Synthesis of Graphene Oxide and Graphene Oxide Membrane for Separation of Gas Mixtures

Abbasi, Fateme | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48042 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Ghotbi, Sirus; Karimi Sabet, Javad; Mousavi, Abbas
  7. Abstract:
  8. Thin film graphene oxide(GO) membranes have been promising potential for gas purification due to thin lamellar microstructure, stable a few atom thick layers and very short intersheet distances. In this research, the nanoporous graphene oxide membranes have been prepared by vacuum and pressurized ultrafiltration on the modified polyacrylonitryle(mPAN) sublayer for helium separation from Nitrogen and carbon dioxide gas mixture. The separation performance of synthesized GO membrane was controlled by varying parameters such as concentration of stabilized aqueous GO solution, pores size range of support and its surface properties, centrifuge time, applied pressure after synthesis, humidity, methods of drying, the size of graphene oxide sheets, PH of used suspension of graphene oxide, the amount of used graphene oxide in synthesis (0.003 mg/cm2 to 1.556 mg/cm2), synthesis pressure (15, 10, 6 and 2 bar and under vacuum condition), operating pressure (0.083 to 2 bar).In addition to filtration synthesis, other synthesis methods such as drop casting, spin and electrophoresis deposition are studied The properties of graphite oxide by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), GO nano sheets by zeta potential, atomic force microscopy (AFM), morphology of GO membranes by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) have been characterized.The results show that change in the GO solution concentration does not hold a linear relationship with the permeability and selectivity for gas separation mixture. Aggregates, pressure defects and intersheet space have significant influence on the membrane performance. In this study, by tuning operation and synthesis parameters, at operating pressure of 0.083 bar, a selectivity of 8 was achieved through lamellar structure of 0.99 mg/cm2 GO membrane, which synthesized by 10 bar ultrafiltration on the 12% mPAN support
  9. Keywords:
  10. Laminate Structure ; Gases Separation ; Helium Gas ; Graphene Oxide ; Pressurized Ultrafiltration

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