Page 513 - Polymer-based Nanocomposites for Energy and Environmental Applications

466 Polymer-based Nanocomposites for Energy and Environmental Applications

yield enhanced sorption capacity [3]. Apart from this, for safe disposal of spent adsor-
bents, polymers are suitable for this purpose [4]. Today, polymeric materials appear to
assume leading position in most of the environmental and wastewater treatment
applications.
This chapter focuses on the recent development in the use of polypyrrole and its
nanocomposites for radioactive content removal from liquid radioactive wastes.
Throughout this perspective, we examine the general synthesis approach of polypyrrole
and then discuss the shortcomings of traditional polypyrrole in environmental remedi-
ation of radioactive materials. Particular attentions were given to the polypyrrole-based
nanocomposites as efficient adsorbents in environmental remediation of radioactive
materials, which also includes authors’ previous efforts along with other literature. Gen-
eral outlook of the future prospects of polypyrrole-based nanocomposites in uptake of
radioactive materials and possible problems they may encounter is presented.

17.2 Conducting polymer-polypyrrole

Among the most fascinating discoveries in the field of polymer science is conducting
polymers (CPs). For a long time, conventional polymers are known to have good
dielectric properties and are therefore regarded as electrically insulating materials,
which made them to be used as electric insulating components and replacement for
woods, ceramics, shoes, and clothes [5,6]. However, this perception was later changed
as efforts toward understanding the intrinsic nature of polymers showed that some
polymers exhibit signs of conductivity. Historically, it began with the synthesis of ani-
line black (so-called name for any product produced by oxidation of aniline) around
1885, followed by the synthesis of polypyrrole in the 1960s, but little was still known
on polymer properties in those periods, particularly their electroactive property. In
1977, Shirakawa and colleagues, working together at the University of Pennsylvania,
synthesized polyacetylene (PA) and discovered its inherent conductivity, which was
reported to increase upon doping with iodine for the first time [7,8]. Subsequent to the
discovery of intrinsic property of PA polymer with its unexpected conductivity com-
pared with the conventional metals, intense research efforts have resulted into the
development of other families of CPs such as polypyrrole (PPy), polyaniline
(PANI), polythiophene (PTh), and polyfluorene (PF), for myriad of product applica-
tions. Following this significant development, Shirakawa, MacDiarmid, and Heeger
were recognized with a Nobel Prize in Chemistry in 2000, for pioneering the discovery
of CPs. Today, CPs have become a new interdisciplinary field of research and
exhibited a broad application prospects in biological sensors, sensitive membranes,
artificial muscles, actuators, corrosion prevention, laser materials, electronic
shielding, visual displays, solar materials, high-energy batteries, and environmental
remediation [9].
As one of the novel CPs, PPy has been widely studied due to its superior electric
conductivity, promising environmental stability, excellent thermal stability, and redox
nature [10]. The easiness of the preparation procedures and low cost of the initial
monomers are also part of the interesting features of PPy [11]. Doping and conjugated