Lotus plant inspires development of ice and water repellent coatings

A coating material for airplanes, wind turbines and powerlines has been developed using the same mechanics observed in the humble lotus plant.

Scientists from Simon Fraser University have mimicked both the hydrophobic properties of the lotus plant and the slippery properties of pitcher plants together with its material – properties that do not occur in nature simultaneously.

Hua-Zhong Yu, a chemistry professor who led the study, said: “We wanted to explore whether combining the roughness-driven hydrophobicity of lotus leaves with the slippery behavior of pitcher plants could create a surface with enhanced performance.”

Best of both worlds

Combining these two properties in coatings has proven difficult historically due to differences in surface texture.

Sanpreet Kaur, a co-author of the study, said: “Surface roughness can trap air and make a surface superhydrophobic but, once water freezes, that same roughness can actually give ice more places to grip onto the surface.”

To develop icephobicity, many coatings have slippery liquid-infused porous surfaces (SLIPS); however, these surfaces have poor durability as the lubricating liquid in it tends to wear off when exposed to harsh conditions, including wind and rain.

Taking these principles, the scientists developed a new class of SLIPS based on polydimethylsiloxane, a flexible silicone polymer, which they infused with silicone oil and cast in a crystalline mold developed from polycarbonate sheets with acetone.

This produced a material with a water contact angle exceeding 171°, meaning the water droplets interacting with the surface would form perfect spheres while maintaining low ice adhesion.

Stable properties

The researchers found that the nano and microstructures of the material allowed it to retain the silicone oil without ware, making it more stable than typical SLIPS.

Despite the technology showing promise, Yu said that more research is needed to understand the durability of the material and the potential environmental effects of its formulation.

He added: “At small structures, these structures are easy to control, but producing the same roughness and lubricant distribution uniformly across larger surfaces becomes much more difficult.”