Self-assembling superstructures of cyclosiloxane amphiphiles with complex flower shapes and superhydrophobic properties

Abstract

Complex flower-shaped superstructures (FSSs) have rarely been reported in pure organic systems with a single soft organic molecule without rigid skeletons. Herein, simple self-assembled complex FSSs using amphiphilic organic cyclosiloxane amphiphiles are obtained through a drop-casting solution process. The synergetic effect of amide–amide hydrogen bonding/alkyl hydrophobic interactions can be tuned to generate “flower petals” with either straight ligulate or curved-plate rosaceous corolla shapes. The step-wise petal formation process is also investigated using scanning electron microscopy. Furthermore, FSSs with different petal shapes with varying surface “wettabilities” are demonstrated. The ligulate-like structure forms a networked porous surface that can suspend water droplets with a non-wet contact mode, i.e., a slippery superhydrophoborphobic surface. The surface of the rosaceous corolla petals exhibits a wet-contact mode with respect to the water droplet with sticky superhydrophobicity. The results play a significant role in understanding the structure and properties of self-assembled FSSs, thereby shedding new light on developing new hierarchical materials from soft organic amphiphiles in the future.