ; 00032670 (ISSN) Shariati, M ; Ghorbani, M ; Sasanpour, P ; Karimizefreh, A ; Sharif University of Technology
    Elsevier B.V  2019
    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... 

    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)
    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... 

    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)
    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)
    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,... 

    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
    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.... 

    Modeling and experimental validation of material flow during FSW of polycarbonate

    , Article Materials Today Communications ; Volume 22 , 2020 Derazkola, H. A ; Eyvazian, A ; Simchi, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Friction stir welding (FSW) of thermoplastic materials is an attractive but a challenging process due to inherent chemical and mechanical characteristics of polymeric materials. In the present work, thermo-mechanical models were employed to investigate the effect of processing parameters on of FSW of polycarbonate (PC). The heat flux during the joining process was localized around the PC join line and led to the formation of circular rings on the upper surface. According to the simulation results, increasing the tool rotational velocity reduced the temperature gradient and decfeased the suseptibelity of crack formation around the joint line. Cracks were formed at low frictional heats and... 

    Polycarbonate surface cell's adhesion examination after Nd:YAG laser irradiation

    , Article Materials Science and Engineering C ; Volume 29, Issue 4 , 2009 , Pages 1491-1497 ; 09284931 (ISSN) Ramezani Saadat Abadi, A ; Mousavi, A ; Seyedjafari, E ; Poursalehi, R ; Sareh, S ; Silakhori, K ; Poorfatollah, A. A ; Shamkhali, A. N ; Sharif University of Technology
    Nd:YAG laser treatment was used in order to increase surface cell adhesion aspects of polycarbonate (PC) films prepared via melt process. The treatment was carried out under different wavelengths and beam diameters. ATR-FTIR and UV spectra obtained from different samples before and after laser treatment in air showed that laser irradiation has induced some chemical and physical changes in surface properties. The irradiated films were also characterized using scanning electron microscopy (SEM) and contact angle measurements. Effect of pulse numbers on the surface properties was also investigated. Cell culture test was used to evaluate cell adhesion property on the PC films before and after... 

    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
    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... 

    Surface plasmon resonance of two-segmented Au-Cu nanorods

    , Article Nanotechnology ; Volume 19, Issue 41 , 2008 ; 09574484 (ISSN) Azarian, A ; Iraji Zad, A ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
    Two-segmented gold-copper nanorods were electrodeposited inside the pores of polycarbonate track-etched membranes from two separate solutions. The PCT membranes were dissolved in dichloromethane (CH2Cl2) and the solvent was replaced by methanol solution. Optical absorption spectra of two-segmented Au-Cu nanorods dispersed in methanol showed two peaks which were related to the transverse mode of copper and the longitudinal mode of gold. By increasing the length of the gold segment, when the total length of both metals was fixed at 1 μm, the copper and gold peaks shifted to the blue and red wavelengths, respectively. We observed that the wavelengths of the extinction peaks are not in good... 

    Nanotechnology-assisted microfluidic systems: From bench to bedside

    , Article Nanomedicine ; Volume 16, Issue 3 , 2021 , Pages 237-258 ; 17435889 (ISSN) Rabiee, N ; Ahmadi, S ; Fatahi, Y ; Rabiee, M ; Bagherzadeh, M ; Dinarvand, R ; Bagheri, B ; Zarrintaj, P ; Saeb, M. R ; Webster, T. J ; Sharif University of Technology
    Future Medicine Ltd  2021
    With significant advancements in research technologies, and an increasing global population, microfluidic and nanofluidic systems (such as point-of-care, lab-on-a-chip, organ-on-a-chip, etc) have started to revolutionize medicine. Devices that combine micron and nanotechnologies have increased sensitivity, precision and versatility for numerous medical applications. However, while there has been extensive research on microfluidic and nanofluidic systems, very few have experienced wide-spread commercialization which is puzzling and deserves our collective attention. For the above reasons, in this article, we review research advances that combine micro and nanotechnologies to create the next... 

    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
    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... 

    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
    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... 

    Gut-on-a-chip: Current progress and future opportunities

    , Article Biomaterials ; Volume 255 , 2020 Ashammakhi, N ; Nasiri, R ; Barros, N. R. D ; Tebon, P ; Thakor, J ; Goudie, M ; Shamloo, A ; Martin, M. G ; Khademhosseni, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Organ-on-a-chip technology tries to mimic the complexity of native tissues in vitro. Important progress has recently been made in using this technology to study the gut with and without microbiota. These in vitro models can serve as an alternative to animal models for studying physiology, pathology, and pharmacology. While these models have greater physiological relevance than two-dimensional (2D) cell systems in vitro, endocrine and immunological functions in gut-on-a-chip models are still poorly represented. Furthermore, the construction of complex models, in which different cell types and structures interact, remains a challenge. Generally, gut-on-a-chip models have the potential to...