Electrical_Properties_of_Conducting_Polymers.pptx

Electrical_Properties_of_Conducting_Polymers

1. Electrical Properties of Conducting Polymers Name: [Your Name] Course: [Course Title] Instructor: [Instructor’s Name] Date: [Date]

2. Introduction Conducting polymers are synthetic metallic polymers with electrical conductivity. They are formed from repeating monomer units with delocalized π-electrons. Properties depend on crystallinity, molecular order, and defects. Applications: electronics, energy devices, and sensors.

3. Structure and Delocalization Alternating single and double bonds in carbon chain (conjugation). Delocalized π-electrons enable electron mobility. Conductivity can be tuned using doping or light/electric fields. Example: Polyacetylene – simplest conjugated polymer.

4. Electrical Conductivity Mechanism Similar to metals: delocalized charge carriers and partially filled bands. Organic polymers have localized valence electrons unless conjugated. Conjugated double bonds create delocalized orbitals (π-bonds) for conduction. Example: trans-polyacetylene structure.

5. Charge Carriers in Conducting Polymers Solitons: neutral quasiparticles that move through the chain. Polarons: charged carriers (±e) coupled with unpaired electrons. Bipolarons: pairs of polarons with charge ±2e. Doping creates or enhances these charge carriers.

6. Band Gap Theory Undoped polymers act as semiconductors (band gap 1–3 eV). Doping decreases the band gap → higher conductivity. Polarons and bipolarons introduce new energy levels. Heavily doped polymers form metallic-like bands.

7. Classification of Conducting Polymers 1. Intrinsically Conducting Polymers: Have delocalized π-electrons (e.g., PANI, PTh). 2. Extrinsically Conducting Polymers: Conductivity from added fillers (e.g., carbon black composites).

8. Conjugated Conducting Polymers Backbone of alternating single/double bonds. Examples: PANI, PPy, PTh, PA. PEDOT: high conductivity & stability for flexible electronics. PANI: reversible redox behavior → sensors, supercapacitors.

9. Doped Conducting Polymers P-doping: oxidation (e.g., iodine). N-doping: reduction (e.g., Na, FeCl₃). Enhances conductivity by introducing charge carriers. Used in energy and display applications.

10. Factors Affecting Electrical Conductivity Polymer structure and morphology. Doping level and type. Temperature and environmental conditions. Processing conditions and additives (graphene, CNTs).

11. Applications (1/2) Flexible Electronics: Smart textiles, wearable sensors. Energy Storage: Supercapacitors and lightweight batteries. Organic Solar Cells: Cost-effective and flexible photovoltaic devices.

12. Applications (2/2) Sensors: Chemical and biosensors for diagnostics. OLEDs: Improved charge transport in displays. Antistatic Coatings: Prevent static buildup and EMI shielding. Transistors: Used in flexible organic circuits.

13. Conclusion Conducting polymers bridge insulators and metals. Key features: delocalized π-electrons and conjugated systems. Tunable conductivity via doping and structural modification. Essential for future electronics and renewable energy.

14. Future Prospects Improve long-term stability and scalability. Develop eco-friendly synthesis methods. Integration into flexible and wearable smart devices. Explore hybrid composites for enhanced performance.

15. References Include latest research papers and review articles on conducting polymers (APA style).