Post on 04-May-2018
Final Report of Minor Research Project
Titled
DEVELOPMENT OF FLY ASH /POLYMER COMPOSITES FORELECTRRONIC MATERIALS APPLICATIONS
UGC Reference No: File No. 47-1337/10(WRO)
Submitted by
Dr. A. D. DahegaonkarDepartment of Physics
N. S. Science & Arts College Bhadrawati Dist: Chandrapur
Maharashtra State
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1. INTRODUCTION
1.1 Conducting polymers
A polymer (materials containing a long chain of molecular structures) is first and
foremost an insulator. The idea that polymers or plastics could conduct electricity is considered
absurd. In fact these materials are commonly used for surrounding copper wires and
manufacturing the outer structures of electrical appliances that prevent human from coming in
direct contact with electricity.
Approximately three decades ago, scientists discovered that a type of conjugated polymer called
‘polyacetylene’ could become highly electrically conductive after undergoing a structural
modification process called doping. The polymer is called a ‘conjugated polymer’ because of the
alternating single and double bonds in polymer chain. The de-localized electrons may move
around the whole system and become the charge carriers to make them conductive. This polymer
can be transformed into a conducting form when electrons are removed from the backbone
resulting in added to the backbone resulting in anions. Anions and cations act as charge carriers,
hopping from one site to another under the influence of an electrical field, thus increasing
conductivity.
1.2 Polyaniline
Among the conducting polymers, polyaniline has attracted a considerable scientific
interest in recent decades because of its diverse structure, low cost, good electrical properties and
wide application in different field, such as microelectronics, corrosion protection, sensor and
electrodes for batteries. Since these conducting polymer are usually obtained as power, they are
difficult to process.
1.3 Poly (o-anisidine) The practical applications of polyaniline have been limited due to harsh chemical conditions in the
synthesis and purification procedure that often lead to an inflexible polymer. To address this problem and
improve processability, a diverse set of modified polymerizations have been investigated.
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1.4 Poly (o-toluidine)
Much attention of many researchers is due to its ease of synthesis, processibility, good
thermal stability and good environmental stability. MacDiarmid investigated Poly (o-toluidine)
as an electrically conducting polymer, which is emerging as a promising synthetic metal. The
possibility of synthesizing and doping of Poly (o-toluidine) with photonic acid dopants
containing different types of counter ions is one of the key factors responsible for the versatility
of this class of polymers. Photoluminescent organic molecules are a new class of compounds
with interesting properties. They undergo emission over a wide range from the violet to the red.
They can also be combined in several different forms to produce white light. One category of
organic material with photoluminescence properties is conjugated organic polymers .
1.5 Fly ash
Fly ash, a waste product of coal combustion in thermal power plant, contains many
hazardous substances such as heavy metals and toxic organic compounds and thus is a major
source for environment pollution. Currently in China a small percentage of this waste is mainly
utilized for the manufacture of concrete, cement and brick products, and the remainder being
directly buried in fly ash ponds or landfills, which is an unsatisfactory solution both from the
ecological and economical points of view. As a consequence, new economical and reliable means
have to be found out in order to safeguard the environment and provide useful way for its
disposal. Because the fly ash contains large amount of SiO2 and Al2O3, which are main glass
network formers, many research and development investigations recently have been conducted in
its utilization as a starting material for glass and glass-ceramic production.
1.6 Literature Review
Conductive polymers such as polypyrrole, Polyacetylene, etc continue to be the
focus of active research in diverse fields including electronics, energy storage catalysis,
chemical sensing and optochemistry. Polyaniline is unique among conducting polymers
in its wide range of electrical, electrochemical and optical properties as well as good
stability. Polyaniline can be doped to highly conducted state by protonic acids or by
electrochemical methods and show moderate conductivity upon doping. In literature
survey the invention of conducting polymers has been carried into various aspects such as
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Developments in the field of conducting polymers, Development of Polyaniline,
Synthesis, Properties, Recent trends.
Fig.1.1 Books purchased under M.R.P.
2. SYNTHESIS
There are different methods by which conducting polymers can be synthesized.
Conducting polymers can be synthesized in the presence of different protonic acid media by
different methods. The most widely accepted methods are chemical oxidative polymerization
method and electrochemical method Chemical oxidative method is preferred over
electrochemical polymerization because of its cost effectiveness and bulk quantity of the
polymer that can be prepared during the onset of the reaction. Other techniques include solid
state polymerization, plasma polymerization, precursor polymer route, template polymerization.
