Development of a highly transparent superamphiphobic plastic sheet by nanoparticle and chemical coating

Robust Superamphiphobic Coating Applied to Grease-Proof Mining Transformer Components

The iron core and heat sink in a mining transformer are susceptible to damage from oil spills or the harsh mine environment; the deterioration of oil products in the underground environment and transformers produce massive amounts of harmful liquid substances, which may lead to unnecessary economic losses in drilling engineering. To overcome this issue, a convenient and economical way to protect transformer components was developed. Herein, we proposed an air spray technology at room temperature for the preparation of antigreasy superamphiphobic coatings, which are suitable for bulk metallic glass transformer cores and ST13 heat sinks. The addition of polypyrrole powder effectively improves the thermal conductivity and specific heat of the coating in the range of 50-70 °C. More importantly, the fabricated coating has excellent repellency to liquids, such as water, ethylene glycerol, hexadecane, and rapeseed oil. Meanwhile, the coating has excellent physical and chemical resistance and outstanding antifouling features, which provide a feasible solution for combating grease pollution and corrosion in the mine environment. Taking multifaceted stability into consideration, this work contributes to enhancing the application of superamphiphobic coatings in the fields of protecting transformer components in the harsh environment or during transformer operation faults.

Effects of Carbon Templates in Tetraethyl Orthosilicate-Derived Superhydrophobic Coatings

Superhydrophobic coatings have garnered significant research interest due to their potential applications in areas such as ant-icing and windows. This study focuses on the development of superhydrophobic coatings using air-assisted electrospray and the effect of different carbon additives as templates in the coating. Carbon templates, with their unique topological varieties, offer a cost-effective alternative to other patterning technologies such as photolithography. By introducing dispersed carbon black, carbon nanotubes, and graphene additives in TEOS solution, silica is given the ability of localized secondary growth on or around the carbon surfaces as well as the building structure to provide adequate roughness on the substrate surface. The templated silica formations provide a thin coating with nano-scale roughness for heightened water resistance. As compared with the template-free coating that has small silica particles, a surface roughness of 135 nm, and a water contact angle (WCA) of 101.6° (non-superhydrophobic), the carbon templating effect allowed for increased silica particle size, a surface roughness as high as 845 nm, a WCA above 160°, and the ability to maintain superhydrophobicity over 30 abrasion cycles. The morphological characteristics that resulted from the templating effect correlate directly with heightened performance of the coatings. Herein, the carbon additives have been found to serve as cheap and effective templates for silica formation in thin TEOS-derived superhydrophobic coatings.

Two-Step Process To Create "Roll-Off" Superamphiphobic Paper Surfaces

Surface modification of cellulose-based paper, which displays roll-off properties for water and oils (surface tension ≥23.8 mN·m^-1) and good repellency toward n-heptane (20.1 mN·m^-1), 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.