Using Heat‐Assisted In Situ Curing of Polydimethylsiloxane to Directly Transform Waste Corn Straw Into an Eco‐Friendly Oleophilic Absorbent With Hydrophobicity, Recyclability, High Oil Retention Capacity, Self‐Cleaning, and Anti‐Fouling Ability

There is a growing interest in how to recycle waste corn straw (CS) more easily, which is still a concern. Turning CS into a high‐value functional absorbent is becoming a good choice. However, the preparation of CS absorbents is still costly, complicated, and unfriendly to the environment. Herein, a facile and eco‐friendly hydrophobic strategy based on in situ curing of polydimethylsiloxane (PDMS) is proposed for obtaining the PDMS‐coated CS oleophilic absorbent. Combining the dip‐coating method and heat treatment can simultaneously achieve hydrophobicity on both the outer surface and inner part of PDMS‐coated CS, which shows outstanding water repellency and good oil–water separation ability. PDMS‐coated CS can absorb different oils and organic solvents and shows excellent recyclability, as well as a high oil retention capacity and good self‐cleaning and anti‐fouling ability. This work provides a simpler preparation method for converting waste agricultural biomass into oil‐absorbing materials.