Loading...

Fabrication of Gas Sensor Based on Frequency Shift in Quartz Crystals

Mohammadi Aria, Mohammad | 2013

691 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 45230 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Sarvari, Reza; Irajizad, Azam
  7. Abstract:
  8. In this thesis, gas sensors were fabricated based on resonance frequency shift of quartz crystal with covering of polymer fibers and carbon nanostructure materials.¬ Sensing materials were used in two different types of polyvinylpyrrolidone (PVP) and Graphene oxide. Electrospining was used as an efficient, simple and low cost approach for producing polymer and composite fibers with 280nm to 4um diameters. In addition, the effects of changing various parameters such as the concentration of polymer solution and electrospining process time were investigated. Images taken with a scaning electron microscope indicated that the concentration of polymer solution effectively can affect morphology, diameter and then fibers specific surface area for gas molecules adsorbtion. Also Hummers chemical methode was applied to synthesis graphene oxide sheets without require to any surfactant or stabilizing agent. Dispersed sheets of graphene oxide in suspansion were deposited on the surface of quartz crystal. Then fabricated gas sensors in static set up was tested by exposing to Ethanol, hydrogensulfide and hydrazine. Then sensing responses were used for determination of gas concentration, gas sensing mechanism and interactions between gas molecules and nanostructure materials.The gas sensors showed very good sensitivity to low concentrations (10ppm) of toxic gases such as H2S. Fast response and recovery time and high sensitivity were important properties of fabricated gas sensors. Low manufacturing cost and low power consumption (micro watt) of the gas sensors have made them promising for their industrial development
  9. Keywords:
  10. Quartz Crystal ; Polyvinylpyrolidon ; Electrospinning ; Graphene Oxide

 Digital Object List

 Bookmark

No TOC