Abstract
We demonstrate a unique combination of simultaneous top-down and bottom-up control of the morphology of block copolymer films by application of in situ optical irradiation during dip-coating. A light-addressable and block-selective small molecule, 4-butyl-4′-hydroxyazobenzene (BHAB), is introduced into a diblock copolymer of polystyrene and poly(4-vinylpyridine) (PS-P4VP) of 28.4 wt % P4VP via supramolecular chemistry, notably by hydrogen bonding to P4VP. We show that the spherical morphology of thin films dip-coated from a THF solution at slow withdrawal rates in the dark convert to cylindrical morphology when dip-coated under illumination. This is attributed to volume expansion of the P4VP/BHAB phase due to trans-cis photoisomerization combined with a light-induced increase in BHAB uptake in the film. The demonstrated photocontrol highlights the potential of dip-coating as a scalable film preparation method that can be easily coupled with external stimuli to direct nanostructured self-assembly in the films as solvent evaporates.
Original language | English |
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Pages (from-to) | 1158-1162 |
Number of pages | 5 |
Journal | ACS Macro Letters |
Volume | 4 |
Issue number | 10 |
DOIs | |
Publication status | Published - 20 Oct 2015 |
Publication type | A1 Journal article-refereed |
ASJC Scopus subject areas
- Organic Chemistry
- Materials Chemistry
- Polymers and Plastics
- Inorganic Chemistry