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Robust siloxane/polyurea coatings combine superhydrophobicity with mechanical durability
A newly developed siloxane/polyurea coating combines microphase separation and an epoxy armour layer to achieve long-lasting superhydrophobic performance under mechanical and chemical stress.
Researchers have introduced a siloxane/polyurea-based superhydrophobic coating with enhanced durability, created through a microphase separation approach and reinforced with an epoxy armour protection layer. Published in Progress in Organic Coatings (Volume 200, March 2025), the study addresses the key challenge of mechanical robustness in practical applications of water-repellent surfaces.
The coating design relies on the intrinsic incompatibility between flexible siloxane chains and rigid polyurea segments. This leads to spontaneous microphase separation into distinct microdomains, forming complex surface morphologies. Two coating systems—ATPDMS-IPUA-E and ATPDMS-HPUA-E—were studied, each using aminopropyl-terminated polydimethylsiloxane (ATPDMS) combined with different diisocyanates. Notably, the ATPDMS0.3-HPUA system achieved a contact angle of 154°, indicating excellent water repellency.
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Surface stability under mechanical and chemical stress
To ensure long-term stability, the coatings were embedded with a grooved epoxy armour structure, which preserved the surface roughness and superhydrophobicity during sandpaper abrasion, tape peeling, bending, and impact tests. Even after prolonged immersion in acidic (pH 2) and alkaline (pH 12) solutions for 12 hours, the coatings maintained contact angles above 151°, confirming their superior chemical resistance.
The combination of microphase design and external epoxy protection enables these coatings to meet the demands of real-world applications, from self-cleaning surfaces to protective coatings in aggressive environments.
Source: Guo, Q. et al. Durable siloxane/polyurea superhydrophobic coatings based on microphase separation method and armour protection strategy, Progress in Organic Coatings, Volume 200, March 2025, 108989.
