Abstract
Temperature-driven wetting transition and localized oil entrapment in stimuliresponsive Poly-octadecylmethacrylate brushes
Smart polymer coatings with switchable wettability gained considerable attention due to their potential
in a wide range of industrial applications such as microfluidics, self – cleaning surfaces and controlled
drug delivery. Surface wettability is governed by surface chemistry and morphology and can be
modified by external stimuli such as temperature, light, and pH.
In this study, we explore the switchable wettability of n-alkanes on stimulus-responsive polyoctadecylmethacrylate (P18MA) brushes and introduce a method for reversible oil entrapment using
laser-induced heating with micrometer-scale precision.
Our results reveal a two-stage temperature-driven wetting transition of n-alkanes on these brushes.
Initially, a moderate temperature increase causes the brush layer to swell while maintaining a finite
contact angle of the oil. As the temperature rises further, the oil spreads across the already swollen brush
layer. Combining macroscopic wetting experiments, Atomic Force Microscopy (AFM) adhesion
measurements, and non-linear optical Sum Frequency Generation (SFG) spectroscopy, we show that
this two-stage wetting transition is linked to the initial melting transition of the bulk polymer and a
subsequent, surface-specific melting transition that remains in an ordered state up to a few degrees
above the bulk melting temperature.
Smart polymer coatings with switchable wettability gained considerable attention due to their potential
in a wide range of industrial applications such as microfluidics, self – cleaning surfaces and controlled
drug delivery. Surface wettability is governed by surface chemistry and morphology and can be
modified by external stimuli such as temperature, light, and pH.
In this study, we explore the switchable wettability of n-alkanes on stimulus-responsive polyoctadecylmethacrylate (P18MA) brushes and introduce a method for reversible oil entrapment using
laser-induced heating with micrometer-scale precision.
Our results reveal a two-stage temperature-driven wetting transition of n-alkanes on these brushes.
Initially, a moderate temperature increase causes the brush layer to swell while maintaining a finite
contact angle of the oil. As the temperature rises further, the oil spreads across the already swollen brush
layer. Combining macroscopic wetting experiments, Atomic Force Microscopy (AFM) adhesion
measurements, and non-linear optical Sum Frequency Generation (SFG) spectroscopy, we show that
this two-stage wetting transition is linked to the initial melting transition of the bulk polymer and a
subsequent, surface-specific melting transition that remains in an ordered state up to a few degrees
above the bulk melting temperature.
| Original language | English |
|---|---|
| Publication status | Published - 21 Jan 2025 |
| Event | NWO Physics 2025 - Koningshof, Veldhoven, Netherlands Duration: 21 Jan 2025 → 22 Jan 2025 |
Conference
| Conference | NWO Physics 2025 |
|---|---|
| Country/Territory | Netherlands |
| City | Veldhoven |
| Period | 21/01/25 → 22/01/25 |