ORIGINAL PAPER

Electrolyte type and concentration effectson poly(3-(2- aminoethyl thiophene) electro-coatedon glassy carbon electrode via impedimetric study

Murat Ates • Tolga Karazehir • Fatih Arican •

Nuri Eren

Received: 31 July 2012 / Accepted: 19 December 2012 / Published online: 9 January 2013

� Iran Polymer and Petrochemical Institute 2012

Abstract In this study, 3-(2-Aminoethyl thiophene)

(2AET) monomer was electropolymerized on glassy car-

bon electrode (GCE) using various electrolytes (lithium

perchlorate (LiClO4), sodium perchlorate (NaClO4), tetra-

butyl ammonium tetra fluoroborate (TBABF4) and tetra-

ethyl ammonium tetra fluoroborate (TEABF4) in

acetonitrile (CH3CN) as solvent. Poly(3-(2-aminoethyl

thiophene) (P(2AET))/GCE was characterized by cyclic

voltammetry (CV), Fourier transform infrared reflectance

spectrophotometry (FTIR-ATR), scanning electron

microscopy, energy dispersive X-ray analysis (EDX), and

electrochemical impedance spectroscopy (EIS) techniques.

The electrochemical impedance spectroscopic results were

given by Nyquist, Bode-magnitude, Bode-phase, capaci-

tance and admittance plots. The highest low frequency

capacitance (CLF) value obtained was 0.65 mF cm-2 in

0.1 M LiClO4/CH3CN for the initial monomer concentra-

tion of 1.5 mM. The highest double layer capacitance

(Cdl = ~0.63 mF cm-2) was obtained in 0.1 M LiClO4/

ACN for [2AET]0 = 0.5, 1.0 and 1.5 mM. The maximum

phase angles (h = 76.1o at 26.57 Hz) and conductivity

(Y00 = 3.5 mS) were obtained in TEABF4/ACN for

[2AET]0 = 0.5 and 1.0 mM, respectively. An equivalent

circuit model of R(Q(R(Q(R(CR))))) was simulated for

different electrolytes (LiClO4, NaClO4, TBABF4 and

TEABF4)/P(2AET)/GCE system. A good fitting was

obtained for the calculated experimental and theoretical

EIS measurement results. The electroactivity of P(2AET)/

GCE opens the possibility of using modified coated elec-

trodes for electrochemical micro-capacitor electrodes and

biosensor applications.

Keywords 3-(2-Aminoethyl thiophene) � Electrolyte �Scanning electron microscopy � Concentration �Circuit model

Introduction

Conjugated electroactive polymers have increasingly

become of significant interest worldwide due to their

inherently physical, mechanical and electronic properties

[1]. The modification by functionalization of the electro-

active monomer before polymerization [2–4], based on the

electronic properties of the neutral semiconducting form of

conjugated systems has had a great effect on the polymer

chemistry [5, 6]. The aspects of physical, mechanical and

electronic properties have been studied in charge storage

devices which were lightweight, formable, and redox stable

[7].

Conducting polymers were prepared either by chemical

or electrochemical polymerization. The electrochemical

synthesis offers several advantages, including rapidity,

simplicity, generation of the polymer in the doped state and

easy control of thickness of the film generated [8, 9].

Functional conjugated polymers show good electro-activity

due to their electro generation on the electrode surface

[10–14]. Due to their good processability and, outstanding

chemical and electrochemical stability, conducting poly-

mers have attracted more attentions and are expected to be

M. Ates (&) � T. Karazehir � F. Arican � N. Eren

Department of Chemistry, Faculty of Arts and Sciences,

Namik Kemal University, Degirmenalti Campus,

59030 Tekirdag, Turkey

e-mail: mates@nku.edu.tr

URL: http://mates-en.nku.edu.tr/

T. Karazehir

Department of Chemistry, Faculty of Arts and Sciences,

Istanbul Technical University, Maslak, Istanbul, Turkey

Iran Polymer and

Petrochemical Institute 123

Iran Polym J (2013) 22:199–208

DOI 10.1007/s13726-012-0117-z

used in many fields, such as sensors [15–18], supercapac-

itors [19–22] and solar cells [23, 24].

Among conducting polymers, poly(thiophenes) can be

used in many fields, such as solar cells [25], supercapacitors

[26], and field-effect transistors [27] due to its environ-

mental [28], thermal stability [29], and ease of structure

modification [30, 31]. Physicochemical properties of thio-

phene derivatives can be easily modified by substitution

of the macromolecular chain by different functional

groups [32, 33]. Polymerization of thiophene substituted in

b-position by an alkyl chain is not very difficult. However,

when the thiophene carries bulky substituents, the poly-

merization becomes frequently less easy or even impossible

[34, 35]. Thiophene-based functional conducting polymers

have problems of solubility and easy processability [36, 37].

