Materials Sciences and Applications, 2010, 1, 253-259
doi:10.4236/msa.2010.14037 Published Online October 2010 (
Copyright © 2010 SciRes. MSA
Polypyrrole Coated PET Fabrics for Thermal
Amelia Carolina Sparavigna1, Luca Florio2, Jamshid Avloni3, Arthur Henn4
1Physics Department, Politecnico di Torino, Torino, Italy; 2Laboratorio Tessili Innovativi, Biella, Italy; 3Eeonyx Corporation, Pinole,
USA; 4Marktek Inc., Chesterfield, USA.
Received July 7th, 2010; revised July 26th, 2010; accepted July 27th, 2010.
Polypyrrole can be chemically synthesized on PET fabrics, giving rise to textiles with high electric conductivity. These
textiles are suitable for several applications from antistatic films to electromagnetic interference shielding devices.
Here we discuss the thermal-electric performance and the heat generation of polypyrrole coated PET fabric samples,
previously studied because of their electric conductivity and electromagnetic interference shielding effectiveness. The
measured Seebeck effect is comparable with that of metallic thermocouples. Since polypyrrole shows extremely low
thermal diffusivities regardless of the electrical conductivity, the low thermal conductivity gives significant advantage
to the thermoelectric figure-of-merit ZT, comparable with that of some traditional inorganic thermoelectric materials.
The heat generation is also investigated for possible heating textile devices. The results confirm polypyrrole as a prom-
ising material for thermal electric applications due to its easy preparation in low cost processing.
Keywords: Conductive Polymers, Polypyrrole, Thermoelectric Materials
1. Introduction
In the late 1970s, MacDiarmid, Heeger and Shirakawa
discovered how to get polymers conducting electricity.1
The first material becoming an intrinsically conducting
polymer (ICP) was polyacetylene, after a doping with
iodine. The announcement of this discovery quickly re-
verberated around scientific community, and intensity of
the research for other conducing polymers magnified
dramatically [1-3]. A new generation of polymers was
then developed, exhibiting the electrical and optical pro-
perties of metals or semiconductors, at the same time
retaining the attractive mechanical properties and proc-
essing advantages of polymers.
Intrinsically conducting polymers were immediately
seen as a new route to mimic metallic conductivity, be-
sides the well-know approach to insert conductive fillers
into an inherently insulating resin, or to coat a plastic
substrate with a conductive metal solution [4]. In this
manner, conductive fibers can be prepared to obtain
conductive fabrics, or, fabrics already produced can be
metalized with a conductive coating. By the way, let us
note that metal coated textiles remain fundamental mate-
rials, because they generally show a high electromagnetic
interference shielding effectiveness (EMI-SE) [5,6].
In fact, intrinsically conducting polymeric materials
can be used to obtain rather innovative textiles [6]. These
textiles are able to absorb as well as reflect electromag-
netic waves, and then can exhibit certain advantages over
metallic materials. Actually, the most prominent ICPs in
EMI-SE are polypyrrole and polyaniline, where electrical
conductivity can have values comparable to those ob-
served for poorly conducting metals and alloy [5-8].
Among the first commercial products incorporating
polypyrrole there was Contex®, a conductive textile pro-
duct originally manufactured by Milliken [9], starting
around 1990, and now produced by Eeonyx Corp., as
EeonTex™. An early application, involving the coating
of polyester fibers with polypyrrole (PPy) was the crea-
tion of an antistatic fabric. Here, we will show the re-
sults of measurements of thermal electric properties of
the PPy-coated EeonTex. In particular, we deduce its
Seebeck coefficient, which turns out to be comparable
with that of metal thermocouple materials. Because
polypyrrole shows extremely low thermal diffusivity, the
value of the figure-of-merit turns out to be of the same
1The Nobel Prize in Chemistry 2000 was awarded jointly to Alan J.
Heeger, Alan G. MacDiarmid and Hideki Shirakawa “
or the discovery
and development of conductive polymers”.
