Blending Mechanism of PS- b-PEO and PS Homopolymer at the Air/Water Interface and Their Morphological Control
We report a blending mechanism of polystyrene- b-poly(ethylene oxide) (PS- b-PEO) and PS homopolymer (homoPS) at the air/water interface. Our blending mechanism is completely different from the well-known "wet-dry brush theory" for bulk blends; regardless of the size of homoPS, the domain...
Publié dans: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 34(2018), 35 vom: 04. Sept., Seite 10293-10301 |
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Auteur principal: | |
Autres auteurs: | , , |
Format: | Article en ligne |
Langue: | English |
Publié: |
2018
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Accès à la collection: | Langmuir : the ACS journal of surfaces and colloids |
Sujets: | Journal Article Research Support, Non-U.S. Gov't |
Résumé: | We report a blending mechanism of polystyrene- b-poly(ethylene oxide) (PS- b-PEO) and PS homopolymer (homoPS) at the air/water interface. Our blending mechanism is completely different from the well-known "wet-dry brush theory" for bulk blends; regardless of the size of homoPS, the domain size increased and the morphology changed without macrophase separation, whereas the homoPS of small molecular weight (MW) leads to a transition after blending into the block copolymer domains, and the large MW homoPS is phase-separated in bulk. The difference in blending mechanism at the interface is attributed to adsorption kinetics at a water/spreading solvent interface. Upon spreading, PS- b-PEO is rapidly adsorbed to the water/spreading solvent interface and forms domain first, and then homoPS accumulates on them as the solvent completely evaporates. On the basis of our proposed mechanism, we demonstrate that rapid PS- b-PEO adsorption is crucial to determine the final morphology of the blends. We additionally found that spreading preformed self-assemblies of the blends slowed down the adsorption, causing them to behave similar to bulk blends, following the "wet-dry brush theory". This new mechanism provides useful information for various block copolymer-homopolymer blending systems with large fluid/fluid interfaces such as emulsions and foams |
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Description: | Date Completed 31.10.2018 Date Revised 31.10.2018 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
ISSN: | 1520-5827 |
DOI: | 10.1021/acs.langmuir.8b02192 |