Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
Chapter 3
Synthesis of Polyaniline (PANI)
3.1 Introduction:
Polymer systems with unique properties are the recent fields of increasing
scientific and technical interest, offering the opportunity to synthesize a broad variety of
promising new materials, with a wide range of electrical, optical and magnetic property.
Technological uses depend crucially on the reproducible control of the molecular and
supramolecular architecture of the macromolecular via a simple methodology of organic
synthesis. Among the conducting polymer, Polyaniline (PANI) is one such polymer
whose synthesis does not require any special equipment or precautions. Conducting
polymers generally show highly reversible redox behavior with a noticeable chemical
memory and hence have been considered as prominent new materials for the fabrication
of the devices like industrial sensors. The properties of conducting polymers depend
strongly on the doping level, protonation level, ion size of dopant, and water content.
Conducting PANI is prepared either by electrochemical oxidative polymerization or by
the chemical oxidative polymerization method. The emeraldine base form of PANI is an
electrical insulator consisting of two amine nitrogen atoms followed by two imine
nitrogen atoms. PANI (emeraldine base) can be converted into a conducting form by two
different doping processes: protonic acid doping and oxidative doping. Protonic acid
doping of emeraldine base corresponds to the protonation of the imine nitrogen atoms in
which there is no electron exchange. In oxidative doping, emeraldine salt is obtained
from leucoemeraldine through electron exchanges. The mechanism causing the structural
changes is mainly recognized to the presence of -NH group in the polymer backbone,
whose protonation and deprotonation will bring about a change in the electrical
conductivity as well as in the color of the polymer. Considerable research effort is now
directed towards the development of sensors and artificial noses and electronic tongues
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
based on conducting materials used for the detection of chemical vapors and gases and
biological species [1].
3.2 Techniques of polymerization:
i. Bulk polymerization: The simplest method of polymerization where the reaction
mixture contains only the monomer and a monomer soluble initiator.
ii. Solution polymerization: This method is used to solve the problems associated
with the bulk polymerization because the solvent is employed to lower the viscosity
of the reaction, thus help in the heat transfer and reduce auto acceleration.
iii. Suspension polymerization: This method is used also to solve the problem of heat
transfer. It is similar to bulk polymerization where the reaction mixture is
suspended as droplets in an inert medium. Monomer, initiator and polymer must be
insoluble in the suspension media such as water.
iv. Emulsion polymerization: This is similar to suspension polymerization except that
the initiation is soluble in suspension media and insoluble in the monomer. The
reaction product is colloidally stable dispersion known as latex. The polymer
particles have diameter in the range of (0.05 - 1  m) smaller than suspension.
3.3 Conducting Polymer-Polyaniline(PANI):
PANI is the oxidative polymeric product of aniline under acidic conditions
and has been known since 1862 as aniline black [2]. Surville et. al. [3] in 1968 reported
proton exchange and redox properties with the influence of water on the conductivity of
PANI. In 1911 Mecoy and Moore [4] had suggested electrical conduction in organic
acids. However, interest in PANI was generated only after the fundamental discovery in
1977 that iodine doped polyacetylene has a metallic conductivity. PANI as a chemical
substance has been known for long time [5-6].
At the beginning of the 20th century organic chemists began investigating the
construction of aniline black and its intermediate products [7]. Wills Tatter and coworkers in 1907 and 1909 regarded aniline black as an eight-nucleus chain compound
having indamine structure [Fig. 3. 1].
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
3. 2
Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
H
H
H
H
N
N
N
N
N
N
N
N
H
H
H
H
H
Fig. 3.1: Indamine Structure
However, in 1910-12 Green and Woodhead [8] were able to report various constitutional
aspects of aniline polymerization. The conclusions of their study were as follows:
 There are four quinoid stages derived from the parent compound
leucoemeraldine.
 The minimum molecular weight of these primary oxidation of anilines
are in accordance with an eight-nucleus structure.
 The conversion of emeraldine into nigraniline consumes one atom of oxygen.
 The conversion of emeraldine into pernigraniline consumes two atoms of
oxygen.
 The conversion of nigraniline into pernigraniline consumes one atom of
oxygen.
 The reduction of emeraldine to leucoemeraldine consumes four atoms of
hydrogen.
 The reduction of nigraniline to leucoemeraldine consumes six atoms of
hydrogen.
