Nanofiber mats conductivity sensors

Figure 14.6 Sensing ofHCI and NH3 using PPy/carbon nanofiber composites (a) SEM image of the nanofiber mat and (b) TEM of a single composite nanofibers (c) responses of the composite nanocables (a and b) and bulk PPy (c and d) to NHj (a and c) and HC (b and d) (Reprinted with permission from Sensors and Actuators B Chemical, CO gas sensing from ultrathin nano-composite conducting polymer film byM. K. Ram, O. Yavuz, f. Lahsangah and M. Aldissi, 106, 2, 750-757. Copyright (2005) Elsevier Ltd)...

The vapor phase chemical deposition of PPy on the surface of the electrospun PVA nanofibers was successfully performed. Morphology of the nanofibers and successful deposition of the PPy onto the nanofibers is governed by the oxidant type and its concentration in the electrospinning solution. At the best studied condition, a layer of PPy with the thickness of 1,000 nm is formed onto the PVA nanofibers surface using ammonium persulfate as oxidant. In contrast, surface coating was not observed in the case of FeClj as oxidant. The electrical conductivity of the coated nanofiber mats depends on the coating conditions and reaches to 10 S/cm. Large surface area of the sensor material with the electrochemical activity is one of the most important properties for sensor application. Since, it is obvious that the surface area of PPy coated non-... 

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