Effect of superhydrophobicity on the barrier properties of polymethylene films
Superhydrophobic polymethylene (PM) films provide remarkable protection against the transport of aqueous redox probes as a result of entrapped air at the water/polymer interface. The wetting properties and the topography for a set of superhydrophobic (SH) and nonsuperhydrophobic (NSH) PM films were...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 26(2010), 17 vom: 07. Sept., Seite 14039-46 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2010
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. Membranes, Artificial Polymers Water 059QF0KO0R Gold 7440-57-5 Methane OP0UW79H66 |
| Zusammenfassung: | Superhydrophobic polymethylene (PM) films provide remarkable protection against the transport of aqueous redox probes as a result of entrapped air at the water/polymer interface. The wetting properties and the topography for a set of superhydrophobic (SH) and nonsuperhydrophobic (NSH) PM films were established to compare their interfacial behavior using electrochemical impedance spectroscopy (EIS). EIS results show that SH PM films exhibit resistances against ion transfer that are approximately 3 orders of magnitude higher than those of NSH PM films. Rationalization of these results in the context of the Helmholtz theory reveals that the imaginary impedance or inverse capacitance of SH PM films exhibits positive deviations from that predicted by Helmholtz theory for smooth PM films. Here, we model the capacitance behavior of a SH film as a PM/air composite that acts as a circuit of capacitors. The resulting mathematical model of this analysis enables correlation of the effective dielectric properties of the film (d(effective), epsilon(effective)) to measurable properties such as thickness (d(film)) and the dielectric constant (epsilon(PM)) of the PM film. Finally, a sensitivity analysis shows that the limited contact area between the aqueous solution and PM in SH films is the primary reason for the enhancement in the barrier properties of the film |
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| Beschreibung: | Date Completed 27.12.2010 Date Revised 21.11.2013 published: Print Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la102312w |