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Ito K, Harada M, Yamada NL, Kudo K, Aoki H, Kanaya T. Water Distribution in Nafion Thin Films on Hydrophilic and Hydrophobic Carbon Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12830-12837. [PMID: 33085483 DOI: 10.1021/acs.langmuir.0c01917] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We performed H2O and D2O double-contrast neutron reflectivity measurements on ∼25 nm thick Nafion thin films on hydrophilic and hydrophobic carbon in water and 80% relative humidity vapor to investigate the depth profile of the water and Nafion distribution. We found a dense Nafion layer at the air or water interface regardless of the carbon hydrophilicity. On the other hand, a water-rich Nafion dense layer was observed at the carbon interface only for hydrophilic carbon. The double-contrast measurements provided quantitative information about the depth profile but simultaneously indicated that the sum of the volume occupancies of water and Nafion in the film was less than unity. We assessed the problem based on two possibilities: voids in the film or "residual water", which cannot be exchanged or is difficult to exchange with water outside.
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Affiliation(s)
- Kanae Ito
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Masashi Harada
- Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Norifumi L Yamada
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Kenji Kudo
- Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Hiroyuki Aoki
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Toshiji Kanaya
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
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Vaillard AS, El Haitami A, Dreier LB, Backus EHG, Cantin S. Confinement and Cross-Linking of 1,2-Polybutadiene in Two Dimensions at the Air-Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:862-871. [PMID: 31935102 DOI: 10.1021/acs.langmuir.9b03297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Langmuir monolayers of 1,2-polybutadiene (PB) were investigated by means of surface pressure-area isotherms, Brewster angle microscopy (BAM) observations, and sum-frequency generation (SFG) spectroscopy. A homogeneous and stable monolayer is formed 1.5 h after PB spreading provided that both light and oxygen are present. This was attributed to a slight oxidation of the PB at the air-water interface. The cross-linking of PB under UV photoirradiation was then studied. SFG spectroscopy demonstrates the in situ formation of a two-dimensional network. From surface pressure-area characterizations and BAM experiments, the cross-linked PB monolayer appears significantly denser and more rigid than the non-irradiated monolayer. Atomic force microscopy images reveal an increase by a factor of three in the root-mean-square roughness of the irradiated monolayers compared with the non-irradiated ones.
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Affiliation(s)
- Anne-Sophie Vaillard
- Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI, EA 2528) , Institut des Matériaux, CY Cergy Paris Université , 5 mail Gay-Lussac Neuville/Oise , Cergy-Pontoise Cedex 95031 , France
| | - Alae El Haitami
- Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI, EA 2528) , Institut des Matériaux, CY Cergy Paris Université , 5 mail Gay-Lussac Neuville/Oise , Cergy-Pontoise Cedex 95031 , France
| | - Lisa B Dreier
- Max Planck Institute for Polymer Research , Ackermannweg 10 , Mainz 55128 , Germany
| | - Ellen H G Backus
- Max Planck Institute for Polymer Research , Ackermannweg 10 , Mainz 55128 , Germany
- Department of Physical Chemistry , Währinger Strasse 42 , Vienna A-1090 , Austria
| | - Sophie Cantin
- Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI, EA 2528) , Institut des Matériaux, CY Cergy Paris Université , 5 mail Gay-Lussac Neuville/Oise , Cergy-Pontoise Cedex 95031 , France
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Ning N, Mi T, Chu G, Zhang LQ, Liu L, Tian M, Yu HT, Lu YL. A quantitative approach to study the interface of carbon nanotubes/elastomer nanocomposites. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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