This problem was overcome by the incorporation of sub-

stituents to the 3-position of the thiophene ring, which

produced not only processable conducting polymers, but

also allowed the complete chemical and physical charac-

terization of the prepared materials [38]. Introduction of

long alkyl side chains increases the solubility in organic

solvents, while hydrophilic substituents produce polythio-

phene soluble in water and/or polar solvents [39].

Electrochemical impedance spectroscopy (EIS) has been

considered as a technique that is suitable to study the

interfacial process [40] to supply important information,

such as double layer capacitance, charge transfer resis-

tance, diffusion impedance, and solution resistance

[41, 42]. EIS gives information on possible mechanisms in

electrochemical kinetics, but is unable to identify the nat-

ure of species formed or adsorbed at the electrode surface

during the reaction [43]. EIS results are analyzed by an

electrical equivalent circuit, which is a mathematical–the-

oretical model to interpret the experimental data [44, 45].

However, electrical or physical properties are not directly

obtained from an EIS experiment, and modeling impedance

data using an equivalent circuit is to assume that the

material behaves as a flat or even rough surface [46]. The

most used models for the interpretation of EIS data

for conducting polymers are based on insertion models

[47–49]. EIS is an outstanding electroanalytical measure-

ment technique when compared with other techniques,

such as cyclic voltammetry (CV), amperometry and po-

tentiometry since the potentials applied to the surfaces are

very small (typically 10–20 mV amplitude sinusoids) [50].

In this paper, electrolyte type and concentration effects

on poly(3-(2-aminoethyl thiophene)/GCE is given by

electrochemical impedance spectroscopy technique. In lit-

erature, there is limited amount of paper to investigate

three types of poly(thiophene)s having amino substituents

of poly(3-aminoethyl thiophene), poly(3-aminododecyl

thiophene) and poly[2,5-(3-octadecyl thiophene)-alt-2,5-

(3-aminoethyl thiophene)] [51]. Spin coated films of

hydrogen bromide salt of poly(aminoalkyl) substituents

were soaked in aqueous solution of PbBr2 by Noto et al.

[52]. As far as authors are aware, in literature, there is no

previous study on the electropolymerization of 3-(2-ami-

noethyl thiophene) on glassy carbon electrode in different

types and concentrations of electrolytes by EIS method.

Experımental

Materials

The monomer of 3-(2-aminoethylthiophene) (2AET) was

provided by Sigma-Aldrich, USA. All other reagents

included Acetonitrile (Aldrich, 99.93 %), and the sup-

porting electrolytes: lithium perchlorate (LiClO4, Fluka

Chemie GmbH, Bushs, Switzerland), sodium perchlorate

(Aldrich,[98.0 %), tetraethyl ammonium tetrafluoroborate

(Alfa Aesar, purity [98 %), tetrabutyl ammonium tetra-

fluoroborate (Alfa Aesar, purity[98 %) were used without

any treatment or further purification. Carbon fiber micro

electrodes (CFMEs, Sigri Carbon, Meitengen, Germany)

were prepared using a 3-cm long bundle of the electrodes

(average diameter *7 lm) attached to a copper wire with

a Teflon tape. Numbers of CFMEs in the bundle were about

10 which were counted under a digital microscope. One

centimeter of the CFME was dipped into the solution to

keep the electrode area (*0.022 cm2).

Instrumentation

Cyclic voltammetry (CV) was performed using PARSTAT

2273 (Princeton Applied Research, USA, software: pow-

ersuit and Faraday cage: BASI Cell Stand C3) in a three

electrode configuration, which employing glassy carbon

electrode (GCE) (area: 0.07 cm2) as the working electrode,

platinum wire as the counter electrode and Ag/AgCl as the

reference electrode.

Modified carbon fiber microelectrode (CFME) was

characterized by Fourier transform infrared-attenuated

transmittance reflectance (FTIR-ATR) spectroscopy

(Spectrum One B, Perkin Elmer, USA, with a universal

ATR attachment with a ZnSe crystal). Morphological

investigations were performed with scanning electron

microscopy (SEM) and energy dispersive X-ray analysis

(EDX) using a Carl Zeiss Leo 1430 VP, Germany.

Electrochemical impedance spectroscopy

EIS measurements were performed in 0.1 M four different

electrolytes (LiClO4, NaClO4, TEABF4 and TBABF4)/

acetonitrile (CH3CN). EIS measurements were done in

monomer-free electrolyte solution with perturbation

200 Iran Polym J (2013) 22:199–208

Iran Polymer and

Petrochemical Institute 123

amplitude of 10 mV over a frequency range between

0.01 Hz and 100 kHz with PARSTAT 2273 model

Potansiostat/galvanostat. Equivalent circuit model was

drawn the programme of ZSimpWin, version of 3.1.

