Limits...
Gas Sensors Based on Conducting Polymers

View Article: PubMed Central

ABSTRACT

The gas sensors fabricated by using conducting polymers such as polyaniline (PAni), polypyrrole (PPy) and poly (3,4-ethylenedioxythiophene) (PEDOT) as the active layers have been reviewed. This review discusses the sensing mechanism and configurations of the sensors. The factors that affect the performances of the gas sensors are also addressed. The disadvantages of the sensors and a brief prospect in this research field are discussed at the end of the review.

No MeSH data available.


Equivalent circuit diagram of the device shown in Figure 3.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3756721&req=5

f5-sensors-07-00267: Equivalent circuit diagram of the device shown in Figure 3.

Mentions: An equivalent circuit diagram is presented in Figure 5 [130, 131]. The change in any parts of the sensor will cause a consequential change of overall resistance of the device. Of course, the most important part is the bulk resistance. For a doped conducting polymer, its conductivity consists of three component:1σ=1σc+1σh+1σiwhere σ is overall conductivity, σc the intermolecular conductivity, σh the intramolecular hopping conductivity and σi the ionic conductivity, respectively. According to the description in 3.1, when react with analytes, σc can be altered by changing doping levels of conducting polymers by both redox and acidic/basic doping/dedoping. σh is usually modulated through adjusting intrachain distance of polymer chains. This is achieved by swelling the polymer, changing crystallinity, forming H-bonds and dipolar-dipolar interactions. σI is controlled by mobility of counter ions, which is effected by the interaction between the ions and analytes.


Gas Sensors Based on Conducting Polymers
Equivalent circuit diagram of the device shown in Figure 3.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756721&req=5

f5-sensors-07-00267: Equivalent circuit diagram of the device shown in Figure 3.
Mentions: An equivalent circuit diagram is presented in Figure 5 [130, 131]. The change in any parts of the sensor will cause a consequential change of overall resistance of the device. Of course, the most important part is the bulk resistance. For a doped conducting polymer, its conductivity consists of three component:1σ=1σc+1σh+1σiwhere σ is overall conductivity, σc the intermolecular conductivity, σh the intramolecular hopping conductivity and σi the ionic conductivity, respectively. According to the description in 3.1, when react with analytes, σc can be altered by changing doping levels of conducting polymers by both redox and acidic/basic doping/dedoping. σh is usually modulated through adjusting intrachain distance of polymer chains. This is achieved by swelling the polymer, changing crystallinity, forming H-bonds and dipolar-dipolar interactions. σI is controlled by mobility of counter ions, which is effected by the interaction between the ions and analytes.

View Article: PubMed Central

ABSTRACT

The gas sensors fabricated by using conducting polymers such as polyaniline (PAni), polypyrrole (PPy) and poly (3,4-ethylenedioxythiophene) (PEDOT) as the active layers have been reviewed. This review discusses the sensing mechanism and configurations of the sensors. The factors that affect the performances of the gas sensors are also addressed. The disadvantages of the sensors and a brief prospect in this research field are discussed at the end of the review.

No MeSH data available.