Polypyrrole Coated PET Fabrics for Thermal Applications
Copyright © 2010 SciRes. MSA
order of magnitude of some traditional inorganic ther-
moelectric materials [10].
Thermoelectric effects in ICPs are deserving a special
attention, due to the considerable effort actually paid to
have thermoelectric effects from low-weight but high-
reliable materials. The reason is that the thermoelectric
cooling is a good strategy in semiconductor electronics
operating at high frequencies, where the thermal man-
agement becomes crucial. Let us remember that, accord-
ing to Kelvin relations between Seebeck and Peltier co-
efficients, an evaluation of the Seebeck effect allows
estimating the cooling power of materials.
The target of this paper is then in investigating the
thermoelectric effects in PPy coated samples, which have
been previously studied from the point of view of their
electric conductivity and electromagnetic interference
shielding effectiveness [5,6], We will also discuss the
heat generation obtained from PPy coated fabrics, for
suitable applications in textile heating systems. Polypyr-
role is in fact one of ICPs very promising for wide ther-
mal electric applications because of its easy preparation
with a low cost processing.
2. Samples Preparation
A PPy coated textile could represent a possible solution
for heating and cooling and for temperature monitoring.
As previously told, one of the first commercial textile
products incorporating conductive polypyrrole was the
Contex conductive textile. This textile evolved in a new
material, with a modified PPy coating, more conductive
and thermally stable. While imparting electrical conduc-
tivity and a dark color to the substrates, the PPy coating
process barely affects the strength, drape, flexibility, and
porosity of the starting substrates.
For the measurements discussed in this paper, we used
an EeonTex PPy-coated PET fabric which was prepared
similarly as described previously in [11,12], with raw
chemicals purchased from Sigma-Aldrich and used with-
out further purification. Stochiometric molar ratio of or-
ganic acid dopant, anthraquinone-2-sulfonic acid to pyr-
role-monomer (i.e., 0.33:1) was used to ensure complete
doping level. The molar ratio of polymerisation catalyst,
iron (III) nitrate, to monomer (pyrrole) equal to 2.3 mol/
mol was used for all reactions. The macroscopic texture
of this fabric is shown in Figure 1: it is a net with a
structure quite useful for application in heating systems,
as we shall demonstrate in Section 4 of this paper.
Simultaneous in-situ polymerization and deposition of
conductive polypyrrole leads to production of conductive,
smooth and uniform coating with thickness under 1 m,
according to transmission electronic microscope meas-
urements (see Figure 2). As observed in Ref. 13, it is
possible a formation of insoluble polymers in the bulk
Figure 1. Polypyrrole coated PET net. The image sizes are
4.3 cm
5 cm.
solution and on the surface of the substrate simultaneously.
The bulk polymerization produces dendritic polymer
particles in the solution and the surface polymerization
forms a polymer film on the substrate surface. Some of the
bulk polymer precipitates on the surface of the substrate
and then the SEM analysis shows these particles on the
Figures 3 and 4 are reproducing scanning electron
microscope SEM images of PPy coated fibers in a non-
woven textile sample and in a twill textile sample, re-
spectively. These materials possess a good conductivity
and then are quite useful for electromagnetic shielding
applications, as reported in Ref. 5 and 6. In that paper,
the performances of PPy coated fabrics were compared
with that of a leno nylon fabric, metalized with a Ni/Ag
In the following section we will discuss the Seebeck
effect of the PPy-coated net shown in Figure 1 and of the
leno Ni/Ag metalized textile, for comparison. For what
concerns the heat generation, this will be discussed in
Section 4 for the PPy coated net. The metalized leno
sample is not useful due to its low resistance. In fact, the
PPy/PET net has a DC surface resistivity of 306.0 /sq,
whereas the metalized leno has a resistance of 0.22 /sq.