Results and discussion

Electropolymerization of 3-(2-aminoethyl thiophene)

on GCE

Electropolymerization of 2AET at the glassy carbon elec-

trode has opened a field at the convergence between two

rich domains: electrochemistry of modified electrode

[53, 54] and conjugated systems [55]. Consequently, appli-

cation of modified electrodes in energy storage has been

enriched by the specific properties of intrinsically con-

ducting polymers. The cyclic voltammogram of 2AET thin

films electrochemically deposited on glassy carbon elec-

trode (GCE) recorded in 0.1 M four different electrolytes

(LiClO4, NaClO4, TEABF4 and TBABF4) as shown in

Fig. 1. The lowest oxidation potential of 2AET is *1.45 V

in 0.1 M LiClO4 (Fig. 1a) and TBABF4/CH3CN (Fig. 1c).

However, NaClO4 (Fig. 1b) and TBABF4 (Fig. 1d) have

higher oxidation potentials as *1.6 V and *1.75 V,

respectively. The highest total charges (Q = 4.22 mC)

during electro-growth process (8 cycle) was obtained in

TBABF4/CH3CN.

Effect of scan rate in monomer-free solution

A P(2AET)/GCE film was inserted into a monomer-free

electrolyte solution. Redox behavior of modified electrodes

was investigated via Randless-Sevcik equation as follows:

i ¼ 2:69� 105� �

� A� D1=2 � C0 � m1=2 ð1Þ

where, m (V s-1) is the scan rate, D (cm2 s-1) is the dif-

fusion coefficient of electro-active species, and C0 (mol/L)

is the concentration of electro-active species in solution.

Anodic and cathodic redox reaction of modified electrodes

formed in 0.1 M LiClO4, TEABF4 and TBABF4 solutions

showed both thin layer formation and diffusion controlled

process as evidenced by the linearity of the plots given in

Fig. 2. In NaClO4/CH3CN, the polymer only shows thin

layer formation due to regression fit values obtained from

current density versus scan rate graph (RAn = 0.99757 and

RCat = -0.99879) which were higher than the regression

fit values obtained from current density versus square root

of scan rate graph (RAn = 0.98788 and RCat = -0.98575)

FTIR-ATR

The FTIR-ATR spectrum of P(2AET)/CFME in 0.1 M

TBABF4/CH3CN was obtained by reflectance FTIR spec-

trophotometry (Fig. 3). The peak at 1052 cm-1 can be

attributed to dopant anion of BF4-. The peak at 2963 cm-1

is assigned to bond of C=C–H symmetric stretch in

Fig. 1 Cyclic voltammetry of

2AET on GCE in different

electrolytes of 0.1 M: a LiClO4/

CH3CN (Q = 2.93 mC),

b NaClO4/CH3CN

(Q = 2.16 mC), c TBABF4/

CH3CN (Q = 4.22 mC), and

d TEABF4/CH3CN

(Q = 2.23 mC)

([2AET]0 = 1 mM; 8 cycle;

scan rate: 25 mV s-1; potential

range: 0.0–2.0 V)

Iran Polym J (2013) 22:199–208 201

Iran Polymer and

Petrochemical Institute 123

benzene ring. The peak at 1495 cm-1 is indicated NH2

group of functional group of thiophene.

SEM

Morphology of P(2AET)/CFME was investigated via SEM

for sample obtained by cyclic voltammetry with a scan rate

of 25 mV s-1. It is not observed homogeneous thin film

due to deposition on some parts of fibers as shown in

Fig. 4.

Average values of EDX point and area analysis showed

the characteristic element analysis of Carbon (*35.12 %),

Nitrogen (*31.78 %), Fluorine (*32.8 %) and Sulfur

(*0.30 %) as shown in Table 1. EDX analysis proved us

the successfulness of electropolymerization process. And

also the existence of fluorine element into the polymer

structure gives us evidence of successfully performed

doped process.

Electrochemical impedance spectroscopy

EIS is a powerful technique to give information about the

surface configuration and capacitive behavior of modified

electrode. Among EIS plots, the more capacitive behavior

was obtained as directly proportional line with the angle of

90� from Nyquist plot, and the double layer capacitance

information was easily acquired [56]. The low frequency

capacitance values from impedance spectroscopy were

obtained from the slope of a plot of the imaginary com-

ponent (Z00) of the impedance at low frequencies versus

Fig. 2 Cyclic voltammetry of P(2AET)/GCE in monomer-free

solution in 0.1 M TBABF4/CH3CN at different initial monomer

concentrations: a [2AET]0 = 0.5 mM, b [2AET]0 = 1.0 mM, and

c [2AET]0 = 1.5 mM, 8 cycle, scan rate: 25–1000 mV s-1, potential

range: 0.0 to ?2.0 V. (Every graphics are in the same conditions on

the same line)

202 Iran Polym J (2013) 22:199–208

Iran Polymer and

Petrochemical Institute 123

inverse of the reciprocal frequency (f) (where f = 0.01 Hz)

using following equation [57]:

CLF ¼ �1 = 2p� f � Z 00 ð2Þ

The highest low frequency (10 mHz) capacitance (CLF)

value was obtained in 0.1 M LiClO4/CH3CN as CLF =

0.65, 0.64 and 0.66 mF cm-2 for the initial monomer

concentration ([2AET]0) of 0.5, 1.0 and 1.5 mM,

respectively. In 0.1 M NaClO4/CH3CN, CLF was obtained

as 0.45, 0.41 and 0.49 mF cm-2 for [2AET]0 = 0.5, 1.0

and 1.5 mM, respectively. In TEABF4/CH3CN, CLF was

calculated as 0.44 mF cm-2. And the lowest CLF values of

0.30, 0.37 and 0.35 mF cm-2 for [2AET]0 = 0.5, 1.0 and

1.5 mM in TBABF4/CH3CN, respectively (Fig. 5).

