Tailorable and scalable production of eco-friendly lignin micro-nanospheres and their application in functional superhydrophobic coating

Exploring the tailorable and scalable production method of lignin micro-nanospheres (LMNS) have a significant meaning for expanding their application field. In this study, the fabrication of LMNS with a wide size-controlled range (∼30 nm to ∼3 μm) and high solid content (8 mg mL−1) by dynamics regulation in a γ-valerolactone/water binary system was reported. The LMNS could be controllably fabricated from nano to micron-scale by synergistically regulating four main dynamics factors, i.e., initial lignin concentration, lignin solution/water ratio, temperature of lignin solution and water, and sonication time. Moreover, the uniformity of the LMNS was effectively improved by centrifugation. The as-fabricated LMNS were further used to fabricate functional superhydrophobic coating on the surface of wood, with a water contact angle of 164.4° and a sliding angle of 5°. The coating showed excellent mechanical and chemical stability in a series of tests, especially good resistance to organic solvent. The coating also exhibited great photothermal effect, suggesting potential application in high-efficient deicing and antibacterial. This study not only provides a green and effective strategy for tailorable and scalable production of LMNS, but also presents an innovative concept for LMNS to fabricate the functional superhydrophobic coatings with organic solvent resistance and photothermal effect.