Fabrication of Colorful Superhydrophobic Coatings Based on Nanocellulose With Oil/Water Separation and Self‐Cleaning Properties

ABSTRACT Lack of color diversity results in the limited application of most superhydrophobic materials. Nanocellulose, a renewable biomass material with wide sources and excellent properties, has garnered significant research interest in superhydrophobic areas. Its excellent colorability provides favorable conditions for constructing colorful superhydrophobic materials. In this study, we introduced a method for fabricating colorful nanocellulose‐based superhydrophobic coatings. Nanocellulose was dyed and constructed into micron–nanometer composite structure particles, which were modified by silanization and finally obtained colorful nanocellulose particles with superhydrophobicity. Then, the modified particles were mixed with polydimethylsiloxane (PDMS) proportionally to formulate the coatings, which could be sprayed on filter papers to obtain the colorful superhydrophobic surface. This coating could draw a variety of colorful patterns and exhibit self‐cleaning properties with water contact angle of 156.6°. Because of its special surface wettability, colorful superhydrophobic coatings could also be used to efficiently separate oil–water mixtures. In addition, the obtained coatings also had good durability. After 70 frictions by the weights, the contact angle was still maintained at 150.7°. This preparation method was simple and mild preserving the inherent advantages of nanocellulose and introducing a diversity of colors. It offered a novel approach to personalized and multifaceted applications of superhydrophobic materials.