 The reduction of pernigraniline to leucoemeraldine consumes eight atoms of
hydrogen.
These authors carried out oxidative polymerization studies using mineral acids
and oxidants such as persulphate, dichromate and chlorate and determined the oxidation
state of each constituent by redox titration using TiCl3. They also extended their studies
on the oxidative polymerization of o- and p- chloroaniline and o-anisidine and reported
that dimethylaniline remained unattacked under these experimental conditions.
This triggered research interest in new organic materials in the hope that
these would provide new and/ or improved electrical, magnetic, optic material or devices.
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
The hope was based on electronic structure and the combination of metal like or
semiconducting character with the processibility and flexibility of classical polymers and,
above all, the ease with which structural modification can be carried out via synthetic
organic chemistry methodologies. Among the conducting polymers, PANI has been the
most widely studied as a exclusive member for the conducting polymer family for the
following reasons.

Easy synthesis.

It is the only conducting polymer whose electronic structure and electrical
properties can reversibly be controlled by both oxidation and protonation.

It has interesting electrochemical behaviour.

It shows environment stability.

Ease of non-redox doping by protonic acids.
3.4 Structure of Polyaniline:
The protonation and deprotonation and various other physico-chemical
properties of PANI can be said to be due to the presence of the -NH- group. The general
structure of PANI can be shown above in Fig. 3.2.
Figure 3.2-General structure of PANI [1]
Green and Woodhead [5] were the first to depict PANI as a chain of aniline
molecules coupled head-to-tail at the para position of the aromatic ring. They have proposed a linear octameric structure for PANI. Polyaniline, a typical phenylene based polymer, has a chemically flexible –NH– group in the polymer chain flanked by phenyl rings
on either sides. The diversity in physicochemical properties of PANI is traced to the –
NH– group. Out of several possible oxidation states, the 50 % oxidized emeraldine salt
state shows electrical conductivity [8-9].
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
In combination with comparable results obtained with other similar polymers such
as PPy and PTh, PANI have caused a rapid increase in experimental investigations into
the mechanism and kinetic of the formation, molecular structure, electro-optical and
believable application [10].
Table 3.1. : Raman assignments of PANI [11]
Frequencies (cm-1)
Assignments
1160–1180
C–H bending
1230–1255
C–N stretching
1317–1338
C–N+ stretching
1470–1490
C=N stretching
1515–1520
N–H bending
1580
C=C stretching
1600–1620
C–C stretching
3.5 Conductivity of PANI:
As mentioned below, PANI exists in three oxidation states (leucoemeraldine,
emeraldine and pernigraniline forms) that differ in chemical and physical properties [12].
Only the green protonated emeraldine has conductivity on a semiconductor level of the
order of 100 S cm-1, many orders of magnitude higher than that of common polymers
(<10-9 S cm-1) but lower than that of typical metals (>104 S cm-1). Protonated PANI
converts to a non-conducting emeraldine base when treated with alkali solutions (Fig.
3.3) [13].
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
Figure 3.3: Emeraldine salt is protonated in the alkaline medium to emeraldine
base. A- is arbitrary ion, e.g., chloride
The conductivity of PANI can be changed by doping, and spans a very wide range (<10-12
to 105 S cm-1) depending on the level of doping [14]. The changes in physicochemical
properties of PANI occurring in response to various external stimuli are used in various
applications, e.g., in sensors and actuators [15]. Other uses are based on the combination
of electrical properties typical of semiconductors with materials properties characteristic
of polymers, like the development of “plastic” microelectronics, electrochromic devices.
The establishment of the physical properties of PANI reflecting the conditions of
preparation is thus of fundamental importance [16]. Polyaniline (PANI) and poly
(ethylene dioxythiophene) (PEDT) have a much higher conductivity and stability,
combined with a low absorption as compare to alkoxy-substituted polythiophenes. It is
postulated that, this is due to the fact that the doping process in these materials is
different, involving no shifts in absorption peaks and leading to low-lying near IR
absorption bands at less than 0.6eV. [17]. During the course of polymerization reaction,
these cations of intermediate stability dimerize, and further radical coupling reaction
leads to the formation of green PANI [18].
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
3.6 Interconversion of different oxidation states of PANI (redox procedure):
The oxidation of monomeric aniline, either electrochemically or in acidic
solution, leads to stable polymers in at least three distinct oxidation states. In 1985, Alan
MacDiarmid and co-workers published a remarkable paper in this context [19].
