Two-Step Process To Create “Roll-Off” Superamphiphobic Paper Surfaces

Abstract

Surface modification of cellulose-based paper, which displays roll-off properties for water and oils (surface tension ≥23.8 mN·m) and good repellency toward n-heptane (20.1 mN·m), is reported. Droplets of water, diiodomethane, motor oil, hexadecane, and decane all "bead up", i.e., exhibit high contact angles, and roll off the treated surface under the influence of gravity. Unlike widely used approaches that rely on the deposition of nanoparticles or electrospun nanofibers to create superamphiphobic surfaces, our method generates a hierarchical structure as an inherent property of the substrate and displays good adhesion between the film and substrate. The two-step combination of plasma etching and vapor deposition used in this study enables fine-tuning of the nanoscale roughness and thereby facilitates enhanced fundamental understanding of the effect of micro- and nanoscale roughness on the paper wetting properties. The surfaces maintain their "roll-off" properties after dynamic impact tests, demonstrating their mechanical robustness. Furthermore, the superamphiphobic paper has high gas permeability due to pore-volume enhancement by plasma etching but maintains the mechanical flexibility and strength of untreated paper, despite the presence of nanostructures. The unique combination of the chemical and physical properties of the resulting superamphiphobic paper is of practical interest for a range of applications such as breathable and disposable medical apparel, antifouling biomedical devices, antifingerprint paper, liquid packaging, microfluidic devices, and medical testing strips through a simple surface etching plus coating process.

Ultrafast Processing of Hierarchical Nanotexture for a Transparent Superamphiphobic Coating with Extremely Low Roll‐Off Angle and High Impalement Pressure

“…The superamphiphobic coating developed here shows extremely low interaction with water and even with n‐ hexadecane. To our knowledge, the lowest roll‐off angles reported for n‐ hexadecane on superamphiphobic surfaces are 2°–5° depending on the surface and the drop size . Here, 10 µL drops of n‐ hexadecane typically rolled off the surface as soon as the goniometer needle tip was detached although the substrate was adjusted in horizontal plane without any apparent inclination angle (Video S2, Supporting Information).…”

“…After this, superamphiphobic surfaces have been in spotlight of research both from the fundamental and economical aspects. Full comprehension of the super liquid‐repellency mechanisms is a prerequisite to realize the potential of superamphiphobic surfaces in applications ranging from protective and self‐cleaning materials to medical devices and gas exchange membranes . In many of the applications, such as wind screens, window panes, lenses, or protective goggles, the superamphiphobic coating should be optically transparent, mechanically stable, and capable of repelling liquid impalement even under high hydrostatic pressure or drop impact …”

Multilevel Nanoparticles Coatings with Excellent Liquid Repellency

“…Under the condition of 7 vol% of SiO 2 in TiO 2 , the prepared coatings show smooth, crack‐free surface morphology and low surface roughness. Jiang et al who focused on superamphiphobic paper covered the progress in all aspects of durability for the surface by generating a hierarchical structure as an inherent property of the substrate and displaying good adhesion between the film and substrate. The paper wetting properties can be fine‐tuned the nanoscale roughness using the method of a two‐step combination of plasma etching and vapor deposition.…”

The Fracture of Plasma-Treated Polyurethane Surface under Fatigue Loading

“…Metals, ceramics and stiff polymers are widely used materials for such applications. Considerable applied studies are focused on the plasma modification of products with complex three-dimensional shape [2] and/or small size. One of the most important areas of research is the effect of plasma treatment on the biomedical characteristics of materials (antibacterial properties, thrombogenesis, biocompatibility, friction, drug transport) [3].…”