Conducting polymers 2 justin

about conductivity of ploymers

1. CONDUCTING P O LYMERS JUSTIN K GEORGE ME CHEMICAL ENGINEERING 15MCH003 GUIDE – Dr. KANHAIYA JETHANI DEPARTMENT OF CHEMICAL ENGINEERING AISSMS COE PUNE -01

2. Contents Types of Conducting Polymers Intrinsically Conducting polymers Extrinsically conducting polymers Plot of conductivity Vs doping Conductivity Vs Temperature Various Applications Advantages And Disadvantages Current Visibility Future Aspects Conclusion Reference Questions

3. Types of Conducting Polymers

4. Intrinsically Conducting polymers These polymers have extensive conjugation in the backbone which is responsible for conductance. Conducting Polymers Having Conjugation Such polymers contain conjugated pie-electrons in the backbone which increases their conductivity to a large extent.

5. Doped Conducting Polymers The second condition is that the plastic has to be disturbed - either by removing electrons from ( oxidation ), or inserting them into ( reduction ), the material.The process is known as DOPING. There are two types of doping: 1-oxidation with Lewis Acid ( called p- doping). 2-Reduction with Lewis Base ( called n -doping).

6. 1-oxidation with Lewis Acid ( or p- doping)

7. 2 - Reduction with Lewis Base ( called n -doping)

8. Extrinsically conducting polymers The conductivity of these polymers is due to the addition of external ingredients.  When carbon black or some metal oxides or metallic fibers are added, the polymer becomes conductive. The minimum concentration of the element required for the conductivity is called percolation threshold. 

9. Plot of conductivity vs doping Conductivity increases up to a certain doping level 200 100 0.0 0.1 0.2 Doping level (dopant/CH unit) Conductivity (S/cm)

10. Conductivity Vs Temperature

11. Various Applications Conducting polymers have many uses.  Anti- static substances for photographic film Corrosion Inhibitors Compact Capacitors Anti Static Coating Electromagnetic shielding for computers " Smart Windows" A second generation of conducting polymers have been developed these have industrial uses like : Transistors Light Emitting Diodes ( LEDs ) Lasers used in flat televisions Solar cells   Displays in mobile telephones and mini- format television screens

12. Advantages And Disadvantages Advantages Used because of either their light weight, biological compatibility Increase speed and reduce power consumption We can make flexible transparent displays

13. Disadvantages Manufacturing costs is very high Material cost of conductive polymer is high Material of conductive polymer may become toxic after use Poor solubility in solvents and required suitable dispersion medium Conducting polymer have inability to directly melt process If we make IC by conductive polymer than the resulting IC are more sensitive and can be easily damaged by static discharge at a very low voltage

14. Current Visibility Organic Light Emitting Diodes (OLED) And Organic Polymer Solar Cell The Organic Electronics Association is an international platform to promote applications of organic semiconductors Conductive polymer products with embedded and improved electromagnetic interference (EMI) and electrostatic discharge (ESD) protection have led to both prototypes and products. Typical conductive polymers must be “doped” to produce high conductivity.

15. Future Aspects If we can produce conductive polymer at very low cost then we can reduce electrical energy wastage during energy transportation. The increased conductivity of modern conductive polymers means enough power can be put through the device at low voltage to generate practical amount of light. To make programmable floors for robotics and AGV’s (Auto Guided Vehicles) Due to the biocompatibility of some conducting polymers they may be used to transport small electrical signals through the body, i.e. act as artificial nerves.

16. Conclusion Conductive polymer or more precisely intrinsically conducting polymer(ICPs) are polymer that conduct electricity Conducting polymers are unique as possible substitute for metallic conductor and semiconductor. If we can produce conductive polymer at very low cost it will make a tremendous changes in the electric field. It is able to use in electrical ,electronics and in medical fields.

17. Reference Skotheim T.A., ed. Handbook of Conducting Polymers,Vol-1 & 2, Marcell Dekker, New York (1986) Chen C.Ku and Raimond Liepins , Electrical Properties of Polymers, Hanser Publishers, New York Bakhshi A.K, Tailoring electrically conducting polymers: An overview,, Indian Journal of Chemistry 31A (1992),291 Bakhshi A.K, Investigation of Electronic Conduction in Proteins and DNA, Progress in Biophysical Molecular Biology 61(1994),187 Ferraro J.R and J.M.Williams , Introduction to Synthetic Electrical Conductors,Academic Press , New York (1987) 6. Bredas J.L and G.B.Street , Polarons and Bipolarons , Accounts of Chemical Research 18(1985),309-315

18. Questions ?

19. THANK YOU