Figure 3.4: Various possible oxidation states of PANI [20]
The difference in the composition of amine and imine segments of PANI generates
several
oxidation
states of this
material
ranging
from
completely reduced
leucoemeraldine to completely oxidized pernigraniline states as shown in Fig. 3.4. The
different forms of PANI can be readily converted to one another by simple redox
methods (Fig. 3.5).
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
Figure 3.5: Interconversion of different oxidation states of PANI (redox procedure)
[20]
Table 3.2 The different forms of PANI [21]
Type of form
Name
Colour
Conductivity
S cm−1
Reduced form
Oxidized form
Polyleucoemeraldine base Transparent
<10−5
Polyprotoemeraldine base
Transparent
<10−5
Polyemeraldine base
Blue
<10−5
Polynigraniline base
Blue
<10−5
Polypernigraniline base
Purple
<10−5
Polyemeraldine salt
Green
~15
The conductive form of PANI is the protonated polyemeraldine or polyemeraldine salt
whose color is green and the conductivity is around 15 S cm−1 [22], whereas the
conductivity of polyemeraldine base is around 10−5 S cm−1. Note that the conductivity of
a metal is around 103 S cm−1.
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
3.7 Synthesis of PANI:
There are several reports of PANI found in the literature over the decades about
the structure and constitutional aspect of aniline polymerization. The most universal
synthesis of PANI involves oxidative polymerization, in which the polymerization and
doping occurs at the same time, and may be accomplished either electrochemically or
chemically. Electrochemical methods tend to have lower yields than chemical yields [22].
3.7.1 Chemical Synthesis (Oxidative polymerization):
Synthesis of PANI by chemical oxidation way involves the use of either
hydrochloric or sulfuric acid in the presence of ammonium persulfate as the oxidizing
agent in the aqueous medium. The principal function of the oxidant is to withdraw a
proton from an aniline molecule, without forming a strong co-ordination bond either with
the substrate / intermediate or with the final product (Fig. 3.6). However smaller quantity
of oxidant is used to avoid oxidative degradation of the polymer formed. Polymer chains
proceeds by a redox process between the growing chain and aniline with addition of
monomer to the chain end. The high concentration of a strong oxidant, (NH4)2S2O8, at the
initial stage of the polymerization enables the fast oxidation of oligomers and polyaniline,
as well as their existence in the oxidized form.
H
N
.. H
H
-e-
H
.N
+
+
N H
.
H
Aniline
H
.
N
.. H +
+
N H
+
2H
H
Aniline
H
H
N
..
N
..
Polyaniline
Figure 3.6: Homopolymerization of PANI [23].
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
PANI is mostly synthesized by aniline oxidation either with a chemical oxidant (chemical
route) or through electrochemistry. Other original synthesis is proposed like plasma
Polymerization
[24],
autocatalytic
polymerization
[25]
or
inverse
emulsion
polymerization [26].
Chemical synthesis requires three reactants: aniline, an acidic medium (aqueous
or organic) and an oxidant. The more common acids are essentially hydrochloric acid
(HCl) and sulfuric acid (H2SO4). Ammonium persulfate ((NH4)2S2O8), potassium
dichromate (K2Cr2O7), cerium sulfate (Ce(SO4)2), sodium vanadate (NaVO3), potassium
ferricyanide (K3(Fe(CN)6)), potassium iodate (KIO3), hydrogen peroxide (H2O2) are
recommended as oxidants [27]. However, the more popular synthesis is run with a 1 mol
aqueous hydrochloric acid solution (pH between 0 and 2), ammonium persulfate as
oxidant with an oxidant/aniline molar ratio ≤1.15 in order to obtain high conductivity and
yield [28]. The solution temperature is comprised between 0 and 2 ◦C in order to limit
secondary reactions [29]. The duration of the reaction varies generally between 1 and 2
hr. The experimental part consists of adding slowly (even drop by drop) the aqueous
ammonium persulfate solution to the aniline/HCl solution, both solutions being precooled to nearly 0 ◦C. The mixture is stirred for about 1 hr. The obtained precipitate is
removed by filtration and washed repeatedly with HCl and dried under vacuum for 48 hr
[28].The obtained material is polyemeraldine salt: polyemeraldine hydrochloride (PANIHCl), green colored. To obtain polyemeraldine base, polyemeraldine hydrochloride is
treated in an aqueous ammonium hydroxide solution for about 15 hr. The obtained
powder is washed and dried.
