Page 240 - Polymer-based Nanocomposites for Energy and Environmental Applications

212 Polymer-based Nanocomposites for Energy and Environmental Applications

B (H2TPFP) doped with DBSA; sensor 2, conductive polymer (PPPX) doped with
porphyrin B (H2TPFP); sensor 3, conductive polymer (PPPX) doped with DBSA;
and sensor 4, conductive polymer (PPPX) doped with porphyrin B (H2TPFP) and
DBSA. The developed sensors were reproducible; response time was high for all
the analytes. All the sensors have good response with ethyl acetate among other
analytes [29]. This is a new method of preparation of sensor using a single conductive
polymer with varying porphyrin doping of different chemical structure.

7.5.3 PANI based nanocomposites
PANI is a promising conducting polymer which composite is a selective candidate for
sensor applications. Its effect toward sensor shall be multifolded when PANI is
reinforced with various nanomaterials. In literature, it was mentioned that sol-gel
technique can be adopted for in situ synthesis of very efficient rice-shaped PANI-
reinforced bismuth oxide nanocomposites [30]. The PANI solution was added to
bismuth oxide gel. Different solution mixtures were prepared by considering fixed
mixing volume ratios of 1:1 of organic polymer into which various volume ratio
inorganic reactants are mixed.
From TGA studies, it is noticed that the bismuth-decorated PANI nanocomposites
are more stable than corresponding PANI. The PANI/Bi 2 O 3 was deposited on a silver
2
electrode (AgE, surface area, 0.0216 cm ). The PANI/Bi 2 O 3 nanocomposite fabri-
cated on silver electrode is highly effective and acts as sensor toward toxicity and
is an efficient sensor with a fast response toward the health hazardous. The phenolic
compounds like 3-methoxyphenol that is in liquid phase can act as efficient sensor for
2
health sector and environmental issue. The calibration plot shows linear (r ¼0.9809)
over the 0.09 nM to 0.09 mM that is in 3-methoxyphenol concentration ranges. The
sensitivity is 0.8796 lAcm 2 lM-1, and the detection limit is 0.016 0.002 nM
(signal-to-noise ratio, at an SNR of 3). These are the ideal conditions for an ideal sen-
sor formed by a combination of organic-inorganic nanocomposites. Using effective
IdV method, we can prepare an ideal sensor that is used for sensing very hazardous
phenolic compounds. By sensing, we can prevent environmental side effects of
phenolic compounds on human health and his surroundings. The nanocomposites
have nontoxic, chemically stable, highly electric conducting, and high aspect ratio that
can be directly used for the target toxic analyte detection. Hence, the developed
rice-shaped PANI-reinforced bismuth oxide nanocomposites are reproducible, chemi-
cal, thermal, and electric stable and have better efficiency for sensor applications
in the field of environmental and health care. The schematic representation of
conducting polymers used in electrochemical sensor is shown in Fig. 7.5.
In another work, MWCNTs reinforced electrically conducting polymer composites
that were synthesized by solution casting method, and it was used for the detection of
ammonia gas. Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT/
PSS) and PANI were used as the conducting polymer, and the sensing response was
compared for ammonia gas at room temperature. PEDOT/PSS polymer composite-
based sensor was found to be more sensitive with less response time of about 16%
and 15 min, respectively; however, it had poor recovery for ammonia gas. Thermal