Page 241 - Polymer-based Nanocomposites for Energy and Environmental Applications

Polymer nanocomposites for sensor devices 213

Possesses

Higher
Large
electrical
surface conductivity
area
Polymer Nanocomposite (PNC) Modified Electrode Fast electron

transfer rate

Demonstrates performance parameters (below) for most of
the electroactive analytes

Higher sensitivity Lower detection- Good reproducibility
and selectivity limits and stability
Fig. 7.5 Schematic representation of conductive polymer used for electrochemical sensor.
Reproduced from Shrivastava S, Jadon N, Jain R. Next generation polymer nanocomposites
based electrochemical sensors and biosensors: a review. Trends Anal Chem 2016;82:55–7,
with permission from Elsevier Science.

stability of the MWCNT-PEDOT/PSS composite was significantly better than that of
MWCNT-PANI composite. The MWCNT-PEDOT/PSS composite-based sensor with
less recovery time was obtained using the combination of heat and DC electric field in
the experiment [31]. The resistance of the sensor increases linearly with each cycle of
exposure of ammonia gas to the sensor chamber until the saturation state is reached.
Lower detection limit for ammonia gas was 1 ppm that indicates that MWCNT-
PEDOT/PSS composite sensor has promising application for ammonia gas sensor
with excellent sensitivity, good thermal stability, appreciable response-recovery time,
and excellent repeatability.

7.5.4 Polypyrole based nanocomposites
Among different conducting polymer composites, PPy is a prominent matrix used in
sensor device. The polymerization of PPy, α-Fe 2 O 3 , and their nanocomposites were
prepared by sol-gel technique and by using synthetic solid-state approach. By using
spin coating technique, nanocomposite films of PPy/α-Fe 2 O 3 and PPy/α-Fe 2 O 3 were
fabricated on glass substrates. The formation of these hybrid nanocomposites were
verified and confirmed by FTIR and XPS. From morphological investigation, FESEM
images confirm that the nanocomposite films consist of porous granular structures.