Superamphiphobic plastrons on wood and their effects on liquid repellence

• Published in: Materials & design 2020-10, Vol.195, p.108974, Article 108974
• Main Authors: Yin, Haiyan, Moghaddam, Maziar Sedighi, Tuominen, Mikko, Eriksson, Mimmi, Järn, Mikael, Dėdinaitė, Andra, Wålinder, Magnus, Swerin, Agne
• Format: Article
• Language: English
• Subjects: Diffusion; Ethylene; Ethylene glycol; Hansen solubility parameters; Liquid sorption; Liquid uptake; Liquids; Modified layer; Nanofilaments; Paraffins; Plastron; Polyols; Roll-off angles; Silicone nanofilaments; Silicones; Solubility; Superamphiphobicity; Superhydrophobicity; Surface modification; Surface-modified; Swelling; Wood; Wood-based products
• ISSN: 0264-1275; 1873-4197; 1873-4197
• DOI: 10.1016/j.matdes.2020.108974

The increasing utilization of wood-based products raises new demands for improved durability, for example an enhanced liquid repellence. Superhydrophobic or superamphiphobic surfaces have been widely fabricated. Less attention has been paid to such modifications on wood and the changes of its hygroscopic or solvoscopic properties. In this work, wood veneers were surface modified by hydrophobized silicone nanofilaments. Results revealed that the surface-modified wood showed a superamphiphobic behavior, i.e. it repelled water, ethylene glycol and hexadecane with contact angles greater than 150° and roll-off angles of less than 10°. Most importantly, a plastron effect was observed when the surface-modified wood was submerged in water, ethylene glycol or hexadecane, which reduced the liquid sorption rate and extent to various degrees. By comparing the measured permeabilities and the estimated diffusive mass flux and supported by Hansen solubility parameters and the degrees of swelling, it is concluded that diffusion is the major cause for the liquid uptake in the surface-modified wood. Moreover, the interaction between the liquid and the modified layer (the solubility of the liquid in the modified layer) also needs to be considered, especially in hexadecane. [Display omitted] •Superamphiphobic wood surfaces were successfully prepared by hydrophobized silicone nanofilaments.•A plastron effect was observed when the surface-modified wood (SMB) was submerged in water, ethylene glycol or hexadecane.•The plastron reduced the liquid uptake of the SMB in hexadecane but not in water under long-time submersion.•The diffusion in the plastron accounts for the major difference in the liquid uptake of SMB.•The interaction between the liquid and the surface layer/solubility contributes to the liquid uptake in hexadecane.