Page 238 - Polymer-based Nanocomposites for Energy and Environmental Applications

210 Polymer-based Nanocomposites for Energy and Environmental Applications

of aligned CNTs was carried out using silicon substrate with patterned Fe/Al 2 O 3
catalyst that is positioned on a horizontal quartz tube furnace at atmospheric pressure
at 750°C.

7.5 PNCs for sensor applications

Electrochemical sensors prepared from nanomaterials have a great impact on clinical
diagnosis in biomedical application, improved environmental monitoring, and secu-
rity surveillance in various sectors or for ensuring our food safety. Optimization of
immobilized enzymes can be done using nanoparticles because of its maximum sur-
face area per unit mass and high effective enzyme loading [21]. The sensors developed
from conducting polymeric materials in either the thin films or composite were effec-
tive sensors for organic compounds such as alcohols and molecules like NH 3 ,NO 2 ,
and CO that are volatile in nature (VOCs). Conducting polymers are used in electro-
nics and nanoelectric devices; biochemical sensors due to their unique properties such
as light weight have large surface area and high aspect ratio, flexible transport
properties, chemical specificities, easy availability, low price, easy processing, and
scalable productions [22]. The formation of nanocomposites is established in Fig. 7.3.
Conducting polymer nanowires are ultrasensitive, trace-level biological and
chemical nanosensors because of their tunable conductivity, flexibility, and chemical
diversity [24,25]. These materials are highly sensitive for biosensor applications due
to its large surface area and higher penetration depth for gas molecules as compared
with bulk materials and are reproducible. Conducting polymer composites were syn-
thesized from different methods such as polyaniline (PANI) and polypyrrol (PPy)
nanofibers that were from polymerization of their monomer units [26,27]. In earlier
report, a simple illustrative representation for the formation of nanocomposites is
presented in Fig. 7.3. Nanoparticles have improved tensile strength and optoelectronic
properties, and the organic polymers can be ease in processing, so a combined form of
organic polymer and nanoparticles is used for fabrication of a large number of devices.
Fig. 7.4 represents an example for the synthesis of nanocomposite from gold core/
polythiophene shell; this composite can be easily dispersed in many common organic
solvents. Due to which, it shows a great degree of applications in electric-electronic
devices [23].

Oxidant

Monomer Inorganic Nanocomposite
particles
Fig. 7.3 Formation of nanocomposites [23].