Abstract
This paper elucidates the extent of changes in surface wettability as influenced by the surface topography on a conducting polymer, polypyrrole. As-deposited, anion-doped polypyrrole is subjected to a series of incremental redox potentials ranging from -0.6 V to +1.5 V (vs. Ag/AgCl), and its surface properties are examined via SEM, AFM, and contact angle measurements. A causal relationship is found to exist between the oxidation states of polypyrrole and its surface topography. At redox potential lower than +0.6 V, the polymer is completely hydrophilic (contact angle <90deg) as ascribed partially to its smooth surface. It becomes less hydrophilic in the range of +0.6-+1.0 V and turns totally hydrophobic beyond +1.0 V. Such a change in surface wettability is attributed in part to the increased surface roughness, as measured by AFM. As redox potentials increase from -0.6 V to +1.5 V, the corresponding average surface roughness rises from 3.1 nm to 31.1 nm - a 10-fold increase. Visual inspection by SEM indicates the formation of islets on the polymer during the oxidation process. Based on our experimental results, we hypothesize that as redox potential increases, changes of surface topography decrease the surface wettability of polypyrrole.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
