Bio-based coatings with liquid repellency for various applications

In this work, a novel bio-based liquid-repellent coating system was first developed by using 2-mercaptoethanol-modified castor oil (COME) as a coating precursor, polydimethylsiloxane (PDMS) as a liquid-repellent agent, and hexamethoxymethylmelamine (HMMM) as a curing agent. The resultant coatings demonstrate exceptional liquid repellency, and they exhibit striking anti-ink ability and self-cleaning performance. Besides, these bio-based coatings show remarkable repellency against water-borne and oil-borne paints as well as fingerprint liquid, indicating that they can potentially be used for anti-graffiti and anti-fingerprint purposes. Furthermore, due to their remarkable resistance against various corrosive agents, they can be employed to protect substrates against harsh chemical conditions. More strikingly, these coatings can be dyed into various colors without compromising their liquid repellency. Compared with commercial fluorinated amphiphobic coatings, silicone-based coatings, and Never Wet superhydrophobic coatings, these fluoride-free bio-based coatings show incomparable advantages in terms of liquid-repellent performances and application foreground. It is noteworthy that, they are able to maintain liquid repellency even after being subjected to 5000 abrasion cycles, indicative of their remarkable mechanical robustness. Therefore, these newly developed bio-based liquid-repellent coatings are promising for widespread applications.