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fiber-coatings
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Determination of the scattered fields of an SH-wave by an eccentric coating-fiber ensemble using DEIM
, Article International Journal of Engineering Science ; Volume 46, Issue 11 , 2008 , Pages 1136-1146 ; 00207225 (ISSN) ; Mohammadi Shodja, H ; Delfani, M. R ; Sharif University of Technology
2008
Abstract
To date, the existing theories pertinent to the determination of the scattered fields of an inhomogeneity have been limited to certain topological symmetries for which the method of wave-function expansion is widely used. In the literature the wave-function expansion method has also been employed to the case involving concentric coated fiber. An alternative approach is the dynamic equivalent inclusion method (DEIM) proposed by Fu and Mura [L.S. Fu, T. Mura, The determination of elastodynamic fields of an ellipsoidal inhomogeneity. ASME J. Appl. Mech. 50 (1983) 390-396.] who found the scattered field of a single spheroidal inhomogeneity. The pioneering work of Eshelby [J.D. Eshelby, The...
Investigation of interfacial and mechanical properties of alumina-coated steel fiber reinforced geopolymer composites
, Article Construction and Building Materials ; Volume 288 , 2021 ; 09500618 (ISSN) ; Nemati, A ; Khodabandeh, A. R ; Baghshahi, S ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this study, alumina coated steel reinforced geopolymer composites were successfully fabricated and their interfacial and mechanical properties were investigated. The fiber–matrix interface characteristics were assessed using single-fiber push-out and water contact angle experiments as well as SEM-EDS analysis. Finally, the role of alumina coating on the compressive, flexural and toughness of the geopolymer composites was investigated. The morphological studies revealed that alumina coating on steel can chemically bonded and microstructurally integrated with the surrounding matrix. The push-out test showed that the interfacial shear strength was increased approximately 150% in composites...
An aniline-based fiber coating for solid phase microextraction of polycyclic aromatic hydrocarbons from water followed by gas chromatography-mass spectrometry
, Article Journal of Chromatography A ; Volume 1152, Issue 1-2 , 2007 , Pages 168-174 ; 00219673 (ISSN) ; Babanezhad, E ; Eshaghi, A ; Sharif University of Technology
2007
Abstract
A fiber coating from polyaniline (PANI) was electrochemically prepared and employed for solid phase microextraction (SPME) of some polycyclic aromatic hydrocarbons (PAHs) from water samples. The PANI film was directly electrodeposited on the platinum wire surface in sulfuric acid solution using cyclic voltammetry (CV) technique. The applicability of this coating was assessed employing a laboratory-made SPME device and gas chromatography with mass spectrometry (GC-MS) for the extraction of some PAHs from the headspace of aqueous samples. Application of wider potential range in CV led to a PANI with more stability against the temperature. The homogeneity and the porous surface structure of the...
Towards greater mechanical, thermal and chemical stability in solid-phase microextraction
, Article TrAC - Trends in Analytical Chemistry ; Volume 34 , 2012 , Pages 126-138 ; 01659936 (ISSN) ; Piri-Moghadam, H ; Naderi, M ; Sharif University of Technology
Abstract
Solid-phase microextraction (SPME) is a fast, solvent-free technique, which, since its introduction in the 1990s, has been increasingly applied to sample preparation in analytical chemistry. Conventional SPME fibers are fabricated by making a physical bond between the usual silica substrate and the polymeric coatings. However, some applications are limited, as the lifetime and the stability of conventional SPME fibers cannot meet the demands of analyzing relatively non-volatile compounds with more polar moieties. There have been attempts to analyze less volatile compounds by increasing the thermal, physical and chemical stability of the fibers. In this review, we present some new...
Novel nanofiber coatings prepared by electrospinning technique for headspace solid-phase microextraction of chlorobenzenes from environmental samples
, Article Analytical Methods ; Volume 3, Issue 6 , Apr , 2011 , Pages 1284-1289 ; 17599660 (ISSN) ; Aghakhani, A ; Sharif University of Technology
2011
Abstract
Novel unbreakable solid phase microextraction (SPME) fiber coatings were fabricated by electrospinning method in which the polymeric solution was converted to nanofibers using high voltages. Four different polymers, polyurethane (PU), polycarbonate (PC), polyamide (PA) and polyvinyl chloride (PVC) were prepared as the fiber coatings on thin stainless steel wires. The extraction efficiencies of new coatings were investigated by headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorobenzenes from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Among them, PU showed a prominent efficiency. Effects of coating time and polymer...
Role of precursors and coating polymers in sol-gel chemistry toward enhanced selectivity and efficiency in solid phase microextraction
, Article Analytica Chimica Acta ; Volume 742 , 2012 , Pages 45-53 ; 00032670 (ISSN) ; Piri Moghadam, H ; Ahdi, T ; Sharif University of Technology
Elsevier
2012
Abstract
To evaluate the selectivity and efficiency of solid phase microextraction (SPME) fiber coatings, synthesized by sol-gel technology, roles of precursors and coating polymers were extensively investigated. An on-line combination of capillary microextraction (CME) technique and high performance liquid chromatography (HPLC) was set up to perform the investigation. Ten different fiber coatings were synthesized in which five of them contained only the precursor and the rests were prepared using both the precursor and coating polymer. All the coatings were chemically bonded to the inner surface of copper tubes, intended to be used as the CME device and already functionalized by self-assembly...
In situ solid-phase microextraction and post on-fiber derivatization combined with gas chromatography-mass spectrometry for determination of phenol in occupational air
, Article Analytica Chimica Acta ; Volume 742 , 2012 , Pages 17-21 ; 00032670 (ISSN) ; Baghernejad, M ; Bagheri, H ; Sharif University of Technology
Elsevier
2012
Abstract
A method based on solid-phase microextraction (SPME) followed by on-fiber derivatization and gas chromatography-mass spectrometry detection (GC-MS) for determination of phenol in air was developed. Three different types of SPME fibers, polar and non-polar poly(dimethylsiloxane) (PDMS) and polyethylene glycol (PEG) were synthesized using sol-gel technology and their feasibility to the sampling of phenol were investigated. Different derivatization reagents for post on-fiber derivatization of phenol were studied. Important parameters influencing the extraction and derivatization process such as type of fiber coating, type and volume of derivatizing reagent, derivatization time and temperature,...
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
2012
Abstract
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
Abstract
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...
A metal organic framework-polyaniline nanocomposite as a fiber coating for solid phase microextraction
, Article Journal of Chromatography A ; Volume 1431 , 2016 , Pages 27-35 ; 00219673 (ISSN) ; Javanmardi, H ; Abbasi, A ; Banihashemi, S ; Sharif University of Technology
Elsevier B. V
Abstract
A metal organic framework-polyaniline (MOF/PANI) nanocomposite was electrodeposited on a stainless steel wire and used as a solid phase microextraction (SPME) fiber coating. The electropolymerization process was carried out under a constant deposition potential and applied to the corresponding aqueous electrolyte containing aniline and MOF particles. The employment of MOFs with their large and small cages and 3-D structures in synthesizing a nanocomposite was assumed to be efficient constitutes to induce more non-smooth and porous structures, approved by scanning electron microscopy (SEM) images. Three different MOFs were incorporated to synthesize the desired nanocomposites and the...