Superhydrophobic corn straw as a versatile platform for oil/water separation

Abstract

Development of advanced oil/water separation materials with durability, versatility, and cost-efficiency in a green manner is highly desired yet still challenging. Herein, to address this challenge, we fabricated an advanced platform for oil/water separation using natural corn straw as a raw material. Superhydrophobic corn straw (SHCS) blocks and filter paper with deposited SHCS powder were fabricated by one-step immersion processes that were simple and cost-efficient. The resulting corn straw-based materials kept their superhydrophobicity after immersing in oil, hand-bending test, abrasion with sandpaper, and even 120 h of UV irradiation. The SHCS block was used as an oil sorbent scaffold to absorb oils from oil/water mixtures selectively; while the SHCS powder deposited filter paper was demonstrated as a membrane to separate oil/water mixtures efficiently even in acidic, alkaline, salty, and high-temperature conditions (more than 80 °C). Importantly, these SHCS-based materials retained their high separation efficiency even after 10 cycles of oil/water separation. Superhydrophobic corn straw that can be used as a versatile platform for oil/water separation was fabricated.