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.