In Situ Photocontrol of Block Copolymer Morphology During Dip-Coating of Thin Films

Jaana Vapaavuori, Josue Grosrenaud, Christian Pellerin*, C. Geraldine Bazuin

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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 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. combined

Original languageEnglish
Pages (from-to)1158-1162
Number of pages5
JournalACS Macro Letters
Volume4
Issue number10
DOIs
Publication statusPublished - Oct 2015
MoE publication typeA1 Journal article-refereed

Keywords

  • DIBLOCK COPOLYMERS
  • FUNCTIONAL MATERIALS
  • WIDE-RANGE
  • AZOBENZENE
  • EVOLUTION
  • SUPRAMOLECULES
  • MOTIONS
  • PHOTOALIGNMENT
  • COMPLEXES
  • ALIGNMENT

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