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TITLE
DEDICATION
CERTIFICATE
DECLARATION
ACKNOWLEDGEMENT
CONTENTS
PREFACE
1. CONDUCTING POLYMERS - AN INTRODUCTION
1.1.Introduction
1.2.Historical background of the development of conducting polymers
1.3.Mechanism of electrical conduction in conducting polymers
1.4.Chemical synthesis of conducting polymers
1.4.1. Polyacetylene
1.4.2. Polypara phenylene sulphide
1.4.3. Polypara phenylene
1.4.4. Polypyrrole
1.5.Electrochemical synthesis
1.6.Doping methods
1.7.Effect of doping on polymers
1.8.Stable and processable conducting polymers
1.9Electrochemical property-Cyclic voltammetry
1.10.Progress towards technology
1.11.Work undertaken in the present study
References
2. PREPARATION AND CHARACTERIZATION OF CONDUCTING POLYPYRROLES
2.1.General introduction
2.2.Chemical oxidative polymerization of polypyrrole
2.3.Electrochemical polymerization of polypyrrole
2.4.Mechanism of electrochemical polymerization
2.5.Experimental set-up for the electrochemical polymerization of polypyrrole films
Fig.2.1 shows a single compartmentelectrolytic cell used for the polymerization of pyrrole.
Fig.2.2 Schematic diagram of two compartment cell used fort.he polymerization reaction of pyrrole
2.6.Characterization of polypyrroles
2.6.1. UV-visible spectroscopy
2.6.2. Infrared spectroscopy
2.6.3. Scanning electron microscopy (SEM)
2.6.4. Cyclic voltammetry studies
2.6.5. TG and DTA studies
2.6.6. Ultrasonic studies
2.6.7. X-ray analysis
References
3. SYNTHESIS OF CERTAIN CONDUCTING POLYPYRROLES AND STUDY OF THEIR DC CONDUCTIVITY
3.1.Introduction
Table 3.1. Common dopants for polymers.
3.2.Experimmental set-up for conductivity measurements
3.2.1. Four point probe method
Fig.3.1. Experimental set-up for four proberesistivity measurement.
3.2.2. Two probe method
3.3.Conductivity cell
Fig.3.2.Cross sectional view of the conductivity cell.
3.4.Keithly electrometer
3.5.Work Included in this chapter
Fig.3.3. Circuit diagram of two probe set-up.
Section A
3.6.Electrochemical synthesis of conducting polypyrrole films using ammonium molybdate and traces of sulphuric acid as electrolyte and study of their DC conductivity
3.6.1. Introduction
3.6.2. Experiemental details
3.6.3. Measurement of electrical conductivity
3.6.4. Results and discussion
Table 3.3 Effect of NaOH aqueous solution treatment on conductivity
Table 3.4Effect of temperature on the film conductivity for variousfilm thickness at a current of 3 mA
Table 3.5Change of conductivity as a function of current density
Fig.3.4 Scanning electron micrographs of PPy (MoO4) 2- films prepared at various currentn densities.
3.6.5. Effect of the treatment of PPy (MoO) 2 films with aqueous sodium hydroxide solution on their electrical conductivity
Table 3.7Effect of current density on conductivity
3.6.6. Effect of alternate treatment with base and acid on conductivity
Fig.3.5.Effect of alternate treatment wit5-base andacid on conductivity of PPy (MoO4) 2-)
Section B
3.7.Electrochemical synthesis of polypyrrole films using molybdic acid as an electrolyte and investigation of their DC conductivity
3.7.1. Introduction
3.7.2. Experimental
3.7.3. DC conductivity measurements
3.7.4. Results and discussion Effect of the treatment of PPy (Mo0) 2
3.7.5. films with aqueous sodiumm hydroxide solution on their electrical conductivity
3.7.6. Effect of alternate treatement with base and acid on conductity.
Section C
3.8.Electrochemical synthesis of polypyrrole films using molybdic acid as an electrolyte and investigation of their DC conductivity
3.8.1. Introduction
3.8.2. Experimental
3.8.3. Results and discussion
3.8.4. Effect of the treatment of PPy (Mo04) 2 films with aqueous sodium hydroxide solution on their electrical conductivity
Table 3.8Effect of the temperature on the film conductivity
3.8.5. Effect of alternate treatment with base and acid on conductivity
Fig.3.7.Effect of alternate treatment with base and acid on the conductivity of PPy (P0 4)
Section D
3.9.Chemical polymerization of pyrrole using orthophosphoric acid and investigation of DC conductivity of polypyrrole films
3.9.1. Introdution
3.9.2. Experimental details
3.9.3. Results and discussion
Table 3.10Variation of conductivity of pressed pelletswith temperature
Section E
3.10.Preparation of characterization of a chemically prepared polypyrrole powder, soluble in acetone, an organic solvent
3.10.1. Introdution
3.10.2. Experimental details
3.10.3. DC conductivity studies
3.10.4. Results and discussion
CONCLUSION
References
4. INFRARED SPECTROSCOPY STUDIES
4.1.General Introduction
4.2.IR spectroscopy of polymers
4.3. Interpretation of spectra
4.3.1. Hetero aromatic compounds
4.3.2. C-H stretching vibrations
4.3.3. N-H stretching vibrations
4.3.4. Ring stretching vibrations
4.3.5. C-H out-of-plane bending
4.4.Work included in this chapter
4.5.Experimental details
4.6.Results and discussion Infrared spectra of PPy (Mo0) 2
4.6.1.films prepared electrochemically using aqueous solution of ammonium molybdate and trace at H SO4 as the electrolyte
Fig.4.1. IR spectrum of PPy (MoO4) 2 - prepared using aqueous solution of amonium molybdate and H2SO4 as electrolyte.