The electrical DC surface resistances were measured by
using a four-in-line point probe in combination with
computerized Loresta-AP meter from Mitsubishi Petro-
chemical Co., LTD.
3. Thermal-Electric Effects
Researches on organic materials for thermoelectric ap-
plications have not been so attractive, probably because
of their poor electronic transporting characters, till the
Polypyrrole Coated PET Fabrics for Thermal Applications
Copyright © 2010 SciRes. MSA
Figure 2. Scanning electron microscope SEM images of the
PPy-coated PET net shown in Figure 1. The dust is due to
polymer particles in solution, deposited on the fibers of the
net. In the lower panel of the image a detail of fibers.
discovery of ICPs. Some of these electrically conducting
polymers have gained attention because of their consid-
erable thermal stability. These materials, which are poly-
aniline and polypyrrole, are considered suitable for ap-
plications to electronic devices and sensors [14-17].
For thermal sensors, a systematic investigation on ther-
moelectric performances of polyaniline [18] and poly-
pyrrole [19] is then interesting. In fact, supposing for
polymeric compounds a low thermal conductivity, we can
obtain significant advantage of the thermoelectric fig-
ure-of-merit. Let us remember that the figure-of-merit is
defined as 2/
(), where S, , and T are
Seebeck coefficient, electric conductivity, thermal con-
ductivity, and absolute temperature, respectively. The
value of
T for polypyrrole is comparable with that of
Figure 3. SEM images of PPy coated fibers in a nonwoven
textile sample.
Figure 4. SEM images of PPy coated fibers in a twill textile
some traditionally used inorganic thermoelectric materi-
als [8,16]. Besides polyaniline and polypyrrole, other
materials, such as polythiophene has been recently invest-
tigated, in the form of nanofilms too [20-21].
We investigated the behavior of the electrical resistive-
ity as a function of temperature. Starting from room tem-
perature, the resistance of a PPy/PET sample placed in a
Polypyrrole Coated PET Fabrics for Thermal Applications
Copyright © 2010 SciRes. MSA
thermostage, was checked till a temperature of 70. The
resistance behavior with temperature is typical of a semi-
conductor with the resistance decreasing linearly as the
temperature increases. At room temperature, the resis-
tance was of 172 in a sample with a length of 4 cm,
composed by 10 yarns, each yarn with a diameter of 0.05
cm. At 70°C, the resistance of the sample was of 145 .
Assuming as in Ref. 23 a thickness in polypyrrole coat-
ing of around 1 m, the electric conductivity
out to be 411
10 m
. This estimation of the electrical
conduc- tivity of PPy coating is in good agreement with
the value of 411
1.7 10m
 , given in Ref. 17.
Thermoelectric Seebeck coefficient (S) and its tem-
perature dependence were determined by connecting a
stripe of PPy/PET net 0.5 cm wide with a copper wire.
The two materials are electrically connected by the pres-
sure of a very small silver clip, insulated from the junc-
tion. The hot junction was placed in the thermostage with
a reference Chromel/Alumel thermocouple and the cold
junction between the PPy/PET stripe and copper was
thermally anchored at room temperature (26). The same
anchoring was used for the cold junction of the Chro-
mel-Alumel thermocouple (a diagram of the experiment-
tal set-up in Figure 5). Variations in monitored room
temperature during measurements were negligible (around
In Figure 6, the behavior of the electro-motive force
measured for two such PPy/Copper thermocouples is
given as a function of temperature difference T
tween the actual hot junction temperature and the room
temperature. Assuming a value of Copper e.m.f. vs. Pla-
tinum of 0.0076 mV/K [24], we can estimate a value of
0.0133 mV/K for the PPy vs. Platinum e.m.f. and posi-
To obtain the figure-of-merit (
T), we estimate the
PPy thermal conductivity in the following manner. Ther-
mal diffusivity of PPy films was deduced from meas-
urements by the laser flash method [25]. In Ref. 25, PPy
films exhibit a thermal diffusivity ranging from 4 to
8.10m s
at room temperature (even lower than the
value of 621
1.310m s
measured for polyaniline [26]).
