Polyacetylene and polyaniline: Synthesis, doping, and characterization

Thesis/Dissertation · Fri Jan 01 04:00:00 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
• Country of Publication: United States
• Language: English

Related Subjects

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