Conducting Polymers

Question 1

conducting polymers

Answer 1

group of organo electronic polymers conducting electricity

Question 2

doping

Answer 2

process of transforming a polymer to its conductive form through a chem oxdn or redn reaction

Question 3

classification of conducting polymers

Answer 3

intrinsic

extrinsic

Question 4

classification of intrinsic conducting polymers

Answer 4

conjugated polymers

doped polymers

Question 5

classification of extrinsic conducting polymers

Answer 5

element filled polymers

blended polymers

Question 6

2 methods of doping

Answer 6

positive doping

negative doping

Question 7

positive doping

Answer 7

oxdn process brought about by lewis acids

Question 8

negative doping

Answer 8

redn process brought about by lewis bases

Question 9

how are blended conducting polymers formed

Answer 9

obtained by blending a conventional polymer with a conducting polymer

Question 10

properties of conducting polymers

Answer 10

1) good conductivity
2) high ability for charge storage
3) ability to exchange ions
4) absorbs visible light to give coloured products
5) transparent to X rays
6) products obtained are economic, recyclable, having high stability and excellent props
7) poor mech strength, chem resistance and improcessability

Question 11

polyaniline

Answer 11

stable and highly tunable conducting polymer

Question 12

how is polyaniline prepared

Answer 12

by both chem and electrochem oxidative polymerization of aniline

Question 13

4 main oxdn states of polyaniline

Answer 13

1) leucomeraldine base
2) emeraldine base
3) emeraldine salts
4) pernigraniline

Question 14

properties of polyaniline

Answer 14

1) light weight, highly flexible
2) semicond at ordinary condn, can be conv to wide range of conductors using diff doping
3) high chem R
4) processed in various shapes
5) inexpensive, having 3 distinct oxdn states, has an acid or base doping response

Question 15

applications of polyaniline

Answer 15

1) electrically conducting yarns, electromag shielding, flexible electrodes
2) chem vapour sensors and biosensors
3) actuators, super capacitors, electrochromics
4) printed circuit boards
5) hole injection layers in OLED
6) constrn fielnd for corrn resistant treatment
7) to make light weight rechargeable batteries

Question 16

polypyrrole

Answer 16

hetero atomic stable cond polymer formed from a no. of connected pyrrole ring structures

Question 17

properties of polypyrrole

Answer 17

1) films are yellow but darken due to oxdn but doped are blue or black
2) undoped and doped films are insoluble in solvents but swellable
3) insulatr but its oxidative derivatives are good electrical conductors

Question 18

applications of polypyrrole

Answer 18

1) biosensors, gas sensors
2) excellent thermal stability
3) potential vehicle for drug delivery
4) medical industry
5) protect corrn of metals
6) catalyst support for fuel cells

Question 19

OLED

Answer 19

organic light emitting diodes

Question 20

advantages of oled

Answer 20

1) good quality light colour
2) dimmable
3) cold lighting sources
4) greater efficiency levels
5) small, light, thin, flexible

Question 21

parts of oled structure

Answer 21

1) substrate
2) anode
3) hole transport layer
4) electron transport layer
5) metallic cathode

Question 22

advantages of oled layer

Answer 22

1) the plastic, organic layers are thinner, lighter, more flexible
2) brighter
3) do not require back lighting
4) easier to produce
5) produce their own light

Question 23

disadvantages of oled

Answer 23

1) limited lifetime

2) organic materials can be damaged

Question 24

applications of oled

Answer 24

1) oled tv
2) mobile phones with oled screens
3) smart watch
4) roll top laptop