The very low thermal diffusivity of polypyrrole films is
originated in the lattice structure, in particular from a
dominant amorphous character of the chain structure. An
amorphous structure strongly reduces the thermal phonon
transport, because strong phonon scattering mechanisms
appear [27,28].
We can then assume a value of thermal diffusivity
of about 721
5.10m s
and a specific heat capacity
0.4J gKc
, in the range of the values for organic
polymers [26]. The thermal conductivity is then given by
. With a density
of 33
1.310kg/ m [29],
the thermal conductivity of polypyrrole film turns out to
Figure 5. Diagram of the experimental set–up for measur-
ing the Seebeck effect. The electromotive force of two ther-
mocouples are compared: a thermocouple is used as a ref-
erence to determine the temperature in the thermostage, the
other to determine the unknown electromotive force of the
Figure 6. Electromotive force measured for a PPy-PET/
Copper thermocouple as a function of the temperature dif-
ference T between the actual hot junction temperature
and the room temperature. The figure reports two diffeent
scanning in temperature.
be 11
0.3W mK
. This low thermal conductivity is at
least in one order of magnitude lower than that of the best
inorganic thermoelectric materials. Using 411
10 m
 ,
0.3W mK
and our estimate of Seebeck coeffi-
cient, we obtain 3
1.5 10ZT
 at 300 KT in agree-
ment with data of polypyrrole films [17].
The power factor 2
is approximately 6
2. 10
. This power factor is better than those reported
for polypyrrole in Ref. 30.
Note from Figure 6 the linear behaviour of the ther-
moelectric power with respect to temperature: this be-
haviour has been observed in highly doped polyacetylene
and in some cases for PANi [30].
Investigations of the electromotive forces with non-
woven and twill samples of Figures 3 and 4 were also
performed, but in this case, the results of measurements
are questionable due to a strong dependence on the contact
between textile and wires. The best result we obtained was
Polypyrrole Coated PET Fabrics for Thermal Applications
Copyright © 2010 SciRes. MSA
of 0.008 mV/K for the non-woven sample, with a linear
behavior with temperature. The nonwoven sample had a
DC surface resistivity of 30.0 /sq: we could estimate a
quite optimistic value of the electric conductivity
10 m
. Assuming the value 0.005 mV/K as a possi-
ble estimate of Seebeck coefficient, we could reach a
power factor 2
of 512
0.510W mK
, and a fig-
ure-of-merit 3
4.8 10ZT
 at a temperature of
300 KT.
The Seebeck electromotive force of the nylon leno
sample, coated Ni/Ag, connected with Cu was also mea-
sured and the behavior is shown in Figure 7 (curve b).
The same figure shows that a thermocouple built with
Ni/Ag/Nylon and PPy/PET can give the higher electro-
motive force (curve a). We have also prepared a thermo-
couple with PPy/PET and a yarn composed of comer-
cial carbon fibers (curve c).
As shown by the measurements here reported, PPy
coating can be successfully used with other conductive
yarns, for instance Copper, Ni/Ag coated yarns or carbon
fibers, to obtain stable textile thermopiles, which are able
to provide thermo-powers as typical semiconductors. The
proposal of use coated fabrics in thermal-electric devices
is not new [31]. Let us remark that we used a commercial
PPy-coated textile, with a stable coating, not an ad-hoc
prepared film, and this, in our opinion, is relevant for
industrial applications.
4. Heat Generation from Fabrics
A possible application of the PPy-coated net, due to its
fabric structure, is in heating devices. The following set-
up for detecting heat generation is used [32,33]. This
set-up was previously developed to study polypyrrole
samples prepared in Biella laboratory for innovative tex-
tiles. Those samples were too dusty to allow them to be
used in applications. An adjustable Variac power supply
was used to generate an AC current/voltage over the fab-
ric. Voltage and current were monitored by Keithley
voltmeter and amperometer. A square shape fabric (6 cm
6 cm) was positioned between two pressed electric
contacts (a diagram of the arrangement in Figure 8). The
temperature rise was measured using an Omega infrared
thermometer, placed to control the center of the sample.
