INTERACTIONS OF NEUTRAL ORGANICS IN AQUEOUS-SOLUTION WITH CONDUCTING POLYMER-FILMS OF POLY(N-METHYLPYRROLE) AND POLY(N-METHYLPYRROLE POLYSTYRENESULFONATE)

We have investigated the interactions between halocarbons in aqueous s olution and conducting polymer films of poly(N-methylpyrrole) (PNMP) a nd poly(N-methylpyrrole/polystyrenesulfonate) (PNMP/PSS) employing cyc lic voltammetry, UV-visible spectroelectrochemistry, and electrochemic al quartz crystal microgravimetry (EQCM). The absorption of dichlorome thane (DCM) into both films is adequately described by the Langmuir is otherm model for monolayer sorption. The partitioning of DCM from the aqueous phase into reduced PNMP is up to 2.5 times greater than the pa rtitioning into the oxidized form of the polymer. The amount of DCM ab sorbed by both redox forms of the PNMP/PSS composite film is, however, identical. These observations are discussed in terms of the changes ( or lack thereof) in chemical, physical, and morphological properties t hat accompany the redox processes of these films. Spectroscopic measur ements suggest that there is slight chemical interaction between DCM a nd reduced PNMP and PNMP/PSS, but there is much less interaction with the oxidized polymers.