Search for: silicones
Total 531 records
pH and thermal dual-responsive poly(NIPAM-co-GMA)-coated magnetic nanoparticles via surface-initiated RAFT polymerization for controlled drug delivery, Article Materials Science and Engineering C ; Volume 108 , 2020 ; Kohestanian, M ; Streb, C ; Sharif University of Technology
Elsevier Ltd 2020
Herein, a novel type of multifunctional magnetic nanoparticles with dual thermal and pH-responsive behavior was fabricated as the carrier for delivery of doxorubicin (DOX). Fe3O4@SiO2 magnetic nanoparticles, were grafted with polymer brushes consisting of poly (NIPAM-co-GMA) (PNG) chains via surface initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization. The polymer brushes were then modified with hydrazine groups as DOX binding sites. The prepared multifunctional magnetic nanoparticles were characterized by FT-IR, 1H NMR, XPS, TGA, DLS, VSM, GPC, TEM, and XRD analysis. The in vitro drug release of the multifunctional magnetic nanoparticles was examined at 37 °C...
Ag-doped magnetic metal organic framework as a novel nanostructured material for highly efficient antibacterial activity, Article Environmental Research ; Volume 188 , 2020 ; Abdi, J ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
Academic Press Inc 2020
In the last decades, numerous attempts have been made to prevent microbial pollution spreading, using antibacterial agents. Zeolitic imidazolate framework-8 (ZIF-8) belongs to a subgroup of metal organic frameworks (MOFs) merits of attention due to the zinc ion clusters and its effective antibacterial activity. In this work, Ag-doped magnetic microporous γ-Fe2O3@SiO2@ZIF-8-Ag (FSZ-Ag) was successfully synthesized by a facile methodology in room temperature and used as an antibacterial agent against the growth of the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Several characterization methods were applied to analyze the properties of the materials, and the...
Design of an effective piezoelectric microcantilever biosensor for rapid detection of COVID-19, Article Journal of Medical Engineering and Technology ; Volume 45, Issue 6 , 2021 , Pages 423-433 ; 03091902 (ISSN) ; Merati, M ; Abdekhodaie, M. J ; Sharif University of Technology
Taylor and Francis Ltd 2021
Acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also called COVID-19, is one of the most contagious viruses resulting in a progressive pandemic. Since specific antiviral treatments have not been developed yet and its fatal rate is almost high, early and fast detection is critical for controlling the outbreak. In this study, a piezoelectric microcantilever biosensor has been designed for detecting COVID-19 samples directly without requiring preparation steps. The biosensor acts as a transducer and is coated with the related antibody. When the SARS-CoV-2 antigens adsorbed on the microcantilever top surface through their spike proteins, a surface stress due to the mass change would be...
Aniline-silica nanocomposite as a novel solid phase microextraction fiber coating, Article Journal of Chromatography A ; Volume 1238 , May , 2012 , Pages 22-29 ; 00219673 (ISSN) ; Roostaie, A ; Sharif University of Technology
A new unbreakable solid phase microextraction (SPME) fiber coating based on aniline-silica nanocomposite was electrodeposited on a stainless steel wire. The electropolymerization process was carried out at a constant deposition potential, applied to the corresponding aqueous electrolyte containing aniline and silica nanoparticles. The scanning electron microscopy (SEM) images showed the non-smooth and the porous surface structure of the prepared nanocomposite. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some environmentally important polycyclic aromatic hydrocarbons (PAHs), as model compounds, from aqueous samples....
Novel unbreakable solid-phase microextraction fiber by electrodeposition of silica sol-gel on gold, Article Journal of Separation Science ; Volume 34, Issue 22 , 2011 , Pages 3246-3252 ; 16159306 (ISSN) ; Sistani, H ; Ayazi, Z ; Sharif University of Technology
A new technique for preparation of an unbreakable solid-phase microextraction (SPME) fiber, using sol-gel technology is developed. Primarily, an ultrathin two-dimensional intermediate film was prepared by hydrolysis of 3-(trimethoxysilyl)-1-propanthiol self-assembled monolayer grafted onto gold, then a stationary phase by electrodeposition of 3-(trimethoxysilyl) propylmethacrylate as a precursor, tetramethyl orthosilicate and polyethylene glycol as a coating polymer was produced. The scanning electron microscopy images revealed that the new fiber exhibits a rather porous and homogenous surface. The thermal stability of the fabricated fiber was investigated by thermogravimetric analysis. The...
