Photostabilisation of an omniphobic, drop-castable surface coating by transformation of a self-assembled supramolecular xerogel into a covalent polymer xerogel

Abstract

Simple drop-casting of a new gelator, incorporating a diacetylene core and fluorous ponytails, yields porous xerogels as surface coatings. The mechanical stability of such coatings is quantified with a self-devised scratch balance, introducing a simple and universal quantification method to compare the stability of μm-scale coatings. The diameters of the pores in the coatings can be controlled by the breath figure effect. The coatings display omniphobicity with static contact angles of up to 139° (water) and 96° (n-decane). The coatings are topochemically polymerised by UV irradiation, enhancing the mechanical stability by up to four times. Simultaneously, the water and n-decane contact angles are increased by about 9° and 4° respectively due to a slight increase in surface roughness.