3.7.2 Electrochemical synthesis:
The electrochemical synthesis of conducting polymer is an electro-organic
process rather than an organic electrochemical one, because the more emphasis is on the
electrochemistry and electrochemical process rather than on organic synthesis.
Electrochemistry has contributed significantly to the developments in conducting
polymers. In most of the applications, it is essential to synthesize polymers into a thin
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
film of well defined structure, preferably with a large area. For preparation of such films,
electrochemical synthesis is a standard method [30-34]. The conducting polymers which
are not easily processed, when prepared by chemical routes, are synthesized in the form
of films adhering to the electrode, so that a study of the optical and electrical properties
can be carried out in-situ by using electroanalytical techniques. The electrochemical
synthesis of conducting polymers is similar to the electrodeposition of metals from an
electrolyte bath; the polymer is deposited on the electrode surface and also in the in-situ
doped form.
Three electrochemical methods can be used to PANI synthesisa) Galvanostatic method when applied a constant current,
b) Potentiostatic method with a constant potential,
c) Potentiodynamic method where current and potential varies with time.
Whatever the method is, a three-electrode assembly composes the reactor vessel:
a working electrode on which the polymer is deposited, a counter electrode also named
auxiliary electrode (platinum grid) and a reference electrode (in most cases, a saturated
calomel electrode (SCE)).
The more common working electrode is a platinum one, but PANI depositions have also
been realized onto conducting glass (glass covered by indium-doped tin oxide (ITO)
electrode), Fe, Cu, Au, graphite, stainless steel, etc [28]. PANI can be then peeled off
from the electrode surface by immersion in an acidic solution.
As compared to chemical synthesis, this route presents several advantages [35] as
cleanness because no extraction from the monomer–solvent–oxidant mixture is
necessary, doping and thickness control via electrode potential, simultaneous synthesis
and deposition of PANI thin layer.
The electrochemical synthesis route offers many advantages over the chemical
method listed below.

It is simple and less expensive technique. Therefore, electrodeposition of
conducting polymer on oxidizable conducting glass is extremely
economical.
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications

Unlike chemical method, there is no need of catalyst and therefore, the
electrodeposited polymers and co-polymers are essentially pure and
homogeneous.

Doping of the polymer with desired ion can be considered simultaneously
by changing the nature of ions in the solution.

The conducting polymers can be obtained directly in thin film forms as
coating on electrodes and the properties of these coatings can be controlled
effectively by proper choice of the electrochemical process variables.

Reduction in the possible pollution by adopting the suitable system for
electropolymerization using modern sophisticated instrument.
The electrochemical synthesis is normally carried out in a single compartment
cell. The cell consists of the electrodes, electrolyte and power supply.
3.8 Polymerization mechanism of PANI:
Figure 3.7: Formation of the aniline radical cation
The various methods of polyaniline synthesis stimulate a multitude of
polymerization mechanisms of aniline. The electrochemical polymerization mechanism
seems to be the most investigated compared to the chemical one [28]. However, a close
similarity can be considered for chemical and electrochemical processes. The synthesis
mechanism corresponds to a polycondensation because it proceeds by steps. The first
most feasible oxidation step corresponds to the radical cation formation by an electron
transfer from the 2 s energy level of the aniline nitrogen atom as shown in Fig. 3.7,
whatever the pH value is. As a kinetic point of view, it is the limiting step and a catalyst
may accelerate it. Then, the reaction is autocatalyzed. This aniline radical cation has three
resonance forms, given in Fig.3.8. Among these three resonance forms, the form (2) is
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
the more reactive one because, on the one hand, of its important substituent inductive
effect, and on the other hand, of its absence of steric hindrance.
Figure 3.8-Resonance forms of the aniline radical cation
The next step in Fig.3.8, at the least in acidic medium, would be the reaction between
the radical cation and the resonance form (2), the so-called “head to tail” reaction,
favored in acidic medium (aqueous or organic) and corresponds to the dimer formation
[36-37].