Bode-magnitude plot gives by extrapolating line to the

log Z axis at w = 1 (log x = 0) yielding the value of Cdl

from the following relationship [58]:

Zj j ¼ 1 =Cdl ð3Þ

Double layer capacitance of P(2AET)/GCE was taken

in four different electrolytes of LiClO4, NaClO4, TBABF4

and TEABF4. The highest Cdl was obtained as

*0.63 mF cm-2 in 0.1 M LiClO4/ACN for [2AET]0 =

0.5, 1.0 and 1.5 mM. The other Cdl values were obtained as

0.33, 0.32 and 0.31 mF cm-2 in 0.1 M NaClO4, TEABF4

and TBABF4, respectively (Fig. 6).

Bode-phase plot of P(2AET) was given by variation of

log (f) values. The maximum phase angles (h = 76.1� at

26.57 Hz) was obtained in 0.1 M TEABF4/ACN for

[2AET]0 = 0.5 mM. In addition, there was no so much

changes in the other electrolytes, such as in 0.1 M LiClO4/

ACN (h = 72� at 28.42 Hz) in NaClO4/ACN (h = 72.31�at 20.50 Hz) and in TBABF4/ACN (h = 73.2� at

37.22 Hz). The concentration of P(2AET) did not affect the

phase angle value through the variation of electrolyte types

as shown in Fig. 7.

The highest conductivity value (Y00 = 3.5 mS) was

observed in TEABF4/ACN. However, the lowest conduc-

tivity (Y00 = 2.7 mS) was obtained in LiClO4/ACN as

shown in Fig. 8a. In NaClO4/ACN, (Y00 = 2.6 mS) for

[2AET]0 = 0.5 and 1.0 mM, (Y00 = 1.6 mS) for [2AET]0 =

1.5 mM were obtained as given in Fig. 8b. In TBABF4/ACN,

(Y00 = 3.1 mS) for [2AET]0 = 1.0 mM, (Y00 = 2.9 mS) for

[2AET]0 = 0.5 mM, (Y00 = 2.7 mS) for [2AET]0 = 1.5 mM

were obtained from admittance plot (Fig. 8c). In TEABF4/

ACN (Y00 = 3.5 mS) for [2AET]0 = 0.5 mM was obtained as

shown in Fig. 8d.

As a result, the variation of electrolyte is more sig-

nificant than the variation of monomer. The highest

capacitance value from low frequency capacitance

Fig. 3 FTIR-ATR spectrum of 2AET/GC at [2AET]0 = 1 mM; 8

cycle; scan rate: 25 mV s-1; potential range: 0.0 to ?2.0 V; 0.1 M

TBABF4/CH3CN (Q = 60.14 mC); 30 cycle

Fig. 4 SEM analysis of a point

analysis of P(2AET) on a single

CFME at [2AET]0 = 1.0 M

potential range: 0.0 to ?2.0 V,

scan rate: 25 mV s-1, 0.1 M

TBABF4/CH3CN, 30 cycle, and

Q = 58.15 mC; b area analysis

of P(2AET) on a single CFME

at [2AET]0 = 1.0 mM,

potential range: 0.0 to ?2.0 V,

scan rate: 25 mV s-1, 0.1 M

TBABF4/CH3CN, 30 cycle, and

Q = 58.15 mC

Table 1 EDX analysis of P(2AET)/CFME

Elements/K series P(2AET)/CFME

Point analysis Area analysis

Carbon 33.51 36.74

Nitrogen 31.91 31.65

Fluorine 34.16 31.44

Sulfur 0.42 0.17

Iran Polym J (2013) 22:199–208 203

Iran Polymer and

Petrochemical Institute 123

(CLF = 0.66 mF cm-2) for [2AET]0 = 1.5 mM and double

layer capacitance (Cdl = *0.63 mF cm-2) for all electrolytes

were obtained in the electrolyte of LiClO4. The concentration

effect does not significantly influence the Cdl value.

