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Research Zernike (ZIAM) News Seminars

Jaana Vapaavuori: Taming Macromolecules by Light - Supramolecular Photoresponsive Materials at Three Different Length Scales

When:We 14-02-2018 15:45 - 16:45
Where:5114.0043

When noncovalently bound to macromolecules, photoresponsive azobenzene derivatives can be harnessed for controlling the properties of materials at length scales spanning at least three orders of magnitude. In this presentation, I will discuss my recent work seeking fundamental understanding of how the nanometer-scale photoinduced changes in azobenzene geometry can be translated into different applications involving polymers. First, starting from the length scale of 10-100 nm, the morphology of self-assembled diblock copolymers can be switched by supramolecularly attaching azobenzene molecules selectively to one of the blocks. Second, by using a novel IR method, the molecular-level origins of the photoinduced surface patterning, in which azobenzene motion is converted into micron-scale material motion, are elucidated. Third, stimuli-induced (light and humidity) changes visible at the macroscopic scales are discussed, by introducing supramolecular polymer-azobenzene humidity memories and light-switchable polymer wrinkles at the scale of approximately 10-100 μm. This presentation highlights that the key to achieving high-tech applications is to first understand the delicate balance of supramolecular interactions in soft condensed materials, and then develop methods for controlling them.