Processing Hydrophilic Poplar Wood into Durably Superhydrophobic Materials with High Stability and Self-Cleaning Properties
Dan Luo, Lingcheng Wang, Yuanqiang Liu, Changtong Mei, Tiantian Yang
Abstract
Natural hydrophilicity affects the service value and life of wood. This study reported a new approach to converting hydrophilic wood into durably superhydrophobic materials without adding low-surface-energy substances. By spraying furfuryl alcohol prepolymer mixed with TiO 2 nanoparticles, a micronano rough structure was firmly constructed on the PFA/TiO 2 wood surface. The superhydrophobic surface was achieved, suggested by a dynamic rolling angle of 4.8° and a contact angle of 159.6°, which was higher than that of some superhydrophobic surfaces fabricated with low-surface-energy substances. Besides, PFA/TiO 2 wood presented excellent resistance to mechanical abrasion, tape peeling, UV radiation, ultrasonic effects, and knife scratching, showing durable superhydrophobicity. This was mainly because ① polymerized furfural resin covered voids and sorption sites of wood and behaved as barriers to external factors indicated by scanning electron microscopy–energy-dispersive spectroscopy (SEM–EDS); ② Nano-TiO 2 was tightly fixed under the action of furfural resin, and the micronano rough structures were preserved well, as suggested by atomic force microscopy (AFM) analysis; and ③ the uniformly distributed nano-TiO 2 revealed by SEM–EDS and X-ray photoelectron spectroscopy (XPS) analysis increased UV shielding properties. Moreover, PFA/TiO 2 wood exhibited remarkable self-cleaning performances and functionality of facilitating UV degradation of oleic acid and improved dimensional stability. The fabrication and mechanism analysis of superhydrophobic material provided references for sustainably upgrading low-quality wood.