Advances in Sol-Gel-Based Superhydrophobic Coatings for Wood: A Review

Abstract

As the focus of architecture, furniture, and other fields, wood has attracted extensive attention for its many advantages, such as environmental friendliness and excellent mechanical properties. Inspired by the wetting model of natural lotus leaves, researchers prepared superhydrophobic coatings with strong mechanical properties and good durability on the modified wood surface. The prepared superhydrophobic coating has achieved functions such as oil-water separation and self-cleaning. At present, some methods such as the sol-gel method, the etching method, graft copolymerization, and the layer-by-layer self-assembly method can be used to prepare superhydrophobic surfaces, which are widely used in biology, the textile industry, national defense, the military industry, and many other fields. However, most methods for preparing superhydrophobic coatings on wood surfaces are limited by reaction conditions and process control, with low coating preparation efficiency and insufficiently fine nanostructures. The sol-gel process is suitable for large-scale industrial production due to its simple preparation method, easy process control, and low cost. In this paper, the research progress on wood superhydrophobic coatings is summarized. Taking the sol-gel method with silicide as an example, the preparation methods of superhydrophobic coatings on wood surfaces under different acid-base catalysis processes are discussed in detail. The latest progress in the preparation of superhydrophobic coatings by the sol-gel method at home and abroad is reviewed, and the future development of superhydrophobic surfaces is prospected.

Superhydrophobic Non-Metallic Surfaces with Multiscale Nano/Micro-Structure: Fabrication and Application

“…In addition, the superhydrophobic properties can also be further enhanced or functionalized through chemical modification. The sol-gel method offers a well-established route for creating superhydrophobic surfaces on non-metallic substrates [58]. Despite limitations in morphology controllability through spraying or dipping [59,60], it still provides a versatile platform for doping new materials and is compatible with various substrates [61][62][63], enhancing the possibilities of the surface design.…”

A Wooden Carbon-Based Photocatalyst for Water Treatment

“…In the second stage, the particles react with each other to form cross-linked 3-D polymer chains, which are converted into gels. Namely, there are three main steps: solvation, hydrolysis and polycondensation [123,124]. One example is that granular anatase or rutile TiO 2 is impregnated on the surface of biochar to form TiO 2 -BSP [125,126].…”

Siloxane-Modified UV-Curable Castor-Oil-Based Waterborne Polyurethane Superhydrophobic Coatings

“…Superhydrophobic coatings are a special class of coatings whose properties, like those of the lotus leaf [1], prevent water droplets from spreading to wet the surface of an object and instead ensure that the droplets roll freely off the surface. Therefore, superhydrophobic coatings have a wide range of potential applications, such as in self-cleaning, anti-icing, and anti-corrosion applications [2,3].…”