In present investigation deals with the synthesis of conducting polymer polyaniline,
poly(o-anisidine), poly(o-toulidine) and its composites with various weight percentage of fly ash.
These composites have the ability to enhance their material properties with desirable mechanical
and physical characteristics. One way of making these composites involves synthesizing the
conductive polymer inside the matrices of conventional polymers using chemical or
electrochemical polymerization.
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Fig. 2.1 Weight Balance Fig. 2.2 Synthesis process
Fig. 2.3 Hot Air Oven Fig. 2.4 Prepared Samples
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.There are many reports pertaining to the chemical preparation of conductive polymer
composites without using any insulating polymer. The most preferred method for synthesis of
PANI composites is to use either HCL or H2SO4 with ammonium peroxydisulfate as an oxidant.
In these approaches monomer is polymerized in the presence of commercially available
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inorganic acid particles which act as colloidal substrate for the precipitating polymer nuclei
leading to the formation of conducting polymer-inorganic oxide composites .Among different
conducting polymers polyaniline is chosen as a matrix polymer because of its high stability, easy
processability,low cost and wide utility.
3. CHARACTERIZATION
Characterization of a material is an important step after its synthesis because it gives
useful parameters in determining the properties of polymers. The characterization of conducting
polymer composites required various lab techniques which are to be used to determine the
structure and properties. Chemical characterizations required to determine the oxidation states.
Physical characterization consists of spectroscopic analysis using Fourier Transform Infra Red
(FT-IR) and UV-visible spectrophotometer; structural analysis using X-Ray Diffraction (XRD)
and Scanning Electron Microscopy (SEM); thermal analysis using Thermogravimtric Analysis
(TGA), Thermal Differential Analysis (DTA) and Differential Scanning Calerometry (DSC).
Physico-chemical methods involve the application of electroanalytical techniques like Cyclic
Voltammetry (CV). \
A single method may not provide much information, but a combination of two or three
methods can give us fairly good knowledge about structure of conducting polymer
semiconductor composites. In present investigation, the following useful techniques have been
used to investigate the synthesized materials.
Scanning Electron Microscopy
UV - visible spectroscopy
X-Ray Diffraction
Fourier Transform Infra Red
The aim of the present chapter is to explore the composition of synthesized conducting
polymer fly ash composites by using these techniques and each technique has been well
explained with introduction, theoretical aspects and finally results and discussion came out from
the analysis.
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4. ELECTRIC AND DIELECTRIC PROPERTIES
4.1 Conductivity Measurement
The electrical conductivity of polyaniline, poly(o-anisidine), poly(o-toulidine), FA and its
composites with various weight percentage of FA measurements were carried out in
Department of physics N S Science & Arts College Bhadrawati by four probe resistivity
measurement setup as shown in figure 4.2.The whole four probes set-up consist of separate three
units Model produced by Scientific Equipment Roorkee. Four probe set up consist of separate
three units.
Fig. 4.1: Experimental set up of the Four-Probe method
4.2 Dielectric Properties: Dielectric constant measurement are one of the most popular
methods of evaluating solid materials, such as electric insulators and polymers, because
dielectric constant measurement can be performed easier than chemical analysis techniques. We
can evaluate not only the electrical characteristics, but also the physical characteristics, the
structure of elements and their density can be derived from measured dielectric constant
information.
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5. FUTURE SCOPE OF THE WORK
Conducting polymers are becoming of increasing important for a variety of applications.
However, still more research is needed to ascertain their use in sensors,electronic devices,
photovoltaic devices, electroluminescence, molecular electronics, as catalyst supports low
conducting coatings for high voltage transmission cables and for the anodic protection of steel
against corrosion. Moreover, there is very great potential to use them in the virtually unexplored
biomedical applications. Another versatile area from the technological point of view is the
studies on composites containing conducting polymers and an inert polymer matrix.
