Flame-Retardant Silanized Boron Nitride Nanosheet-Infused Superhydrophobic Sponges for Oil/Water Separation

Low cost superhydrophobic/superlipophilic sponge with superior flame retardancy is promising for impactful oil/water separation. Herein, a superhydrophobic silanized boron nitride nanosheet-infused sponge (SBNIS) with a water contact angle (WCA) of 165° was fabricated through a facile bioinspired covalent interaction (inspired by the marine mussels). By combining the properties of boron nitride nanosheets (outstanding chemical stability) and silane (intrinsic hydrophobicity), the resultant biomimetic superhydrophobic sponge shows exceptional oil absorb capacity (maximum 99 times of its own weight) and superior stability (over 20 separation cycles) even in extremely harsh circumstances (strong acid, alkali, salt). Notably, the as-fabricated sponge displays excellent flame retardancy and compressive strength, manifesting potential applications in long-term practical operation. Accordingly, this strategy may open an avenue for the rational design of an advanced superhydrophobic sponge with excellent repeatability and stability.