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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 25: Interfaces and Thin Films II

CPP 25.4: Vortrag

Dienstag, 13. März 2018, 10:30–10:45, PC 203

Near surface dynamics of PEG and PNIPAM based polymer brushes — •Judith Witte¹, Tetyana Kyrey^1,2, Regine von Klitzing³, Olaf Holderer², and Stefan Wellert¹ — ¹TU Berlin, Institute for Chemistry, Berlin, Germany — ²Heinz Maier Leibniz Zentrum, JCNS, Garching, Germany — ³TU Darmstadt, Institute for Condensed Matter Physics, Darmstadt, Germany

The physical properties of stimuli-responsive polymer brushes still receive vast interest in basic research. Polymer brushes undergoing a temperature induced phase transition are of major interest for technical applications such as (bio)functional coatings. Polymer brushes are polymers end-tethered to a solid surface. A variation of the chemical composition, brush height or grafting density allows for a wide range of different polymer coatings with distinct properties. Among them, thermoresponsive polymer brushes based on P(MEO₂MA-co-OEGMA) are, due to their biocompatibility, promising candidates for smart biocoatings. PNIPAM based polymer brushes serve as a prominent model system for thermoresponsive polymer coatings. Here we focus on recent grazing incidence neutron spin echo spectroscopy experiments probing the dynamics inside these polymer brush layers on the nanometer length and nanosecond time scale. At two neutron penetration depths we explored the segmental dynamics well below the LCST. The data suggest an influence of the nonuniform blob size on the relaxation time inside the brushes which is discussed in the talk.