Synthesis of some new 1,4-distyrylbenzenes using immobilized palladium nanoparticles on silica functionalized morpholine as a recyclable catalyst, Article Synthesis ; Issue 10 , 2011 , Pages 1609-1615 ; 00397881 (ISSN) ; Gharavi, A ; Nezhad, M. R. H ; Panahi, F ; Sharbati, M. T ; Sharif University of Technology
Some new 1,4-distyrylbenzene derivatives were synthesized by using immobilized palladium nanoparticles on silica-bonded N-propyl morpholine (PNP-SBNPM) as a heterogeneous catalyst. These one-pot reactions afforded a range of stereoselective, symmetrical (E)-1,4-distyrylbenzene derivatives with high yields (78-90%). The green catalyst system is recyclable and allows facile product isolation. The recycled catalyst could be reused six times without appreciable loss of catalytic activity
A novel needle trap sorbent based on carbon nanotube-sol-gel for microextraction of polycyclic aromatic hydrocarbons from aquatic media, Article Analytica Chimica Acta ; Volume 683, Issue 2 , January , 2011 , Pages 212-220 ; 00032670 (ISSN) ; Ayazi, Z ; Aghakhani, A ; Sharif University of Technology
A new type of composite material based on carbon nanotubes (CNTs) and sol-gel chemistry was prepared and used as sorbent for needle trap device (NTD). The synthesized composite was prepared in a way to disperse CNTs molecules in a sol-gel polymeric network. CNT/silica composites with different CNT doping levels were successfully prepared, and the extraction capability of each composite was evaluated. Effects of surfactant and the oxidation duration of CNTs on the extraction efficiency of synthesized composites were also investigated. The applicability of the synthesized sorbent was examined by developing a method based on needle trap extraction (NTE) and gas chromatography mass spectrometry...
In situ synthesis of nanocrystalline Al6063 matrix nanocomposite powder via reactive mechanical alloying, Article Materials Science and Engineering A ; Volume 527, Issue 18-19 , 2010 , Pages 4897-4905 ; 09215093 (ISSN) ; Simchi, A ; Kim, H. S ; Sharif University of Technology
In this work, nanocrystalline Al6063 composite powder reinforced with nanometric oxide ceramic particles was synthesized via an in situ solid-gas reaction during high-energy mechanical alloying under a mixture of argon-oxygen atmosphere. The effect of oxygen volume fraction on the morphological evolution and microstructural changes during mechanical alloying was studied by various analytical techniques including optical and electron microscopy, X-ray diffraction, laser particle size analysis, apparent density measurement, and microhardness test. The reactive mechanical alloying resulted in the formation of amorphous Al- and Al-Mg-Si-Fe oxides with a size range of 40-100. nm and volume...
Silica aerogel coated on metallic wire by phase separation of polystyrene for in–tube solid phase microextraction, Article Journal of Chromatography A ; Volume 1500 , 2017 , Pages 69-75 ; 00219673 (ISSN) ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2017
In this research, an attempt was made toward synthesizing a sol–gel–based silica aerogel and its subsequent coating on a copper wire by phase separation of polystyrene. Adaption of this new approach enabled us to coat the metallic wire with powder materials. The use of this method for coating, led to the formation of a porous and thick structure of silica aerogel. The coated wire was placed in a needle and used as the sorbent for in–tube solid phase microextraction of chlorobenzenes (CBs). The superhydrophobicity of sorbent on extraction efficiency was investigated by using different ratios of tetraethylorthosilicate/methyltrimethoxysilane. The surface coated with the prepared silica aerogel...
Immobilization of synthesized phenyl-enriched magnetic nanoparticles in a fabricated Y–Y shaped micro-channel containing microscaled hedges as a microextraction platform, Article Analytica Chimica Acta ; Volume 1136 , 2020 , Pages 51-61 ; Hedeshi, M. H ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2020
In this survey, a reliable and applicable Y–Y shaped micro–channel in a microfluidic device was designed and manufactured. A number of micro–scaled hedges were precisely fabricated inside the micro–channel to facilitate the immobilization of synthesized core–shell Fe3O4@SiO2 magnetic nanoparticles (MNPs), functionalized by triethoxyphenylsilane (TEPS) by sol-gel technique. Both sample and reagents were introduced into the microfluidic device by a syringe pump to perform the extraction and desorption steps. The functionalized MNPs were characterized by transmission electron microscopy, X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy. By adopting the strategy of...
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
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...