The Link Between Self-Assembly and Molecular Conformation of Amphiphilic Block Copolymers Monolayers at the Air/Water Interface : The Spreading Parameter
Two amphiphilic block copolymers, namely polystyrene-b-poly(methyl-methacrylate) (PS-b-PMMA), at the air/water interface were studied combining the in situ structural characterization, by means of X-ray reflectivity (XRR) and grazing incidence small-angle X-ray scattering (GISAXS), and the ex situ m...
Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 31(2015), 32 vom: 18. Aug., Seite 8856-64 |
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Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
2015
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Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
Schlagworte: | Journal Article |
Zusammenfassung: | Two amphiphilic block copolymers, namely polystyrene-b-poly(methyl-methacrylate) (PS-b-PMMA), at the air/water interface were studied combining the in situ structural characterization, by means of X-ray reflectivity (XRR) and grazing incidence small-angle X-ray scattering (GISAXS), and the ex situ morphological one, by atomic force microscopy (AFM). We observed that the conformation of the hydrophilic block spread on the water surface is dramatically influenced by the morphology of the monolayer. Our results showed that the hydrophilic PMMA block adopts an expanded conformation when thermodynamically stable nanodots are formed, whereas a coiled conformation is observed when the block copolymer formed kinetically frozen nanostrands. This effect is interpreted in terms of the spreading parameter, which changes with the relative length ratio between the two blocks. Finally, we proved that, even for block copolymer monolayer with fixed block length ratio, it is possible to change the morphology, and in turn the conformation of the hydrophilic block, by changing the spreading parameter value |
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Beschreibung: | Date Completed 26.10.2015 Date Revised 18.08.2015 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
ISSN: | 1520-5827 |
DOI: | 10.1021/acs.langmuir.5b02054 |