Warning: We observe an increase of emails from fake travel portals like . "travelhosting.co.uk". We never send links to such portals so be vigilant!

May 22 – 25, 2023
Europe/Berlin timezone

Polymer Brushes: topology variation and influence on nanoscale hydration

May 22, 2023, 2:30 PM
Schloss Fürstenried (Munich)

Schloss Fürstenried


Forst-Kasten-Allee 103 81475 München Germany
Talk Biomimetics and alive systems Biomimetics and alive systems


Apostolos Vagias (FRM2 / TUM)


By utilizing time-of-flight neutron reflectometry (ToF-NR) under different relative humidity, we demonstrate that polymer brushes constituted by hydrophilic cyclic macromolecules exhibit more compact conformation with lower roughness compared to linear brush analogues, due to the absence of dangling chain ends extending at the interface. [1] In addition, due to increased interchain steric repulsions, cyclic brushes feature larger swelling ratio and increased solvent uptake with respect to their linear counterparts presenting the same composition and comparable molar mass. Moreover, the two topologies exhibit differences in ageing, upon repetitive cycling/drying trials.
To correlate the equilibrium swelling ratios as a function of relative humidity for different topologies a new form of the Flory-like expression for equilibrium thicknesses is proposed. The relative humidity represents the chemical potential balance between brush and surrounding environment. The Flory-like expression, which has been utilized so far for thin polymer films, breaks down for the cyclic brush. Additional topological contributions need to be taken into account in this expression, in order to rationalize differences reflected in swelling ratios and solvent content between the linear and cyclic polymer brush topologies.

[1] Vagias, A., Nelson, A., Wang, P., Reitenbach, J., Geiger, C., Kreuzer, L. P., Saerbeck, T., Cubitt, R., Benetti, E. M., Müller-Buschbaum, P., The Topology of Polymer Brushes Determines Their Nanoscale Hydration. Macromol. Rapid Commun. 2023, 2300035

Primary authors

Apostolos Vagias (FRM2 / TUM) Dr Andrew Nelson (ANSTO) Peixi Wang (Workgroup Polymer Interfaces, TUM Department of Physics, Technical University of Munich) Julija Reitenbach Christina Geiger (Technical University of Munich, Chair of Functional Materials) Dr Lucas Kreuzer (MLZ (FRM II, TUM)) Thomas Saerbeck (Institut Laue-Langevin) Dr Robert Cubitt (Institut Laue-Langevin) Prof. Edmondo M. Benetti (University of Padova) Peter Müller-Buschbaum (TU München, Physik-Department, LS Funktionelle Materialien)

Presentation materials

There are no materials yet.