Softening of PMMA brushes upon collapse/swelling transition. A combined neutron reflectivity and nanomechanical cantilever sensor study

Sebastian Lenz, Adrian Rühm, Janos Major, Rüdiger Berger, Jochen S. Gutmann

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

In this work, we establish a direct correlation between chain mechanics and structural properties of polymer brushes upon swelling. We present experimental results on poly(methyl methacrylate) (PMMA) brushes prepared via surface initiated atomic transfer radical polymerization. Neutron reflectivity studies gave insight into the brush thickness and volume fraction profiles of the brush, gradually swollen with solvent mixtures. Comparison of our experiments with scaling theory yielded specific polymer - solvent interaction parameters and gave insight into the desorption and adsorption behavior of bad and good solvents, respectively. Insight into the brush's chain mechanics was obtained from surface stress investigations using the nanomechanical cantilever sensor bending technique. It was shown that polymer brush swelling leads to a decrease in surface stress due to chain disentanglements and the related softening of the polymer brush under θ-solvent conditions.

Original languageEnglish
Pages (from-to)360-367
Number of pages8
JournalMacromolecules
Volume44
Issue number2
DOIs
Publication statusPublished - Jan 25 2011

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ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

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