Fabricating ultra-slippery superhydrophobic multifunctional coatings by one-step calcination of UiO-66@polydimethylsiloxane

A fluorine-free and environmentally friendly ultra-slippery superhydrophobic (USS) coating was successfully prepared through a simple one-step calcination process using UiO-66@polydimethylsiloxane (PDMS) as the precursor. During the calcination process, a composite structure consisting of UiO-66 derived ZrO 2 and oligomers derived from partial decomposition of PDMS endows the coating with excellent slippery superhydrophobicity. The coating exhibits notable anti-condensation performance, which can effectively inhibit water vapor condensation in humid environments and extend the freezing-thawing cycle time of water droplets under low-temperature conditions, while maintaining its stable superhydrophobic properties. Additionally, the USS coating possesses outstanding oil-water separation capability: The stainless-steel mesh modified by the USS coating achieves a separation flux of up to 40000 L h⁻ 1  m⁻ 2 for trichloromethane and retains a separation efficiency of over 90% as well as a WCA exceeding 150° even after 15 cycles. USS-coated cotton fabrics possess superior flame retardancy. By absorbing flame heat and generating a dense char layer, the coating inhibits combustion and cuts down black smoke emission, while keeping the fabric’s structural integrity and superhydrophobicity intact. This work provides a facile, low-energy, and environmentally friendly strategy for the preparation of multifunctional superhydrophobic coatings, overcoming the limitations of complex processes, high-energy consumption, and environmental harm in traditional superhydrophobic coating preparation.