Work

Thermally Activated Swelling and Wetting Transition of Frozen Polymer Brushes:a New Concept for Surface Functionalization

Year: 2025

Type: article

Abstract: Functional polymer brush coatings have great potential for various industrial applications thanks to their ability to adapt to environmental stimuli, providing tunable surface properties. While existing approaches rely on polymer-solvent interactions and their response to external stimuli, changes in the intrinsic physical properties of the polymer also play a critical role in modulating brush behavior. In this context, the melting transition of a semicrystalline oleophilic poly-octadecylmethacrylate (P18MA) brush coating is shown to drive a swelling and wetting transition upon exposure to various liquid alkanes. The top surface of this polymer displays a somewhat higher melting temperature than the bulk, enabling separate control of the bulk-driven swelling and surface-driven wetting transitions. Laser-induced heating enables reversible on-demand activation of both transitions with micrometer lateral resolution. These findings suggest a new concept of polymer brush-based functional surfaces that allow for controlled fluid transport via separately switchable surface barriers and bulk transport layers based on a suitable choice of polymer-polymer and polymer-solvent interactions.

Source: Advanced Materials

DOI: 10.1002/adma.202502173