A transformative formulation approach for generating durable, eco-friendly superhydrophobic coatings

The pervasive use of plastic in packaging presents a significant environmental challenge due to its non-biodegradable nature and continued contribution to global pollution. Superhydrophobic coatings show potential to improve biodegradable alternatives, which often lack the water resistance required to protect from direct liquid contact or exposure to ambient humidity. However, typically, such coatings are prepared from non-biodegradable components in addition to presenting unknown health and safety hazards, particularly in food contact applications. Here, we have developed a novel superhydrophobic coating derived entirely from plant-based materials, offering a sustainable solution to conventional plastic packaging. The coating employs a hydrophobic wax (carnauba) and a roughening agent (lycopodium) to achieve strong water and liquid food repellency, with measured contact angles of 150–162° for water and food-related liquids such as milk, orange juice, cola and honey. Our results demonstrate that through modifying plant-based materials, coatings can maintain hydrophobic stability for over 12 months under both ambient conditions and when exposed to moisture. This work demonstrates a promising pathway towards modifying paper substrates to replace those where plastic is predominantly used, thus advancing sustainable materials for packaging and other related fields.