Equivalent circuit model

The impedance spectra were analyzed in detail with

impedance plane: Nyquist (Fig. 9a), Bode-magnitude,

Fig. 5 Nyquist plots of

P(2AET)/GCE, a LiClO4/ACN,

b NaClO4/ACN,

c TBABF4/ACN, and

d TEABF4/ACN at different

initial monomer concentrations:

[2AET]0 = 0.5 mM,

[2AET]0 = 1.0 mM and

[2AET]0 = 1.5 mM

Fig. 6 Bode-magnitude plots of

P(2AET)/GCE at:

a LiClO4/ACN;

b NaClO4/ACN;

c TBABF4/ACN;d TEABF4/

ACN and different initial

monomer concentrations:

[2AET]0 = 0.5 mM;

[2AET]0 = 1.0 mM;

[2AET]0 = 1.5 mM

204 Iran Polym J (2013) 22:199–208

Iran Polymer and

Petrochemical Institute 123

Bode-phase (Fig. 9b) and admittance plots (Fig. 9c). The

results of this analysis were fitted to ZSimpwin pro-

gramme. As criteria for a good fit, the Chi-squared (v2, i.e.

the sum of the square of the differences between theoretical

and experimental points) and the relative errors were

chosen in the estimated parameters. The value of v2 was in

the range of 10-3–10-4. The equivalent circuit model of

R(Q(R(Q(R(CR))))) was given inset of Fig. 9a. R3 is in

parallel with an interfacial double layer capacitance (Cdl).

Electrolyte resistance (Rs) is in parallel connection with R1,

R2, Q1 and Q2. The constant phase element (Q) behavior of

interfaces has been ascribed to a fractal nature (especially

Fig. 7 Bode-phase plots of

P(2AET)/GCE at:

a LiClO4/ACN;

b NaClO4/ACN;

c TBABF4/ACN;

d TEABF4/ACN and different

initial monomer concentrations:

[2AET]0 = 0.5 mM;

[2AET]0 = 1.0 mM;

[2AET]0 = 1.5 mM

Fig. 8 Admittance plots of

P(2AET)/GCE at:

a LiClO4/ACN;

b NaClO4/ACN;

c TBABF4/ACN;

d TEABF4/ACN and different

initial monomer concentrations:

[2AET]0 = 0.5 mM;

[2AET]0 = 1.0 mM;

[2AET]0 = 1.5 mM

Iran Polym J (2013) 22:199–208 205

Iran Polymer and

Petrochemical Institute 123

geometry of the roughness) of the interface [59, 60]. The

admittance representation of the CPE (Q) is given by the

following equation:

YCPE ¼ Y0 jxð Þn¼ Y0x

00 � cos 1=2npð Þ þ j Y0xn � sin 1=2npð Þ ð4Þ

where Y0 and n (0 B n B 1) are frequency independent

parameters. The condition n = 0 represents an ideal

resistor, n = 0.5 A Warburg impedance, and n = -1 an

inductor. Cdl is the interfacial double layer capacitance

(high frequency surface capacitance). The Warburg

impedance is usually associated with an electrochemical

process dominated by diffusion control [61, 62]. The

highest resistance of solution and constant phase elements

(Q1 = 6.85 lS 9 s–n and Q2 = 8.95 lS 9 s–n) was

obtained for NaClO4 electrolyte as Rs = 174.4 X as shown

Fig. 9 a Nyquist plot for P(2AET)/GCE obtained from ZSimpWin

programme. Inset equivalent circuit model of R(Q(R(Q(R(CR))))),

b bode magnitude and phase plot of P(2AET)/GCE, c admittance plot

of P(2AET)/GCE (electrochemically polymerization in 0.1 M

LiClO4/ACN at [2AET]0 = 1.5 mM)

Table 2 Impedance parameter

values extracted from

ZSimpWin programme to fit the

equivalent circuit model of

R(Q(R(Q(R(CR))))) at 0.1 M

solution of four different

electrolytes (LiClO4, NaClO4,

TBABF4 and TEABF4) in

solvent of ACN for P(2AET)

coated GCE

R(Q(R(Q(R(CR))))) Electrolytes

Circuit components LiClO4 NaClO4 TBABF4 TEABF4

Rs/X 110.2 174.4 147.8 90.9

Q1/Yo (lS 9 s–n) 5.23 6.05 3.24 4.08

n 0.54 0.71 0.65 0.52

R1/X 38.64 5.86 9 105 1.23 9 102 26.68

Q2/Yo (lS 9 s–n) 4.36 8.95 1.52 2.72

n 0.88 0.84 0.92 0.91

R2/X 8.25 9 105 1.07 9 106 168.9 186.5

Cdl/F 4.33 9 10-6 1.03 9 10-6 2.63 9 10-6 3.43 9 10-7

R3/X 1.09 9 106 3.46 9 106 1.58 9 106 2.68 9 106

v2 9.27 9 10-4 5.98 9 10-3 6.90 9 10-3 4.67 9 10-4

206 Iran Polym J (2013) 22:199–208

Iran Polymer and

Petrochemical Institute 123

in Table 2. The highest (Cdl = 4.33 9 10-6 F) was

obtained in the LiClO4 electrolyte. Circuit model results

are consistent with experimental results.

