Abstract
Block copolymer thin films with distinct morphologies are prepared by spin casting a nominally lamellar assay of poly(styrene-block-ethylene oxide) from a variety of solvents with and without salt doping. The 3-D morphologies of free-standing thin-film regions, which are obtained by casting directly onto holey substrates, are investigated in detail using various energy-filtering transmission electron microscopy techniques and by electron tomography. Surface characterization is achieved by atomic force microscopy. Our results demonstrate that in order to fully characterize the unique 3-D morphologies of the block copolymer thin films, a multi-method approach is required. When casting from a binary solvent, an unexpected layered honeycomb-type morphology is revealed, which likely results from an expansion of the poly(ethylene oxide) phase. A dramatic effect of selective cation coordination on the morphology of the as-cast block copolymer films is also directly observed.
Original language | English (US) |
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Pages (from-to) | 442-450 |
Number of pages | 9 |
Journal | Micron |
Volume | 44 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2013 |
Keywords
- Block copolymer morphology
- Casting solvent
- Electron tomography
- Energy-filtered TEM
- PS-b-PEO thin films
- Salt doping
ASJC Scopus subject areas
- Structural Biology
- Cell Biology