In Figure 9, the behavior of the temperature as a func-
tion of the current is given, with the rise of the voltage.
According to the power law, the maximum theoretical
power achieved from the fabrics is: P = VI, where P is
the power developed and V,I the voltage and current. The
AC current frequency is 50 Hz. In Figure 10, the power
and the impedance as a function of current are shown.
In Ref. 12, the power density per unit area is assumed
to be: 22
PV Rl, where S
R is the surface resis-
tance and l the size of the sample. Our highest value is
Figure 7. Electromotive force measured for Ni/Ag/Nylon/
Contex. (a) for Ni/Ag/Nylon/Copper, (b) and for PPy/PET/
Carbon Fibers; (c) as a function of the temperature differ-
ence T between the actual hot junction temperature and
cold junction at room temperature.
Figure 8. Experimental set-up diagram for measuring the
heating effect of a textile. Current and voltage across the
sample must be monitored.
Figure 9. Behavior of the voltage and temperature of the
PPy coated sample as a function of the current, measured
with voltmeter and thermometer.
Polypyrrole Coated PET Fabrics for Thermal Applications
Copyright © 2010 SciRes. MSA
Figure 10. Behavior of the impedance and power developed
by the PPy coated sample as a function of the current. The
values of impedance and power are estimated from data of
Figure 8.
370 2
W/m in agreement with the value obtained in
Ref. 12.
5. Conclusions
The conversion electricity-heat has always attracted a
great attention because of applications in heaters, coolers
and thermoelectric power generators. The parameter mea-
suring the suitability of a material for these applications is
the figure-of-merit. In order to have high values of the
figure-of-merit, a material must have high charge trans-
port conductivity, high Seebeck coefficient and low
thermal conductivity. The intrinsically conducting poly-
mers can be considered as a new generation of thermoe-
lectric materials, due to their characteristic that often are
achieving a figure-of-merit comparable with that of typi-
cal semiconductors. Other attractive features are the low
cost of material resources, an easy synthesis and proc-
essing into desired forms.
Many conducting polymers have been investigated as
thermal materials, among them polyaniline, polythio-
phenes and polypyrroles. Here we have studied the prop-
erties of a commercially available polypyrrole coated
fabric. As shown by measurements, a Seebeck effect can
be achieved by using a PPy conducting coating of a PET
fabric. According to the Kelvin relation between Seebeck
S and Peltier coefficients, ST
, we can also ima-
gine a possible application in cooling devices of poly-
pyrrole coated fabrics.
We have also seen that with PPy/PET fabrics, it is
possible to easily make heating fabrics. Since the coating
with polypyrrole is possible on many different fibers [34],
the potential applications of polypyrrole in the building
of heating pads is relevant. We suggest then that PPy-
coated fabrics may be practically useful for many appli-
cations, including flexible, portable surface-heating ele-
ments for medical or other applications.
6. Acknowledgements
Authors thank Angelica Chiodoni for SEM analysis.
[1] Y. Cao, P. Smith and A. J. Heeger, “Counter-Ion Induced
Processibility of Conducting Polyaniline,” Synthetic Met-
als, Vol. 57, No. 1, 1993, pp. 3514-3519.
[2] C. K. Chiang, C. R. Fincher, Y. W. Park, A. J. Heeger, H.
Shirakawa, E. J. Louis, S. C. Gau and A. G. MacDiarmid,
“Electrical Conductivity in Doped Polyacetylene,” Phys-
ics Review Letters, Vol. 39, No. 17, 1997, pp. 1098-
[3] A. G. MacDiarmid, “Polyaniline and Polypyrrole: Where
are We Headed?” Synthetic Metals, Vol. 84, No. 1-3,
1997, pp. 27-34.