Figure 3.9-Dimer formation
Figure 3.10 -Formation of the radical cation dimer
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
Next step, the dimer is oxidized to form a new radical cation, as shown in Fig. 3.9.The
formed radical cation can react either with the radical cation monomer or with the radical
cation dimer to form, respectively, a trimer or a tetramer, according to the mechanism
proposed previously, and this up to the polymer Fig. 3.11.
Figure 3.11- A way of polymer synthesis
For a long time, the PANI was supposed to be an octamer. However, the formation of a
longer chain is now proved with an average molar mass evaluated to be more than 104 g
mol−1 [38].
3.9 PANI doping:
The PANI must be doped if associated to electronic conducting polymers. The
term “doping” is employed here by analogy with semiconductors like silicon or
germanium in which atoms like phosphorous or boron are introduced. Conducting
polymer doping consists to insert into the polymer, electron acceptor molecules
(oxidation) or electron donor molecules (reduction). The obtained polymer is then
considered as a p-type or n-type one, respectively.
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
PANI is a specific conducting polymer because of its conducting
mechanism induced either by the oxidation of the polyleucoemeraldine base or by the
protonation of the polyemeraldine base. The two routes are shown in Fig.3.12.
Figure 3.12:-Doping mechanisms of PANI
3.9.1 Oxidative doping:
Figure 3.13 (a) Oxidative doping with Cl2
The oxidative doping is realized through chemical or electrochemical processes
from the totally reduced form of PANI: polyleucoemeraldine base as shown in Fig. 3.13
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
3. 15
Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
indicates a way of polymer synthesis. Polyleucoemeraldine base is prepared by reduction
of polyemeraldine salt with phenylhydrazine or hydrazine solutions by dipping for 5 or 6
min [39].The chemical oxidative doping is run either with a chlorine or a less toxic iodine
agents in a carbon tetrachloride solution, or with (NO)+ (PF6)−, FeCl3 or SnCl4 organic
solutions, or with oxygen or hydrogen peroxide in an aqueous acidic solution. The
following examples illustrate the oxidative doping with Cl2: Fig.3.13 (a) and also with
H2O2 in an acidic solution HA (Fig. 3.13(b)):
Figure 3.13 (b) Doping with H2O2 in an acidic solution HA:
In the latter case, the nature of the counter-ion A− (Cl−, HSO4 −, H2PO4 −) is controlled.
When Cl2 is considered both as the oxidant and the dopant, H2O2 only oxidizes PANI
doped with the acidic solution. Although chemical doping is a straightforward and wellorganized process, but the control of the doping level δ is difficult. Electrochemical
doping solves this problem since the doping level is determined by the voltage applied
between the conducting polymer and the counter Electrode [40]. The electrochemical
doping of polyleucoemeraldine base can be written as Fig. 3.14:
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
3. 16
Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
Figure 3.14: Electrochemical doping of polyleucoemeraldine
The counter-ions A− of the electrolytic solution are inserted in the polymer backbone.
3.9.2 Acidic doping:
The acidic doping is a exceptional doping case, where no change of the number of
electrons associated with the polymer backbone occurs. The acidic doping consists to
treat the emeraldine base with a strong acid (HCl, H2SO4) that induces the protonation of
the imine sites to give the polyemeraldine salt, through a mechanism illustrated in
Fig.3.15.
Figure 3.15: Mechanism of acidic doping
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
3. 17
Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
Considering the resonant structures, charge and spin can be largely delocalized that
explains the observed conductivity (as shown in above Table 3.2). However, drawbacks
of hydrochloride polyemeraldine salt are its poor solubility in most common solvents,
and its conductivity alteration with moisture and temperature. Then to improve the
solubility of conducting polymers and their temperature stability (nearly up to 200 ◦C),
few approaches have been developed. One of them implies the use of dopants other than
HCl in the monomer solution. So, polyacrylic acid [41] or other polymeric acids, acrylic
acid (AA) [42], etc. have been added as dopants in the monomer solution.
