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Electrospun Nanofibers and Their Application for Microextraction of Environmental Samples

Aghakhani, Ali | 2011

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 42150 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagheri, Habib
  7. Abstract:
  8. Novel electrospun nanofibers and their applications as the microextractionsorbents are the centre of this research. Polymeric nanofibers with diameter in the scale of nano-to-micro were prepared by the electrospinning method and employed for microextraction purposes. Two major microextraction methods included solid phase microextraction (SPME) and micro-Solid phase extraction (µ-SPE). In the first work, a novel SPME fiber was fabricated by electrospinning method. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100–200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography–mass spectrometry (GC–MS) analysis. The detection limits of the method under optimized conditions were in the range of 2–10 ng L−1. In the second work, 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 GC-MS analysis. Among them, PU showed a prominent efficiency. The SEM images of the PU coating showed a diameter range of 150–600 nm with a homogeneous and porous surface structure. The limits of detection and quantification of the method under optimized conditions were 10 and 50 ng L-1, respectively. The calibration curves of CBs showed linearity from 50 to1000 ng L-1.

  9. Keywords:
  10. Electrospinning ; Solid Phase Microextraction ; Gas Chromatography/Mass Spectrometry (GC/MS) ; Polymeric Nanofiber ; Micro-Solid Phase Extraction

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