Search for: dimethylpolysiloxanes
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    Sol-gel-based solid-phase microextraction and gas chromatography-mass spectrometry determination of dextromethorphan and dextrorphan in human plasma

    , Article Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences ; Volume 818, Issue 2 , 2005 , Pages 147-157 ; 15700232 (ISSN) Bagheri, H ; Eshaghi, A ; Rouini, M. R ; Sharif University of Technology
    A novel solid-phase microextraction (SPME) method was developed for isolation of dextromethorphan (DM) and its main metabolite dextrorphan (DP) from human plasma followed by GC-MS determination. Three different polymers, poly(dimethylsiloxane) (PDMS), poly(ethylenepropyleneglycol) monobutyl ether (Ucon) and polyethylene glycol (PEG) were synthesized as coated fibers using sol-gel methodologies. DP was converted to its acetyl-derivative prior to extraction and subsequent determination. The porosity of coated fibers was examined by SEM technique. Effects of different parameters such as fiber coating type, extraction mode, agitation method, sample volume, extraction time, and desorption... 

    Fabrication and characterization of low-cost, bead-free, durable and hydrophobic electrospun membrane for 3D cell culture

    , Article Biomedical Microdevices ; Volume 19, Issue 4 , 2017 ; 13872176 (ISSN) Moghadas, H ; Saidi, M. S ; Kashaninejad, N ; Kiyoumarsioskouei, A ; Trung Nguyen, N ; Sharif University of Technology
    This paper reports the fabrication of electrospun polydimethylsiloxane (PDMS) membranes/scaffolds that are suitable for three-dimensional (3D) cell culture. Through modification the ratio between PDMS and polymethylmethacrylate (PMMA) as carrier polymer, we report the possibility of increasing PDMS weight ratio of up to 6 for electrospinning. Increasing the PDMS content increases the fiber diameter, the pore size, and the hydrophobicity. To our best knowledge, this is the first report describing beads-free, durable and portable electrospun membrane with maximum content of PDMS suitable for cell culture applications. To show the proof-of-concept, we successfully cultured epithelial lung... 

    A novel sol-gel-based amino-functionalized fiber for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples

    , Article Analytica Chimica Acta ; Volume 616, Issue 1 , 2008 , Pages 49-55 ; 00032670 (ISSN) Bagheri, H ; Babanezhad, E ; Khalilian, F ; Sharif University of Technology
    A novel amino-functionalized polymer was synthesized using 3-(trimethoxysilyl) propyl amine (TMSPA) as precursor and hydroxy-terminated polydimethylsiloxane (OH-PDMS) by sol-gel technology and coated on fused-silica fiber. The synthesis was designed in a way to impart polar moiety into the coating network. The scanning electron microscopy (SEM) images of this new coating showed the homogeneity and the porous surface structure of the film. The efficiency of new coating was investigated for headspace solid-phase microextraction (SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different... 

    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) Es haghi, A ; Baghernejad, M ; Bagheri, H ; Sharif University of Technology
    Elsevier  2012
    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,...