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Modification of Electrospun Nanofibers Towards Sorbents with Higher Aspect Ratio

Najarzadekan, Hamid | 2013

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 44833 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagheri, Habib
  7. Abstract:
  8. In this study, a novel electrospun modified polyamide (PA) based nanofibers were synthesized and employed as fibers coating for rapid determination of chlorophenols. The major polymer solution contained PA along with polyethylene glycol (PEG), acting as a side low molecular weight polymer. After production of the PA−PEG fiber coating, PEG was subsequently removed and modified by water which was confirmed by Fourier transform infra-red spectrometry.The scanning electron microscopy images showed anaverage diameter of 640 and 148 nmforPA and PA−PEG coatings, respectively while the latter coating structure was homogeneous and porous.The extraction efficiency of unmodified and modified coatings was investigated by headspace solid phase microextraction(HS−SPME) of some environmentally important chlorophenols from aqueous samplesfollowed by gaschromatography-flame ionization detector determination.The effect of added amounts of PEG to the main PA constituent and the flow rate of electrospinnig solution were assayed. Moreover, effects of different parameters influencing theextraction efficiency including the ionic strength, desorption temperature and time, extraction temperature and time were optimized.Eventually, the developed method was validated by gas chromatography−mass spectrometry.The detection limits of the method under optimized conditions were in the range of 0.8−25 ng L−1. The relativestandard deviations (RSD %) at the concentration level of 200 ng L−1and 80 ng L-1 were between 2.1 and 12.2%. The calibration curves of chlorophenols showed linearity in the range of 8−1500 ng L-1. The developedmethod was successfully applied to the extraction of phenol and chlorophenols from real watersamples and relative recoveries were between 85 and 98% for all the selected analytes
  9. Keywords:
  10. Solid Phase Microextraction ; Polyethylen Glycol (PEG) ; Electrospinning ; Gas Chromatography/Mass Spectrometry (GC/MS) ; Chlorophenols ; Modified Polyamide Nanofiber

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