3.10 Synthesis of nanoparticles of polyaniline (PANI) using emulsion
polymerization method:
Synthesis of nano PANI particle by waterborne latex is much better than the
synthesis based on organic solvent or strong acid because the universal solvent water in
the waterborne PANI latex does not pollute the environment. The waterborne latexes,
thus, were found to be highly suitable and they avoid the use of organic solvents or strong
acids under environmentally benign conditions. It is well known that the PANI has very
partial solubility in common organic solvents and water, preventing its use in the coating
industries [43]. To solve this difficult processing problem, several modifications, such as
inserting substituent either on phenyl ring or on the nitrogen [44-45], surface
modification with inorganic pigment [46], blend and composite [47-48], and dispersion
of nano particles in various binders [49], have been suggested. The design and production
of PANI-based coating systems with commercial viability require a minimum possible
agglomeration of ICP, well-dispersed nanoparticles (70–100 nm) of uniform size and
having superior adhesion [50]. Development of conducting polymeric nanoparticles
based corrosion inhibitors with self-cleaning properties, discoloration resistance, high
scratch as well as wear resistance and environmentally benign synthesis of conducting
polymer are expected to cause a major revolution in the world of corrosion prevention
[51].
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
3.10.1 Advantages of emulsion polymerization:
i) Easy heat removal and control.
ii) The polymer is obtained in a convenient, easily handled and often directly useful form.
iii) High molecular weight can be obtained.
iv) The very small particles formed resist agglomeration thus allowing the preparation of
tacky polymers.
v) Inverse phase (water in oil) emulsions are possible.
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
References:
1. Debarnot, D. N. and F. P. Epaillard, Anal. Chim. Acta 475, 1–15(2003).
2. R. Ratheesh and K. Viswanathan, IOSR Journal of Applied Physics (IOSR-JAP)
2278-4861. Volume 6, Issue 1 Ver. II PP 01-09, (Feb. 2014).
3. Advanced Functional Molecules and Polymers, Volume 3, Hari Singh Nalwa,
(2001).
4. Franklin L. Hunt, J. Am. Chem. Soc., 33 (6), 795–803 (1911).
5. A.G. Green and A.E. Woodhead, J. Chem. Soc.97, 2388–2403, (1910).
6.
A.G. Green and A.E. Woodhead, Aniline-black and allied compounds Part II, J.
Chem. Soc. 101, pp. 1117–1123 (1912).
7. Green A. G., Woodhead A. E., J. Chem. Soc., Trans., 101, 1117, (1912)
8. P. S. Rao, D. N. Sathyanarayana and T. Jeevananda, In Advanced Functional
Molecules and Polymers.
9.
H. S. Nalwa (ed.), Gordon and Breach, Tokyo, Vol.3, p. 79,(2001).
10. T.A. Skotheim and J.R. Reynolds (eds), Handbook of Conducting Polymer, Vol.
I, Theory, Synthesis, Properties and Characterization, Vol. II, Processing and
Application, 3rd edn, CRC Press, Boca Raton, (2007).
11. Duong Ngoc Huyen*, Tran Van Ky and Le Hai Thanh, Journal of Experimental
Nanoscience, Vol. 4, No. 3, 203–212, (September 2009).
12. E. M. Genies, A. Boyle, M. Lapkowski, C. Tsintavis, Synth. Met. 36 139, (1990).
13. J. Stejskal, R. G. Gilbert, Pure Appl. Chem. 74, 857 (2002).
14. P. S. Rao, D. N. Sathyanarayana, In Advanced Functional Molecules and
Polymers, H. S. Nalwa (ed.), Gordon & Breach, Tokyo, (2001).
15. J. Stejskal, R. G. Gilbert, Pure Appl. Chem. 74, 857, (2002).
16. Hung
Van
Hoang,
Electrochemical
Synthesis
of
Novel
Polyaniline-
Montmorillonite Nanocomposites and Corrosion Protection of Steel, Chemnitz
University of Technology,(2006).
17. Havinga E.E., Mutsaers C.M.J., Jenneskens L.W., Chem. Mater., 8, 769, (1996).
Cloutier R., Leclerc M., J. Chem. Soc., Chem. Commun., 1194, (1991).
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
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Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
18. Ayşegül Gök, Bekir Sari & Muzaffer Talu, International Journal of Polymer Anal.
Charact., 11: 227–238, (2006).
19. MacDiarmid, A. G., Chang, J., Halpern, M., Huang, W., Mu, S., Somasiri, N.,
Wu, W. and Yangier, S. Molec. Cryst. Liq. Cryst., 121, 173,(1985).
20. A Ph.D. thesis of Subrahmanya Shreepathi, entitled Dodecylbenzenesulfonic
Acid: A Surfactant and Dopant for the Synthesis of Processable Polyaniline and
its Copolymers, Technischen Universität Chemnitz, Germany (2006).
