Photothermal responsive slippery surfaces based on laser-structured graphene@PVDF composites

Photothermal responsive slippery surfaces with switchable superwettability are promising in the fields of biomedicine, self-cleaning, anti-corrosion, and lab-on-a-chip systems. However, the development of a light switchable slippery surface that combines high-performance photothermal materials with hierar-chical microstructures of special orientation remains challenging, which limits the applications in aniso-tropic droplet manipulation. Herein, we demonstrate a photothermal responsive slippery surface based on laser-structured graphene and polyvinylidene difluoride composites (L-G@PVDF) for controllable dro-plet manipulation. The L-G@PVDF film exhibits high light absorption (-95.4%) in the visible and NIR region. After lubricating with paraffin, the resultant surface shows excellent self-healing ability and light-responsive wettability change due to the photothermal effect of L-G@PVDF and the hot melting effect of paraffin. Additionally, by introducing anisotropic grooved structures, the paraffin-infused L-G@PVDF surface displays anisotropic wettability that further affects droplet manipulation under light irradiation. Also, the photothermal responsive slippery property endows the paraffin-infused L-G@PVDF surface with excellent anti-frosting and de-icing capability. Moreover, the smart paraffin-infused L-G@PVDF surface can be combined with a microfluidics chip for light-driven automatic sampling. This study offers insight into the rational design of photothermal responsive slippery surfaces for controllable droplet manipulation.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study presents a photothermal responsive slippery surface based on laser-structured graphene and polyvinylidene difluoride composites (L-G@PVDF) for controllable droplet manipulation, and achieves surface anisotropic wettability by introducing anisotropic grooved structures.