Effects of annealing on the molecular orientation in polytetrafluoroethylene thin films

Kobayashi, Eiichi; Okudaira, Koji K.; Okajima, Toshihiro

doi:10.1002/sia.4895

Cited by 7 publications

(3 citation statements)

References 12 publications

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“…Importantly, the fact that excitations arise from two initial states separated by approximately 1 eV (i.e., 2p 1/2 and 2p 3/2 ) makes it somewhat difficult to interpret the sulfur edge since one essentially has two spectra superimposed and shifted by 1 eV . Nevertheless, the NEXAFS spectra are comparable to those obtained elsewhere for the S(2p) absorption edge of thiophene functional groups. , The characteristic multiplet peak in the spectrum obtained prior to sputtering is indicative of a highly oriented chemical species. , Conversely, the spectra obtained following argon ion sputtering reveals a broad peak, which is suggestive of highly disordered thiophene species, probably randomly orientated polymer molecules in a multitude of chemical states. , This is not unexpected since sulfur in POT is known to exist in a variety of dispersed chemical states, which would cause considerable overlap in the NEXAFS spectra. The net result of this would be a broad, convoluted peak as seen in the spectrum relating to the bulk of the polymer.…”

Section: Resultsmentioning

confidence: 64%

“…22,33 Conversely, the spectra obtained following argon ion sputtering reveals a broad peak, which is suggestive of highly disordered thiophene species, probably randomly orientated polymer molecules in a multitude of chemical states. 34,35 This is not unexpected since sulfur in POT is known to exist in a variety of dispersed chemical states, 36 which would cause considerable overlap in the NEXAFS spectra. The net result of this would be a broad, convoluted peak as seen in the spectrum relating to the bulk of the polymer.…”

Section: ■ Results and Discussionmentioning

confidence: 89%

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Evidence for a Surface Confined Ion-to-Electron Transduction Reaction in Solid-Contact Ion-Selective Electrodes Based on Poly(3-octylthiophene)

et al. 2013

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The ion-to-electron transduction reaction mechanism at the buried interface of the electrosynthesized poly(3-octylthiophene) (POT) solid-contact (SC) ion-selective electrode (ISE) polymeric membrane has been studied using synchrotron radiation-X-ray photoelectron spectroscopy (SR-XPS), near edge X-ray absorption fine structure (NEXAFS), and electrochemical impedance spectroscopy (EIS)/neutron reflectometry (NR). The tetrakis[3,5-bis(triflouromethyl)phenyl]borate (TFPB(-)) membrane dopant in the polymer ISE was transferred from the polymeric membrane to the outer surface layer of the SC on oxidation of POT but did not migrate further into the oxidized POT SC. The TFPB(-) and oxidized POT species could only be detected at the outer surface layer (≤14 Ǻ) of the SC material, even after oxidation of the electropolymerized POT SC for an hour at high anodic potential demonstrating that the ion-to-electron transduction reaction is a surface confined process. Accordingly, this study provides the first direct structural evidence of ion-to-electron transduction in the electropolymerized POT SC ISE by proving TFPB(-) transport from the polymeric ISE membrane to the oxidized POT SC at the buried interface of the SC ISE. It is inferred that the performance of the POT SC ISE is independent of the thickness of the POT SC but is instead contingent on the POT SC surface reactivity and/or electrical capacitance of the POT SC. In particular, the results suggest that the electropolymerized POT conducting polymer may spontaneously form a mixed surface/bulk oxidation state, which may explain the unusually high potential stability of the resulting ISE. It is anticipated that this new understanding of ion-to-electron transduction with electropolymerized POT SC ISEs will enable the development of new and improved devices with enhanced analytical performance attributes.

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Section: Resultsmentioning

confidence: 64%

Section: ■ Results and Discussionmentioning

confidence: 89%

Evidence for a Surface Confined Ion-to-Electron Transduction Reaction in Solid-Contact Ion-Selective Electrodes Based on Poly(3-octylthiophene)

et al. 2013

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“…Tripathi et al [14] found the columnar nanostructures were produced by annealing for the PTFE film by magnetron sputtering. Kobayashi et al [15] observed that the molecules in PTFE films were increasingly oriented normal to the substrate surface with increasing annealing temperature. In our previous report, the PTFE film density was greatly increased with increasing annealing temperature and the optimal mechanical properties could be obtained by annealing at 100 °C [16].…”

Section: Introductionmentioning

confidence: 99%

Unveiling the growth mode and structure relaxation of Polytetrafluoroethylene film by radio-frequency magnetron sputtering

et al. 2022

Mater. Res. Express

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Relying on radio-frequency (RF) magnetron sputtering, Polytetrafluoroethylene (PTFE) films with a series of thicknesses in the range from 80 to 2000 nm were prepared on silicon substrates. The surface morphology and roughness of the PTFE films were measured by atomic force microscope (AFM) technology at microscale. Results indicated that the PTFE film grew in an island pattern during sputtering, while the surface roughness of PTFE films was almost invariable throughout the sputtering process. Then the structure relaxation of PTFE film annealed at 100℃ for 15-480 mins was investigated. Annealing treatment induced columnar protrusions on the PTFE surface, which was due to the flow and rearrangement of molecules. During annealing duration, the columnar structures could continuously rearrange and decompose, and therefore lowering film thickness from 2000 to 1110 nm with increasing annealing time. Due to molecule flow and redistribution of the annealed film, the columnar structures were formed on the surface, which resulted in the higher roughness. Finally, the effects of film thickness and annealing time on the hydrophobicity were also studied.

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The effects of annealing conditions on the wear of PDA/PTFE coatings

Jiang

Choudhury

Brownell

et al. 2019

Applied Surface Science

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Effects of annealing on the molecular orientation in polytetrafluoroethylene thin films

Cited by 7 publications

References 12 publications

Evidence for a Surface Confined Ion-to-Electron Transduction Reaction in Solid-Contact Ion-Selective Electrodes Based on Poly(3-octylthiophene)

Evidence for a Surface Confined Ion-to-Electron Transduction Reaction in Solid-Contact Ion-Selective Electrodes Based on Poly(3-octylthiophene)

Unveiling the growth mode and structure relaxation of Polytetrafluoroethylene film by radio-frequency magnetron sputtering

The effects of annealing conditions on the wear of PDA/PTFE coatings

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