Bioinspired Multiscale Structures for Fluorine-Free Superhydrophobic Cellulose Paper with Antifouling and Abrasion Resistance

Superhydrophobic paper has broad demand across multiple sectors, but organic pollution and poor durability hinder its sustainable application. Inspired by natural organisms, fluorine-free superhydrophobic cellulose paper exhibiting self-cleaning and ultra-abrasion resistance is realized through embedded fractal structures that seamlessly integrate hierarchical roughness into the fiber network. Precisely, biomimetic raspberry-like particles are synthesized via one-pot surfactant-free polymerization. Driven by the migration effect, the particles permeate into the cellulose network along with the movement of the aqueous phase, forming micro/submicron/nano hierarchical roughness both on the paper surface and within the paper matrix through redistribution and alkyl ketone dimer (AKD) encapsulation. The formation mechanism of particle topography and the effect of multilevel roughness on superhydrophobic performance are systematically investigated. Under optimal processing, the prepared superhydrophobic paper achieves a water contact angle of 161°, maintaining >120° after 80 cycles of loaded abrasion. Remarkably, the cellulose paper retains its hydrophobicity even after the paper is abraded to the point of perforation, which is reflected in the all-around distribution of biomimetic particles at the damaged area. These findings are expected to offer valuable insights into the bottom-up design of hierarchical rough structures and the sustainable production of ultrarobust superhydrophobic materials.