ALAN G. MACDIARMID

DESCRIPTION OF RESEARCH INTERESTS:

My research is directed to the study of conducting polymers, more commonly known as "synthetic metals". They are organic polymers that possess the electrical, electronic, magnetic and optical properties of a metal while retaining the mechanical properties, processibility etc., commonly associated with a conventional polymer. Their properties are intrinsic to a "doped" form of the polymer. The concept of doping is the unique, central characteristic which distinguishes conducting polymers from all other types of polymers. During the doping process, an organic polymer, either an insulator or semiconductor having a small conductivity, typically in the range of 10P10 to 10P5 S/cm, is converted to a polymer which is in the "metallic" regime (~1 to ~104 S/cm). The controlled addition of known, usually small (<10%) and non-stoichiometric quantities of chemical species results in dramatic changes in the electronic, electrical, magnetic, optical and structural properties of the polymer. Doping is reversible to produce the original polymer with little or no degradation of the polymer backbone. Both doping and undoping processes, involving dopant counter ions which stabilize the doped state, may be carried out chemically or electrochemically.

Since the discovery of conducting polymers at Penn in the mid-seventies, the field has expanded extremely rapidly world-wide. This has resulted both from the interdisciplinary nature of the field -- chemistry, electrochemistry, physics, electrical/electronic engineering -- and from the rapidly expanding technological interest in the field.

My work is currently concerned primarily with the conducting polymer, polyaniline, and its derivatives and their technological applications. It involves bench and vacuum line syntheses, chemical and electrochemical doping and structural/morphological studies. It is directed basically towards ascertaining factors which contribute to high conductivity in organic polymers in general in order to determine the ultimate conductivity attainable by an organic polymer.