[4] J. Edenbaum, Ed., “Plastics Additives and Modifiers
Handbook,” Van Nostrand Reinhold, New York, 1992.
[5] J. Avloni, R. Lau, M. Ouyang, L. Florio, A. R. Henn and
A. Sparavigna, “Shielding Effectiveness Evaluation of
Metallized and Polypyrrole-Coated Fabrics,” Journal of
Thermoplastic Composite Materials, Vol. 20, No. 3, 2007,
pp. 241-254.
[6] J. Avloni, M. Ouyang, L. Florio, A. R. Henn and A.
Sparavigna, “Polypyrrole-Coated Nonwovens for Elec-
tromagnetic Shielding,” Journal of Industrial Textiles,
Vol. 38, No. 3, 2008, pp. 55-68.
[7] A. R. Henn and R. M. Cribb, “Modelling the Shielding
Effectiveness of Metallized Fabrics,” Interference Tech-
nology Engineering Master (ITEM) Update, 1993, pp.
[8] Y. Y. Wang and X. L. Jing, “Intrinsically Conducting Po-
lymers for Electromagnetic Interference Shielding,”
Polymers for Advanced Technologies, Vol. 16, No. 4,
2005, pp. 344-351.
[9] Milliken and Co., Milliken.
[10] A. F. Ioffe, “Semiconductor Thermoelements and Ther-
moelectric Cooling,” Infosearch, London, 1957.
[11] H. H. Kuhn and A. D. Child, “Handbook of Conducting
Polymers,” Marcel Dekker, New York, 1998.
[12] H. H. Kuhn, A. D. Child and W. C. Kimbrell, “Toward
Real Applications of conductive Polymers, Synthetic
Metals,” Vol. 71, No. 1-3, 1995, pp. 2139-2142.
[13] E. Hakansson, A. Kaynak, T. Lin, S. Nahavandi, T. Jones
and E. Hu, “Characterization of Conducting Polymer
Coated Synthetic Fabrics for Heat Generation,” Synthetic
Metals, Vol. 144, No. 1, 2004, pp. 21-28.
[14] D. Kumar and R. C. Sharma, “Advances in Conductive
Polymers,” European Polymer Journal, Vol. 34, No. 8,
1998, pp. 1053-1060.
[15] D. Braun, “Semiconducting polymer LEDs,” Materials
Today, Vol. 5, No. 6, 2002, pp. 32-39.
Polypyrrole Coated PET Fabrics for Thermal Applications
Copyright © 2010 SciRes. MSA
[16] J. V. Hatfield, P. Neaves, K. Persaud and P. Travers,
“Towards an Integrated Electronic Nose Using Conduct-
ing Polymer Sensors,” Sensors and Actuators B, Vol. 18,
No. 1-3, 1994, pp. 221-228.
[17] H. Yan, T. Ishida and N. Toshima, “Thermoelectric Prop-
erties of Electrically Conductive Polypyrrole Film, Ther-
moelectrics,” Proceedings ICT 2001, XX International
Conference on Thermoelectrics, Beijing, 2001, pp. 310-
[18] F. Yakuphanoglu and B. F. Şenkal, “Electronic and
Thermoelectric Properties of Polyaniline Organic Semi-
conductor and Electrical Characterization of Al/PANI
MIS Diode,” Journal of Physical Chemistry C, Vol. 111,
No. 4, 2007, pp. 1840-1846.
[19] A. B. Kaiser, O. Mercier, H. J. Trodahl, N. T. Kemp, C. J.
Liu, B. Chapman, A. M. Carr, R. G. Buckley, A. C. Par-
tridge, J. Y. Lee, C. Y. Kim, A. Bartl, L. Dunsch, W. T.