Conclusion

3-(2-Aminoethylthiophene) (2AET) monomer was electro-

coated on GCE in four different electrolytes of LiClO4,

NaClO4, TBABF4 and TEABF4/ACN by CV. The char-

acterizations of modified CFMEs were performed by

FTIR-ATR, SEM-EDX, and EIS methods. The highest low

frequency capacitance (CLF = 0.66 mF cm-2) for [2AET]0 =

1.5 mM, and double layer capacitance (~0.63 mF cm-2)

for [2AET]0 = 0.5, 1.0, 1.5 mM were obtained in the

electrolyte of LiClO4. Equivalent circuit model of

R(Q(R(Q(R(CR))))) was obtained a good agreement to fit

the experimental and theoretical data.

Acknowledgments Financial support for this work by the Research

Foundation of Namik Kemal University (Turkey) project number:

NKU.BAP.00.10.AR.11.01) is gratefully acknowledged.

References

1. Heth CL, Tallman DE, Rasmussen SC (2010) Electrochemical

study of 3-(N-alkylamino)thiophenes: experimental and theoret-

ical insights into a unique mechanism of oxidative polymeriza-

tion. J Phys Chem B 114:5275–5282

2. Beaujuge PM, Amb CM, Reynolds JR (2010) Spectral engi-

neering in p-conjugated polymers with intramolecular donor-

acceptor interactions. Acc Chem Res 43:1396–1407

3. Roncali J (1992) Conjugated poly(thiophenes): synthesis, func-

tionalization, and applications. Chem Rev 92:711–738

4. McCullough RD (1998) The chemistry of conducting polythio-

phenes. Adv Mater 10:93–116

5. Koyuncu FB, Koyuncu S, Ozdemir E (2011) A new multi-elec-

trochromic 2,7-linked polycarbazole derivative: effect of the nitro

subunit. Org Electron 12:1701–1710

6. Zhang K, Tieke B, Forgie JC, Skabara PJ (2009) Electrochemical

polymerisation of N-Arylated and N-Alkylated EDOT-substituted

pyrrolo[3,4-c] pyrrole-1,4-dione (DPP) derivatives:influence of

substitution pattern on optical and electronic properties. Macro-

mol Rapid Commun 30:1834–1840

7. Irvin JA, Irvin DJ, Stenger-Smith JD (2007) Electroactive poly-

mers for batteries and supercapacitors. In: Handbook of conju-

gated polymers: processing and applications, Skotheim TA,

Reynolds JR (Eds), 3rd edn, CRC Press, Boca Raton

8. Roncali J (1999) Electrogenerated functional conjugated poly-

mers as advanced electrode materials. J Mater Chem 9:1875–1893

9. Naudin E, Ho HA, Branchaud S, Breau L, Belanger D (2002)

Electrochemical polymerization and characterization of poly(3-

(4-fluorophenyl)thiophene) in pure ionic liquids. J Phys Chem B

106:10585–10593

10. Beaujuge PM, Ellinger S, Reynolds JR (2008) The donor-

acceptor approach allows a black to transmissive switching

polymeric electrochrome. Nat Mater 7:795–799

11. Chang C-H, Wang K-L, Jiang J-C, Liaw D-J, Lee K-R, Lai J-Y,

Lai K-H (2010) Novel rapid switching and bleaching

electrochromic polyimides containing triarylamine with 2-phe-

nyl-2-isopropyl groups. Polymer 51:4493–4502

12. Goto H, Kawabata K (2011) Light driven asymmetric polymer-

ization: an approach for tele-control reaction. Polym Chem 2:

1098–1106

13. Goto H (2012) Electrochemical polymerization in crystal—

preparation of polybithiophene with crystal order. J Polym Sci

Part A Polym Chem 50:622–628

14. Kiani GR, Arsalani N, Entezami AA (2001) The influence of

the catalytic amount of 1-(2-pyrrolyl)-2-(2-thienyl)ethylene and

2-(2-thienyl)pyrrole on electropolymerization of pyrrole and

N-methylpyrrole. Iran Polym J 10:135–142

15. Tam PD, Van Hieu N (2011) Conducting polymer film-based

immunosensor using carbon nanotube/antibodies doped poly-

pyrrole. Appl Surf Sci 257:9817–9824

16. Ates M, Yilmaz K, Shahryari A, Omanovic S, Sarac AS (2008) A

study of the electrochemical behavior of poly(N-vinylcarbazole)

formed on carbon fiber microelectrodes and its response to

dopamine. IEEE Sensors J 8:1628–1639

17. Ates M, Sarac AS, Turhan CM, Ayaz NE (2009) Polycarbazole

modified carbon fiber microelectrode: surface characterization

and dopamine sensor. Fiber Polym 10:46–52

18. Ates M, Castillo J, Sarac AS, Schuhmann W (2008) Carbon fiber

microelectrodes electrocoated with polycarbazole and poly(car-

bazole-co-p-tolylsulfonyl pyrrole) P(Cz-co-p Tsp) films for the

detection of dopamine in presence of ascorbic acid. Microchim

Acta 160:247–251

19. Gomez H, Ram MK, Alvi F, Villalba P, Stefanakos E, Kumar A

(2011) Graphene-conducting polymer nanocomposite as novel

electrode for supercapacitors. J Power Sources 196:4102–4108

20. Zhou Y, Qin Z-Y, Li L, Zhang Y, Wei Y-L, Wang L-F, Zhu M-F

(2010) Polyaniline/multi-walled carbon nanotube composites

with core-shell structures as supercapacitor electrode materials.

