Fabrication of a Robust and Flame-Retardant Alooh-Lignocellulose Composite with a Lotus-Leaf-Like Superhydrophobic Coating

Herein, a lotus-leaf-like polydimethylsiloxane coating was printed on the surface of an as-prepared aluminum oxide hydroxide (AlOOH)/lignocellulose composite (ALC) using soft lithography. Compared with pure lignocellulose, the coated ALC exhibited a higher modulus of elasticity and modulus of rupture due to the abundant hydrogen bonds between the fibers and AlOOH nanoparticles (NPs) and the tough layered structure of the fibers. The maximum pyrolysis rate of the coated ALC during differential thermal gravimetry was slower than that of the pure lignocellulose, and the total heat release measured by the cone calorimeter test was reduced by 10.3% compared to the pure material, which confirmed the flame retardant properties of the AlOOH NPs in the ALC. The coated ALC possessed excellent superhydrophobicity with a water contact angle of 152.1 degrees and a sliding angle of 7.4 degrees. The coating was able to durably resist a certain abrasion range, hot soaking and acid/alkali drops.