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Thermodynamic properties and morphology of 2D NBR/PEG-PPG-PEG networks. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Vaillard AS, El Haitami A, Dreier LB, Fontaine P, Cousin F, Gutfreund P, Goldmann M, Backus EHG, Cantin S. Vertically Heterogeneous 2D Semi-Interpenetrating Networks Based on Cellulose Acetate and Cross-Linked Polybutadiene. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:2538-2549. [PMID: 35171621 DOI: 10.1021/acs.langmuir.1c03084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This work reports the feasibility of polybutadiene (PB) cross-linking under UV irradiation in the presence of a linear polymer, cellulose acetate (CA), to form semi-interpenetrating polymer networks at the air-water interface. The thermodynamic properties and the morphology of two-dimensional (2D) CA/PB blends are investigated after UV irradiation and for a wide range of CA volume fractions. A contraction of the mixed Langmuir films is observed independent of the composition, in agreement with that recorded for the individual PB monolayer after cross-linking. The PB network formation is demonstrated by in situ sum-frequency generation spectroscopy on the equivolumic CA/PB mixed film. From Brewster angle microscopy observations, the PB network synthesis does not induce any morphology change at the mesoscopic scale, and all of the mixed films remain homogeneous laterally. In situ neutron reflectometry is used to probe the effect of PB cross-linking on the vertical structure of CA/PB mixed films. For all studied compositions, significant thickening of the films is evidenced, consistent with their contraction ratio. This thickening is accompanied by a partial expulsion of the PB toward the film-air interface, which is attributed to the hydrophobic character of the PB. This phenomenon is stronger for films rich in PB. In particular, the structure of the PB-rich film undergoes a transition from vertically homogeneous to inhomogeneous along the depth. 2D semi-interpenetrating polymer networks can thus be synthesized at the air-water interface with a morphology that is strongly influenced by the polymer-polymer and polymer-environment interactions.
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Affiliation(s)
| | | | - Lisa B Dreier
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Philippe Fontaine
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Gif sur Yvette Cedex, France
| | - Fabrice Cousin
- Laboratoire Léon Brillouin, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | | | - Michel Goldmann
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Gif sur Yvette Cedex, France
- Institut des NanoSciences de Paris, Sorbonne Université, 75252 Paris Cedex 05, France
- Faculté des Sciences Fondamentales et Biomédicales, Université de Paris, 75006 Paris, France
| | - Ellen H G Backus
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Department of Physical Chemistry, University of Vienna, Währinger Strasse 42, A-1090 Vienna, Austria
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Ho K, Kim KS, de Beer S, Walker GC. Chemical Composition and Strain at Interfaces between Different Morphologies in Block Copolymer Thin Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12723-12731. [PMID: 34693716 DOI: 10.1021/acs.langmuir.1c02169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Transitional composition between two thin-film morphologies of the block copolymer, polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBuA), was investigated using near-field infrared spectroscopy and atomic force microscopy mechanical measurements. These techniques allowed block identification with nanoscale spatial resolution and elucidated the material's sub-surface composition. PS was found to form coronae around the PtBuA block in spherical valleys on flat areas of the film, and coronae of PtBuA surrounding the PS lamellae were observed at the edge of the polymer film, where parallel lamellae are formed. Furthermore, we found that the peak position and width varied by location, which may be a result of block composition, chain tension, or substrate interaction.
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Affiliation(s)
- Kevin Ho
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Kris S Kim
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Sissi de Beer
- Sustainable Polymer Chemistry, Department of Molecules & Materials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede 7500 AE, The Netherlands
| | - Gilbert C Walker
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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