Electrochim Acta 55:3904–3908

21. Wang J, Xu Y, Chen X, Du X (2007) Electrochemical superca-

pacitor electrode material based on poly(3,4-ethylenedioxythio-

phene) polypyrrole composite. J Power Sources 163:1120–1125

22. Selvakumar M, Pitchumani S (2010) Hybrid supercapacitor based

on poly(aniline-co-m-anilicacid) and activated carbon in non-

aqueous electrolyte. Korean J Chem Eng 27:977–982

23. Zou J, Yip H-L, Hau SK, Jen AK-Y (2010) Metal grid/conducting

polymer hybrid transparent electrode for inverted polymer solar

cells. Appl Phys Let 96:203301–203303

24. Ma C, Xu Y, Zhang C, Xu Y, Xiang W, Ouyang M (2009)

Electrochemical polymerization of a beta–beta linkages polythi-

ophene derivative based on 2,5-diphenyl-thiophene. J Electroanal

Chem 634:31–34

25. Borrelli DC, Barr MC, Bulovic V, Gleason KK (2012) Bilayer

heterojunction polymer solar cells using unsubstituted polythio-

phene via oxidative chemical vapor deposition. Sol Energ Mat

Sol C 99:190–196

26. Sivaraman P, Mishra SP, Bhattacharrya AR, Thakur A, Shas-

hidhara K, Samui AB (2012) Effect of regioregularity on specific

capacitance of poly(3-hexylthiophene). Electrochim Acta 69:

134–138

27. Anglin TC, Speros JC, Massari AM (2011) Interfacial ring ori-

entation in polythiophene field-effect transistors on functional-

ized dielectrics. J Phys Chem C 115:16027–16036

28. Jonas F, Schrader L (1991) Conductive modifications of polymers

with polypyrroles and polythiophenes. Synth Met 41:831–836

29. Kiani GR, Sheikhloie H, Rostami A (2011) Highly enhanced

electrical conductivity and thermal stability of polythiophene/

single-walled carbon nanotubes nanocomposite. Iran Polym J

20:623–632

30. Bushueva AY, Shklyaeva EV, Abashev GG (2009) New pyrim-

idines incorporating thiophene and pyrrole moieties: synthesis

Iran Polym J (2013) 22:199–208 207

Iran Polymer and

Petrochemical Institute 123

and electrochemical polymerization. Mendeleev Commun 19:

329–331

31. Groenendaal BL, Jonas F, Freitag D, Pielartzik H, Reynolds JR

(2000) Poly(3,4-ethylenedioxythiophene) and its derivatives:

past, present and future. Adv Mater 12:481–494

32. Roncali J (1997) Synthetic principles for band gap control in

linear pi-conjugated systems. Chem Rev 97:173–205

33. Granstrom M (1997) Polym novel polymer light-emitting diode

designs using poly(thiophenes). Polym Adv Technol 8:424–430

34. Higgins TB, Mirkin CA (1998) Model coordination complexes

for designing poly(terthiophene)/Rh(I) hybrid materials with

electrochemically tunable reactivities. Chem Mater 10:1589–

1595

35. Jadamiec M, Lapkowski M, Matlengiewicz M, Brembilla A,

Henry B, Rodehuser L (2007) Electrochemical and spectro-

electrochemical evidence of dimerization and oligomerization

during the polymerization of terthiophenes. Electrochim Acta

52:6146–6154

36. Chan HSO, Ng SC (1998) Synthesis, characterization and

applications of thiophene-based functional polymers. Prog Polym

Sci 23:1167–1231

37. Barbarella G, Melucci M, Sotgiu G (2005) The versatile thio-

phene: an overview of recent research on thiophene-based

materials. Adv Mater 17:1581–1593

38. Jen K-Y, Miller GG, Elsenbaumer RL (1986) Highly conducting,

soluble, and environmentally-stable poly(3-alkylthiophenes).

J Chem Soc Chem Commun 17:1346–1347

39. Armelin E, Bertran O, Estrany F, Salvatella R, Aleman C (2009)

Characterization and properties of a polythiophene with a

malonic acid dimethyl ester side group. Eur Polym J 45:2211–2221

40. Scully JR, Silverman DC, Kendig MV (1993) Electrochemical

impedance: analysis and interpretation. ASTM Int, Philadelphia

41. Darowicki K, Kawula J (2004) Impedance characterization of the

process of polyaniline first redox transformation after aniline

electropolymerization. Electrochim Acta 49:4829–4839

42. Baldissera AF, Freitas DB, Ferreira CA (2010) Electrochemical

impedance spectroscopy investigation of chlorinated rubber-

based coatings containing polyaniline as anticorrosion agent.

