Biomolecules and nanostructures
The Optical Sciences group studies the interaction of light and matter at the nanoscale.
We do this by exploring ways to shape light and its environment. It's what we call
active and passive control. Our current focus is on the interaction of light with
biomolecules and nanostructures. We are part of Twente
University's Department of Science and Technology and member of the
Effect of solvent on nanoscale polymer heterogeneity and mobility probed by single molecule lifetime fluctuations(full pdf)
Vallee RAL, Tomczak N, Kuipers L, Vancso GJ, van Hulst NF
CHEMICAL PHYSICS LETTERS
vol. 384 issues1-3: p5-p8 jan 19 2004
In this Letter, we address nanoscale heterogeneity in polymer mobility. Single molecule fluorescence lifetime fluctuations are exploited as a probe for local segmental dynamics in polymer films. Wide distributions in polymer mobility are observed, which depend on film fabrication, treatment and amount of solvent contained. Upon solvent evaporation mobile regions disappear, while more immobile regions settle, effectively increasing the glass transition temperature. Besides insight in polymer nanoscale dynamics and heterogeneity, our results bear specific relevance to photodynamic studies on single chromophores, where routinely polymer matrices are used for immobilization. (C) 2003 Elsevier B.V. All rights reserved.