SPP 2171 Workshop: "Wetting of Flexible, Adaptive, and Switchable Substrates"

Synthesis of diblock copolymer brush layers to control the adaptation time to water
Benjamin Leibauer1, Andres de los Santos Pereira2, Sajjad Shumaly1, Ognen Pop-Georgievski2, Hans-Jürgen Butt1, Rüdiger Berger1
1 Departement Physics at Interfaces – Max Planck Institute for Polymer Research
2 Institute of Macromolecular Chemistry CAS, Prague
Abstract, SPP 2171 Meeting Berlin, December 2023

The Young’s model describes the wetting behavior of an ideal surface. Recently, Butt et al. presented an adaptation model, which connects adaptation processes of the surface to dynamic contact angles [1]. In order to test the adaptation model, we used a tilted plate setup, which allows measuring velocity dependent contact angles. The applicability of the adaptation model was experimentally verified by Li et al. using surfaces made of statistical copolymers [2,3]. The adaptation model was used to measure the release kinetics of a pH-responsive polymer [4]. In a next step, we synthesize polymer surfaces with the aim to control the adaptation time scale upon wetting and dewetting systematically. We used the surface-initiated atom transfer radical polymerization ATRP to selectively synthesize diblock copolymer brushes. We prepared poly(2-hydroxyethyl methacrylate) (PHEMA) as a hydrophilic block from the surface and we grafted polystyrene (PS)) or Poly(1-hexyl methacrylate) (PEtHexMA) as hydrophobic block on top of the PHEMA block [5]. By regulating the architecture and thickness of the polymer brush we tune the wetting properties. In addition, we control the adaptation time of polymer brush surfaces by changing the drop-sample temperature.
References
[1] Hans-Jürgen Butt✉, Rüdiger Berger, Werner Steffen , Doris Vollmer, and Stefan A. L. Weber, Langmuir, 34, 11292 - 11304 (2018). 10.1021/acs.langmuir.8b01783 …
[2] Xiaomei Li, Simon Silge, Alexander Saal, Gunnar Kircher, Kaloian Koynov, Rüdiger Berger, Hans-Jürgen Butt, Langmuir 37, 1571-1577 (2021). https://doi.org/10.1021/acs.langmuir.0c03226 …
[3] Xiaomei Li, Mirela Encheva, Hans-Jürgen Butt, Ellen H.G. Backus✉ and Rüdiger Berger, Macromol. Rapid Commun. 43, 2100733 (2022). https://doi.org/10.1002/marc.202100733
[4] Xiaomei Li, Krisada Auepattana-Aumrung, Hans-Jürgen Butt, Daniel Crespy, Rüdiger Berger, Chemical Physics Letters 158, 144901 (2023). https://doi.org/10.1063/5.0142928
[5] Benjamin Leibauer, Andres de los Santos Pereira, Ognen Pop-Georgievski, Hans-Jürgen Butt, Rüdiger Berger manuscript in preparation

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