Dissertation > Excellent graduate degree dissertation topics show

Synthesis and Gas-Sensing Properties of Polyaniline/Carbon Nanotubes Nanocomposites and P-N Junctions Nanomaterials

Author: HeLiFang
Tutor: LiuJinHuai
School: University of Science and Technology of China
Course: Inorganic Chemistry
Keywords: Carbon nanotubes Polyaniline Ammonia Hollow ball SnO2 CuO doped H2S p-n junction
CLC: TB383.1
Type: Master's thesis
Year: 2009
Downloads: 230
Quote: 1
Read: Download Dissertation

Abstract


With the deepening of the importance of their own health and ecological environment concerns, people put forward higher requirements for monitoring and control of toxic and harmful gases in the environment. The development and application of new gas-sensitive materials on more and more attention, the main body of the gas sensor. Nanomaterials has attracted widespread attention because of its special structure and properties, while a large study found that the potential applications of nanomaterials in sensor. It inspired the paper do the work of the following two aspects: (1) In this paper, a relatively simple and low-cost method to prepare polyaniline (PANI) wrapped MWNTs nanocomposite sensor on this basis for the first time the gas sensing performance nanocomposite systems different PANI parcel layer thickness on the gas sensitivity. The carbon nanotubes as sensor materials such as low sensitivity, select, and a long recovery time and other shortcomings. In order to improve the sensing properties of carbon nanotubes with a simple in situ polymerization of MWNTs wrapped modification, PANI coated multi-walled carbon nanotube composites. Morphology characterization of composite materials that PANI uniformly wrapped in the surface of carbon nanotubes to form a film, and the thickness of the film can tune Results amount of the aniline monomer to control. The gas-sensitive test results show that the composite material has a high sensitivity and good reproducibility NH 3 , and the concentration in the range of 0.2-15ppm NH 3 linearly sexual response. Respectively, and compared to the pure carbon nanotubes as well as pure polyaniline nanocomposites NH 3 sensitivity has been significantly improved, and the response time is significantly shorter. On the other hand, in order to get a relatively better gas sensing properties of material, we also studied the different thickness of the PANI wrapped layer of gas-sensing properties of composite materials. (2) of the hollow nanospheres material gas sensing performance improvements, we get a new nanocomposites with high gas sensing performance-CuO-doped SnO 2 nano hollow sphere material. The present study indicate that the the SnO 2 hollow nanospheres material is a promising sensor material. But a lot of gas response, selectivity, which to some extent limit the application of the material. In order to improve the selectivity of the material gas sensing, we try to and its oxide doped improved. First, using relatively simpler method of synthesis of SnO 2 Hollow ball material, then through the infiltration of the precursor solution of copper, and finally calcined doped CuO of SnO 2 hollow nanospheres material to study further its structure and gas sensitive properties were investigated. Gas sensing test: of CuO-doped SnO 2 hollow nanospheres material 10 ppm H reached 5.6 × 10 6 2 S sensitivity in the low temperatures of 35oC , and ppb level H 2 S gas response. Compared to pure SnO 2 hollow nanospheres material after CuO doped composites significantly improve the selectivity and sensitivity of H 2 S gas. The experimental results show that the nano-composite materials in the trace H 2 S gas monitoring potential applications. Excellent sensing properties of CuO doped SnO 2 hollow nanospheres material due to the pn junction formation, and the presence of the hollow spherical structure. This study further proved hollow spherical structure of nanomaterials is a promising sensor material.

Related Dissertations

  1. Research on Fabrication Technology of A-Si:H/c-Si Hetero-Junction Solar Cells,TM914.4
  2. Thermal studies of high - power LED devices,TN312.8
  3. Research on Miniaturized Folded Waveguide Power Dividers,TN626
  4. Theory Modeling and Analysis of Precision CNC Lathe,TG519.1
  5. The Clinical Observation of Warm-Needleacupunc-Ture Acupuncturing the Meridian Sinew Nodal point to Treat the Low Moderate Capal Tunne Syndrome,R246
  6. Clinical Observation on Treatment to Spastic Paralysis after Stroke by Acupuncture Meridian Sinew Nodal Point with Intermediate Frequency with Intermediate Frequency Medicine Induction,R246
  7. High isoflavone content of soy transferred gene callus,R284
  8. Research of Immune Status of 117 Cases of Shi Re Yu Jie Chronic Pelvic Inflammatory Disease,R271.9
  9. Feedthrough structure transistor simulation analysis BV_ (CEO) and consistency to improve research,TN322.8
  10. Design and Fabrication of 2μm Bipolar Cascade Laser,TN248
  11. Research on Tunneling Magneto Resistance with Time-dependent Double-delta Barrier,O482.5
  12. The Combination of Acupuncture Bobath Therapy Tendon Junction of Spastic Paralysis after Stroke Clinical Efficacy,R246
  13. The circulator Used BaFe_ (12) O_ (19) thick film preparation and application of,O614.233
  14. Possible Role of Gap Junction Channels Changed in Experimental Subarachnoid Hemorrhage Cerebral Vasospasm Models,R743.3
  15. The Effects of Connexin 43 Phosphorylation on Cerebral Vasospasm,R743.3
  16. Design and Implementation of FPGA- TS201 link port data transmission system,TN919.6
  17. By using a stepped -doped buried layer on ultra- shallow junction bilateral CV profile analysis,TN386.1
  18. Urban traffic signal intelligent control system design and simulation,TP273.5
  19. Research High-sensitivity TVS,TN312.8
  20. High-power LED lamps cooling system design and research,TM923.34
  21. Small five-axis CNC machine tool design evaluation and structural dynamic analysis,TG659

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net  Mobile