Table 4.1 Assignment of IR spectra
Fig.4.2. IR spectra of PPy (MoO4) 2- film prepared electrochemically at 5 c
Table 4.2 Assignment of IR spectra
4.6.2. Infrared spectra of PPy (Mo0) 2 films prepared electrochemically using aqueous solution of molybdic as the electrolyte
Fig.4.3. IR spectra of PPy (MoO4) 2- sample prepared using aqueous solution of molybdate acid as the electrolyte.
Table 4.3Assignment of IR spectra
4.6.3. Infrared spectra of PPy (PO4) films prepared electrochemically using aqueous solution of orthophosphoric acid as the electrolyte
4.6.4. FTIR spectra of PPy (PO) films prepared chemically using orthophosphoric acid in acetonitrile as the oxident acid in acetonitrile as the oxident
Fig.4.4. IR spectra of PPy (PO4) 3- film prepared at room temperature.
Table 4.4 Assignment of IR spectra
Fig.4.5. FTIR spectra of PPy (P0) film prepared chemically using H3PO4 in acetonitrile as oxident.
Table 4.5Assignment of FTIR spectra
4.6.5. FTIR spectra of PPy (PO) powder prepared chemically using orthophosphoric acid in acetone as the oxident
Fig.4.6. FTIR spectra of PPy (PO4) powder, using orthophosphoric acid in acetone as oxident.
Table 4.6 Assignment of FTIR spectra
CONCLUSION
References
5. ULTRAVIOLET-VISIBLE SPECTROSCOPY STUDIES
5.1.Introduction
5.2.Experimental
5.3.Results and discussion
Fig.5.1.UV-visible spectrum of PPy (MoO4) 2- prepared by electrochemical method.
Fig.5.2 UV-visible spectrum of PPy (MoO4) film prepared by electrochemical method using aqueous solution of molybdic acid.
Fig.5.3.UV-visible spectrum of PPy (PO4) 3- prepared by electrochemical method using aqueous solution of orthophosphoric acid as the electrolyte.
Fig.5.4.UV-visible spectrum of PPy (PO4) film synthesized chemically using H3PO4 and acetonitrile
Fig.5.5.UV-visible spectrum of PPy (PO4) powder synthesized chemically using H3PO4 and acetone.
CONCLUSION
References
6. CYCLIC VOLTAMETRIC STUDIES
6.1.Introduction
6.2.Experimental procedure
6.3.Pretreatment of platinum electrode Cyclic voltammogram studies of PPy (Ho04) 2
Fig.6.1.Schematic of the experimental arrangementfor cyclic voltammetry.
6.4.films using an aqueous solution of ammonium molybdate and H SO as the electrolyte Cyclic voltammogram studies of PPy (No0) 2
Fig.6.2.Cyclic voltammogram of thin film of PPy (Mo04) 2- for different scanning rates.
6.5.films using an aqueous solution of molybdic acid as the electrolyte Cyclic voltammogram studies of PPy (PO) 3
Fig.6.3.Cyclic voltammogram of the thick film of PPy (Mo04) 2- .
6.6.films using an aqueous solution A
Fig. 6.4.Cyclic voltammogram of thin films of PPy (Mo04) 2- for different scanning rates.
Fig.6.5.Cyclic voltammogram of PPy (PO4) 3 for different scanning rates.
CONCLUSION
References
7. ULTRASONIC STUDIES IN POLYPYRROLE SAMPLES
7.1.Introduction
7.2.Ultrasonic studies in polymers
7.3.Ultrasonic velocity measurement methods
7.3.1. Pulse-echo-overlap (PEO) method
7.3.2. Pulse-echo-overlap system
Fig.7.1. Block diagram of the equipment for echooverlap measurements with rf pulses.
Fig.7.2.Overlapped broad band echoes from thepulse-echo-overlap system.
7.4.Word done in the present study
7.5.Experimental details
7.6.Results and discussion
Table 7; l Ultrasonic velocity and attenuation of ultrasonic waves in polypyrrole solution ofdifferent concentration and teqeratures
Table 7.2 Compressibility of polypyrrole solution ofdifferent temperature and concentration
Fig.7.3. Variation of ultrasonic velocity with temperature.
Fig.7.4 variation of compressibility with temperature
Fig.7.5.Variation of ultrasonic velocity with concentration.
Fig.7.6.Variation o f compressibility with concentration.
Fig.7.7.Variation of attenuation with concentration
Table 7.3 Elastic constants for chemical prepared polypyrrole pellets
CONCLUSION
References
8. THERMOGRAVIMETRY, DIFFERENTIAL THERMAL ANALYSIS AND X-RAY STUDIES IN SOME POLYPYRROLE SAMPLES
8.1.Introduction
8.2.Experimental
Fig. 8.1.TGA of conducting polypyrrole film preparedby electrochemical method.
Fig.8.2.DTA of conducting polypyrrole film preparedby electrochemical method.
Fig.8.3.TGA of polypyrrole film prepared bychemical method.
Fig.8.4.DTA of polypyrrole film prepared bychemical method.
Fig.8.5 TGA of polypyrrole powder prepared by chemical method.
Fig.8.6.DTA of polypyrrole powder prepared by chemical method.
Fig.8.7. X-ray diffraction pattern of the polypyrrole film prepared by electrochemical methods.
Fig.8.8. x-ray diffraction pattern of the polypyrrole film prepared by chemical methods.
Fig.8.9. X-ray diffraction pattern of the polypyrrole powder prepared by chemical methods.
8.3.Results and discussion
CONCLUSION
References