Beech wood cross sections as natural templates to fabricate superhydrophobic surfaces
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Inspired by the hierarchical and porous wood microstructure, polydimethylsiloxane (PDMS)-positive replicas of beech (Fagus sylvatica) cross sections, with superhydrophobic properties, were fabricated. Microtomed transverse sections of beech wood were directly used as templates, and an accurate replication of the anatomical wood features (vessels and fibers) was obtained. The resulting PDMS-positive replicas show an arrangement of pillars, contributing to surface structuration. By adjusting the PDMS pre-curing time, the extent of PDMS penetration could be controlled inside the wood capillaries, inducing the formation of pillars with various aspect ratios. The wettability of the templated surfaces as a function of the different pillars heights was studied, and the optimal pillar aspect ratio was identified to enhance the hydrophobicity of the PDMS structured surfaces (reaching a water contact angle of 156°). Fagus sylvatica wood cross sections are therefore simple, scalable, and inexpensive templates to manufacture structured surfaces, with the possibility to adjust wettability according to application needs.
The authors would like to thank the China Scholarship Council (CSC) for funding, Stéphane Croptier and Thomas Schnider from the Wood Materials Science group in ETH Zürich for discussions on wood species and for their help in wood samples preparation, respectively. We are grateful to the Scientific Center for Optical and Electron Microscopy (ScopeM) at ETH Zürich for the SEM studies.
The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.
Yaru Wang is financed by the Chinas Scholarship Council.
- Guo H et al (2017) Bio-inspired superhydrophobic and omniphobic wood surfaces advanced materials. Interfaces 4:1600289Google Scholar
- Kiaei M, Samariha A (2011) Fiber dimensions, physical and mechanical properties of five important hardwood plants. Indian J Sci Technol 4:1460–1463Google Scholar
- Nosonovsky M, Bhushan B (2008) Lotus-effect and water-repellent surfaces in nature multiscale dissipative mechanisms and hierarchical surfaces: friction, superhydrophobicity, and biomimetics, pp 181–197Google Scholar
- Sylgard 184: viscosity increase during cure. Sandia National Laboratories. https://www.sandia.gov/polymer-properties/E1-viscosity.html. 01.10. 2018