Durable and Hydrophobic Organic–Inorganic Hybrid Coatings via Fluoride Rearrangement of Phenyl T₁₂ Silsesquioxane and Siloxanes

There have been many successful efforts to enhance the water shedding properties of hydrophobic and superhydrophobic coatings, but durability is often a secondary concern. Here, we describe durable and hydrophobic coatings prepared via fluoride catalyzed rearrangement reaction of dodecaphenylsilsesquioxane [PhSiO 1.5 ] 12 (DDPS) with octamethylcyclotetrasiloxane (D 4 ). Hydrophobic properties and wear resistance are maximized by incorporating both low surface energy moieties and cross-linkable moieties into the siloxane network. Water contact angles as high as 150 ± 4° were achieved even after 150 wear cycles with SiC sandpaper (2000 grit, 2 kPa). These hybrid organic–inorganic copolymers also have high thermal stabilities after curing at 250 °C ( T d5% ≥ 340 °C in air) due to the siloxane network with a maximum T d5% of >460 °C measured for the system with the highest silsesquioxane content. The coating systems presented here offer a unique combination of hydrophobicity and mechanical/thermal stability and could greatly expand the utility of water repellent coatings.