Polyacetylene and polyaniline: Synthesis, doping, and characterization

Miscellaneous · Fri Jan 01 00:00:00 EST 1993

OSTI ID:6987647

Swanson, D B

Selected properties of two conducting polymers, viz., polyacetylene, (CH)[sub x], and polyaniline are studied. Polyacetylene. Reported values of conductivity for iodine-doped, non-aligned films of four types of polyacetylene, viz., S-(CH)[sub x], vary between 500 S/cm and 10,000 S/cm. the present study was carried out in order to understand why these different types of the same polymer have such different conductivities. the chief results and conclusions were: (i) through careful synthesis, purification and characterization of S-, N-, and [upsilon]-(CH)[sub x], it was concluded that while conductivity values of samples from a given synthesis are similar, they vary by up to [+-] 80% between different syntheses of the same type of (CH)[sub x]; (ii) films of N-(CH)[sub x] and [upsilon]-(CH)[sub x] both contain large and approximately equal amounts of catalyst impurities, as compared to films of S-(CH)[sub x], which contain essentially no impurity. It is concluded that impurities have no significant effect on the conductivity of these iodine-doped films. In order to ascertain optimum doping conditions for (CH)[sub x] films, an in-situ Impedance Profiling technique was developed to continually monitor the conductivity of the (CH)[sub x] during the actual redox or protonic acid doping process in aqueous and non-aqueous media. Polyaniline. A reported hysteresis in the conductivity of protonic acid doped polyaniline was studied using Impedance profiling. The chief results and conclusions were: (i) hysteresis was observed in pristine, NMP-cast polyaniline films only in the first doping/undoping cycle, but was absent in additional doping/undoping cycle.s It was concluded that the hysteresis was due to significant amounts of crystallinity in the pristine films, which was eliminated during the first doping/undoping cycle; (ii) the reported hysteresis in conductivity of polyaniline powder is amorphous, no hysteresis was observed at equilibrium, even in the first doping cycle.

• Research Organization: Pennsylvania Univ., Philadelphia, PA (United States)
• OSTI ID: 6987647
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANILINE
CRYSTAL DOPING
ELECTRIC CONDUCTIVITY
SYNTHESIS
POLYACETYLENES
ELECTRIC CONDUCTORS
ELECTRIC IMPEDANCE
HYSTERESIS
ORGANIC POLYMERS
AMINES
AROMATICS
ELECTRICAL PROPERTIES
HYDROCARBONS
IMPEDANCE
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
POLYENES
POLYMERS
360606* - Other Materials- Physical Properties- (1992-)
360601 - Other Materials- Preparation & Manufacture