Mater Corros 61:790–801

43. Wang X, Bernard MC, Deslouis C, Joiret S, Rousseau P (2010) A

new transfer function in electrochemistry: dynamic coupling

between Raman spectroscopy and electrochemical impedance

spectroscopy. Electrochim Acta 55:6299–6307

44. Jannakoudakis PD, Pagalos N (1994) Electrochemical charac-

teristics of anodically prepared conducting polyaniline films on

carbon fiber supports. Synth Met 68:17–31

45. Ferloni P, Mastragostino M, Meneghello L (1996) Impedance

analysis of electronically conducting polymers. Electrochim Acta

41:27–33

46. Simoes FR, Pocrifka LA, Marchesi LFQP, Pereira EC (2011)

Investigation of electrochemical degradation process in polyani-

line/polystyrene sulfonated self-assembly films by impedance

spectroscopy. J Phys Chem B 115:11092–11097

47. Agrisuelas J, Gabrielli C, Garcıa-Jareno JJ, Gimenez-Romero D,

Perrot H, Vicente FJ (2007) Spectroelectrochemical identification

of the active sites for protons and anions insertions into poly

(azure a) thin polymer films. J Phys Chem C 111:14230–14237

48. Amemiya T, Hashimoto K, Fujishima A (1993) Faradaic charge-

transfer with double-layer charging and/or adsorption related

charging at polymer-modified electrodes as observed by color

impedance spectroscopy. J Phys Chem 97:9736–9740

49. Agrisuelas J, Garcıa- Jareno JJ, Gimenez-Romero D, Vicente F

(2010) An approach to the electrochemical activity of poly-

(phenothiazines) by complementary electrochemical impedance

spectroscopy and Vis-NIR spectroscopy. Electrochim Acta 55:

6128–6135

50. Manickam A, Chevalier A, McDermott M, Ellington AD, Hassibi A

(2010) A CMOS electrochemical impedance spectroscopy (EIS)

biosensor array. IEEE Trans Biomed Circuits Syst 4:379–390

51. Edge S, Charlton A, Varma KS, Hansen TK, Underhill AE,

Kathirgamanathan P, Berger J, Simonson O (1993) The prepa-

ration and properties of maleimide derivatives of 3-(2-amino-

ethyl)thiophene. Synth Met 53:315–324

52. Era M, Yoneda S, Sano T, Noto M (2003) Preparation of

amphiphilic poly(thiophene)s and their application for the con-

struction of organic-inorganic superlattices. Thin Solid Films

438:322–325

53. Murray RW, Ewing AG, Durst RA (1987) Chemically modified

electrodes: molecular design for electrocatalysis. Anal Chem

59:379–390

54. Anson FC, Ni CL, Saveant JM (1985) Eelectrocatalysis at redox

polymer electrodes with separation of the catalytic and charge

propogation roles. Reduction of O2 to H2O2 as catalyzed by

cobalt (II) tetrakis (4-N-methylpyridyl)porphyrin. J Am Chem

Soc 107:3442–3450

55. Skotheim TA, Reynolds J (eds) (2007) Hanbook of conducting

polymers, vols 1 and 2, 3rd edn. CRC Press, Boca Raton

56. Ding KQ, Wang Q, Jia Z, Tong R, Wang X, Shao H (2003)

Impedance description of the effect of the polar potential on a

Schiff base self-assembled monolayer. J Chin Chem Soc 50:

387–394

57. Sarac AS, Gilsing H-D, Gencturk A, Schulz B (2007) Electro-

chemically polymerized 2,2-dimethyl-3,4-propylenediox-

ythiophene on carbon fiber for microsupercapacitor. Prog Org

Coat 60:281–286

58. Sezer E, Ustamehmetoglu B, Sarac AS (1999) Chemical and

electrochemical polymerization of pyrrole in the presence of

N-substituted carbazoles. Synth Met 107:7–17

59. Bates JB, Wang JC, Anderson RL (1984) In: Proceedings of the

ECS Fall meeting, extented abstracts, New Orleans, 84:233–237

60. Le Mehaute A, Crepy G (1993) Introduction to transfer and

motion in fractal media: the geometry of kinetics. Solid State

Ionics 9–10:17–30

61. Tanguy J, Baudoin JL, Chao F, Costa M (1992) Study of the

redox mechanism of poly-3-methylthiophene by impedance

spectroscopy. Electrochim Acta 37:1417–1428

62. Refaey SAM (2004) Electrochemical impedance studies on the

electrochemical properties of poly(3-methylthiophene) in aque-

ous solutions. Synth Met 140:87–94

208 Iran Polym J (2013) 22:199–208

Iran Polymer and

Petrochemical Institute 123