Smith and J. S. Shapiro, “Thermoelectric Power and Con-
ductivity of Different Types of Polypyrrole,” Journal of
Polymer Science: Part B: Polymer Physics, Vol. 37, No. 9,
1999, pp. 953-960.
[20] M. Scholdt, H. Do, J. Lang, A. Gall, A. Colsmann, U.
Lemmer, J. D. Koenig, M. Winkler and H. Boettner, “Or-
ganic Semiconductors for Thermoelectric Applications,”
Journal of Electronic Materials, Springer, Boston, 2010.
[21] Y. Shinohara, K. Hiraishi, H. Nakanishi, Y. Isoda and Y.
Imai, “Study on Thermoelectric Properties of Conductive
Polymers,” Transactions on Materials Research Society
of Japanese, Vol. 30, No. 4, 2005, pp. 963-969.
[22] B. Y. Lu, C. C. Liu, S. Lu, J. K. Xu, F. X. Jiang, Y. Z. Li
and Z. Zhang, “Thermoelectric Performances of Free-
standing Polythiophene and Poly(3-Methylthiophene)
Nanofilms,” Chinese Physics Letters, Vol. 27, No. 5, 2010,
pp. 057201.1-057201.4.
[23] A. R. Henn, “Calculating the Surface Resistivity of Con-
ductive Fabrics,” Interference Technology Engineering
Master (ITEM) Update, 1996, pp. 66-72.
[24] D. E. Gray, “American Institute of Physics Handbook,”
McGraw-Hill, New York, 1963.
[25] M. Y. Lim, W. M. M. Yunus, A. Kassim and H. N. M. E.
Mahmud, “Photoacoustic Measurement of Thermal Diffu-
sivity of Polypyrrole Conducting Polymer Composite
Films,” American Journal of Applied Sciences, Vol. 6, No.
2, 2009, pp. 313-316.
[26] H. Yan, N. Sada and N. Toshima, “Thermal Transporting
Properties of Electrically Conductive Polyaniline Films as
Organic Thermoelectric Materials,” Journal of Thermal
Analysis and Calorimetry, Vol. 69, No. 3, 1992, pp. 881-
[27] M. Omini and A. Sparavigna, “Role of Grain Boundaries
as Phonon Diffraction Gratings in the Theory of Thermal
Conductivity,” Physics Review B, Vol. 61, No. 10, 2000,
pp. 6677-6688.
[28] A. Sparavigna, M. Omini, A. Pasquarelli and A. Strigazzi,
“Thermal Diffusivity and Conductivity in Low-Con-
ducting Materials: A New Technique,” International
Journal of Thermophysics, Vol. 13, No. 2, 1992, pp. 351-
[29] J. Tietje-Girault, C. Ponce de León and F. C. Walsh,
“Electrochemically Deposited Polypyrrole Films and their
Characterization,” Surface & Coatings Technology, Vol.
201, No. 12, 2007, pp. 6025-6034.
[30] A. Shakouri and S. Li, “Thermoelectric Power Factor for
Electrically Conductive Polymers,” Proceedings of In-
ternational Conference on Thermoelectrics, Baltimore,
September 1999.
[31] E. Hu, A. Kaynak and Y. Li, “Development of a Cooling
Fabric from Conducting Polymer Coated Fibres: Proof of
Concept,” Synthetic Metals, Vol. 150, No. 2, 2005, pp.
[32] L. Florio, “Dissertation for Master Degree, Studio dei
Polimeri Intrinsecamente Conduttori: Applicazione al
tessile Elettronico (in Italian),” Politecnico di Torino,
[33] L. Florio and A. Sparavigna, “Thermoelectric Properties
of Conducting Polymers,” INF Meeting, National Con-
ference on the Physics of Matter, Genova, 2004.
[34] D. T. Seshadri and N. V. Bhat, “Synthesis and Properties
of Cotton Fabrics Modified with Polypyrrole,” Sen’I
Gakkaishi, Vol. 61, No. 4, 2005, pp. 103-108.