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

Richard Laine

DJ Krug and RM Laine (2017)

ACS Appl. Mater. Interfaces, 9:8378-8383.

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 [PhSiO1.5]12 (DDPS) with octamethylcyclotetrasiloxane (D4). 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 (Td5% ≥ 340 °C in air) due to the siloxane network with a maximum Td5% 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.

Thin film, hybrid materials, silsesquioxanes