21. D. Nicolas-Debarnot, F. Poncin-Epaillard, Analytica Chemica Acta, 475, 1-15
(2003).
22. J. Stejskal, I. Sapurina, J. Prokes, J. Zemek, Synth. Met. 105, 195–202, (1999).
23. New Polymers for Special Applications", book edited by Ailton De Souza Gomes,
ISBN 978-953-51-0744-6, (2012).
24. G.J. Cruz, J. Morales, M.M. Castillo-Ortega, R. Olayo, Synth. Met. 88 213–218,
(1997).
25. C. Liao, M. Gu, Thin Solid Films 408, 37–42,(2002).
26. P. Swapna Rao, S. Subrahmanya, D.N. Sathyanarayana, Synth. Met. 128 311–
316, (2002).
27. A. Malinauskas, Polymer 42, 3957–3972, (2001).
28. A.A. Syed, M.K. Dinesan, Talanta 38 (8) 815–837, (1991).
29. S. Picart, F. Miomandre, V. Launay, Bull. de l’Union des Physiciens 95, 581–592,
(2001).
30. Borole D. D., Kapadi U. R., Mahulikar P. P., Hundiwale D. G., Ph. D. Report,
North Maharashtra University, Jalgaon, (2003).
31. Skotheim T. A., Handbook of Conducting Polymers, Vol. I and II, Marcel
Dekker, New York, (1986).
32. Alcaser L., Conducting Polymers: Special Applications, Dorhrecht, Holland,
(1987).
33. Aldissi M., Intrinsically Coducting Polymers: An emerging Technology, Kluwar
Academic Publishers, Dorhrecht, Holland, (1993).
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
3. 21
Synthesis and Characterization of Thin Films of Conducting Polymers for Gas Sensing Applications
34. Nalwa H. S., Handbook of Organic conductive Molecules and Polymers, Vol. I IV, John Wiley and Sons Ltd., (1997).
35. S. Picart, F. Miomandre, V. Launay, Bull. de l’Union des Physiciens 95, 581–592,
(2001).
36. E.P. Koval’chuk, S. Wittingham, O.M. Skolozdra, P.Y. Zavalij, I.Y. Zavaliy.
37. O. V. Reshetnyak, M. Seledets, Mater. Chem. Phys. 69, 154–162, (2001).
38. S.C. Yang, SPIE Inst. Ser. 4, 335–365, (1988).
39. M. Kumar Ram, G. Mascetti, S. Paddeu, E. Maccioni, C. Nicolini, Synth. Met. 89,
63–69, (1997).
40. A.J. Heeger, Synth. Met. 125, 23–42, (2002).
41. H. Hu, J.M. Saniger, J.G. Banuelos, Thin Solid Films 347, 241–247, (1999).
42. A.A. Athawale, M.V. Kulkarni, V.V. Chabukswar, Mater. Chem. Phys. 73 (1),
106–110, (2002).
43. Yao Bin, Wang Gengchao, Ye Jiankun, Li Xingwei, Mat. Lett. 62, 1775 -1778,
(2008).
44. Chen S. A., Huang G. W., Am J., Chem. Soc. 116, 7939 - 7940, (1994).
45. Nguyen M. T., Diaz A. F., Macromol., 28, 3411 - 3415, (1995).
46. Andrea Kalendova, David Vesely, Jaroslav Stejskal, Miroslava Trchova, Prog.
Org. Coat., 63, 209 - 221, (2008).
47. Oh S. G., Im S. S., Curr. Appl. Phys., 2, 273 - 277, (2002).
48. Byoung Ho Jeon, Seok Kim, Min Ho Choi, In Jae Chung, Synt. Met., 104, 95 100, (1999).
49. Radhakrishnan S., Siju C.R., Debajyoti Mahanta, Satish Patil, Giridhar Madras,
Electro. Acta, 54, 1249 - 1254, (2009).
50. Heilman, A, Polymer Films with Embedded Metal Nanoparticles, Springer, New
York (2003).
51. Xin-Gui Lia, Mei-Rong Huanga, Jian-Feng Zenga, Mei-Fang Zhub, Collo.Surf.
A: Physicochem. Eng.,Aspects, 248, 111 - 120, (2004).
Mr.Ravindrakumar G. Bavane, SOPS, NMU, Jalgaon (2014)
3. 22