Electrochemically Induced Charge and Mass Transport in Polypyrrole/ Poly(styrene Sulfonate) Molecular Composites
Abstract
Polypyrrole/poly(styrene sulfonate) (PP/PSS) molecular composites have been synthesized by the electrochemical polymerization of pyrrole in the presence of sodium poly(styrene sulfonate) (PSS-Na+). Their synthesis and charge transport properties have been investigated by a combination of electrochemical and gravimetric techniques using the Electrochemical Quartz Crystal Microbalance (EQCM). Electropolymerization in water at 0.8 V vs. Ag/AgC1 yields a partially hydrated polymer complex with sulfonate dopant anions from the PSS. Mass transport is found to be cation specific, as expected for a composite system, with the polyelectrolyte chains physically entrapped within the polymer membrane. Frequency responses of the EQCM during electrochemical switching are found to increase with increasing electrolyte cation mass as Li+is equivalent to Na+ < Cs+ < Et4N+ < Bu4N+. Chronogravimetric and chronocoulometric analyses of PP/PSS-Na+ yield apparent diffusion constants, Dapp, between 10 to the -9th power and 10 to the -11th power sq cm s for mobile hydrated Na+ species. Though the determination of theses values are complicated by the exact determination of the concentration of electroactive sites (C sub O), it is evident that reductive transport processes are faster than oxidative transport processes during switching.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 12, 1991
- Accession Number
- ADA234599
Entities
People
- Charles K. Baker
- John R. Reynolds
- Yong-jian Qiu
Organizations
- University of Texas at Arlington