Fly ash utilization is being promoted as an "eco-friendly solution". It is certainly a use of
an otherwise useless and potentially hazardous waste. We have not found any data to indicate any
environmental problems with fly ash utilization. This could be a result of inadequate focus on the
problem, But nor have we found any data that actually absolves fly ash products of potential
environmental contamination. In fact, most proponents of fly ash products do not seem to have
given this aspect any serious thought. Studies examining the environmental and health effects
due to leachates from such applications are hard to come by. ``At the moment we are in the
process of studying whether utilization of fly ash will have any human health or environmental
effects or not. We are generating data for 3 years after which we can confidently say that fly ash
is environment friendly’’ says Vimal Kumar Director of Fly Ash Mission.
For a number of meaningful applications, electrical conductivity is potentially one of the most
important properties of a material. Usually, raw FA is rich in aluminosilicate materials(mullite,
quartz, and alumina) and has a high electrical resistivity of the order of 1011-1012Ω.cm or even
higher. In comparison, porcelain, which is made from aluminosilicate materials (clay, quartz,
alumina and feldspar) too, and is used in the high-tension ceramic insulators, has an electrical
resistivity of the order of 1013Ω.cm. This implies that FA can possibly be used as a raw material
in high-tension insulators applications, although not much work has been done along this
direction. On the other hand, based on the requirements, the electrical properties of FA can be
significantly modified, for example, by blending it into composites of suitable material, such as a
conducting polymer. FA showed dielectric constant of the order of 10 which can be best suitable
material for capacitor fabrication and the samples of fly ash is of great scientific and
technological interest.
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6. REFERENCES
[1] Bernard M C, Joiret S, Hugot-Le Goff A, Viet Phong P, Protection of iron against
corrosion using a polyaniline layer. I. Polyaniline electrodeposit, J Electrochem Soc, 148,
(2001) 12-16.
[2] Leclerc M, Guay J, Dao LH, Synthesis and characterization of poly(alkylanilines),
Macromolecules, 22 (1989) 649-683,
[3] De Armitt C, Armes SP, Winter J, Urbe FA, Gottesfeld S, Mombourquette C, Anovel N-
substituted polyaniline derivative, Polymer, 34 (1993) 158- 162
[4] A. G. MacDiarmid, R. I. Mammone, J. R. Krawczyk and S. J. Porter, “Advanced
Electronic and Photonic Materials and Devices,” Molecular Crystals and Liquid Crystals,
Vol. 105 (1984) 89-105.
[5] Kiran Kumari1, Vazid Ali1, Gita Rani1, Sushil Kumar2, G. B. V. S. Lakshmi3, M.
Zulfequar; Materials Sciences and Application, (2011) 2 1049-1057
[6] Hua Shao. Kaiming Liang, Feng Zhou, Guoliang Wang, Fei Peng Journal of Non-
Crystalline Solids 337 (2004) 157–160
[7] A.G. MacDiarmid, J.H. Chiang, M. Halpem, W.S. Hung, S.L. Mu, N.L.D. Somosiri, W.
Wu and S.I. Yaniger., Mol. Cryst. Liq. Cryst121(1985)173.
[8] W.S. Huang, B.D. Humphery and A.G. MacDiarmid., J. Chem. Soc. Farady Trans.
182(1986) 2385
[9] Y. Cao, P. Smith and A.J. Heeger., Synth. Met.48(1992)91
[10] Y. Cao, A. Anadreatta, A.J. Heeger and P. Smith., Polymer, 30,(1989) 2305
[11] M. Umana and J. Waller., Anal. Chem., 58(1986) 2979
[12] P.N. Bartlett and R.G. Whitaker., J. Electroanal. Chem.224,(1987)27
[13] N.C. Foulds and C.R. Lowe., J. Chem. Soc. Farady Trans-1, 82(1986) 1259
[14] H. Schumann, H.T. Chiba and M. Aizawa., Sensors and Actuators, 13(1988) 79
[15] J.E. Frommer and R.R. Chance, “Encyclopedia of Polymer Sciences and Engineering”,
edited by J.I. Kroschwitz; Wiley, New York (1986)462
[16] S.S. Roth., Material Science Forum, 21(1987)10
[17] N.S. Murthy, L.W. Shacklette and R.H. Baughmann, J. Chem. Phys, 87, (1987) 2346
[18] S C Raghavendra, Syed Khasim, M Revanasiddappa, M V N Ambika Prasad and A BKulkarni. Bull. Mater sci., Vol. 26 No. 7 December 2003 733-739
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