Surface wettability and emission behavior tuned via solvent in a supramolecular self-assembly system based on a naphthalene diimides derivative

A new gelator (1) based on a naphthalene diimide derivative with two adamantane groups was designed and synthesized, to form stable organogels in 1,4-dioxane, DMSO, ethyl acetate, THE/H2O (1/1, v/v), acetone, toluene, methanol and ethanol under the driving force of noncovalent bonding. Gel 1 in toluene exhibited thixotropic properties. The gel could change to a sol by mechanical force, and recover in 5 s. The sol-gel transition process of gel 1 was thoroughly investigated via field emission scanning electron microscopy (FESEM), ultraviolet visible spectra (UV-vis), fluorescence (FL), X-ray powder diffraction (XRD), Fourier Transform Infrared Spectroscop (FTIR) and contact angles (CA). The emission properties and xerogel surface wettability properties could be modulated via the solvent. The supra-hydrophobic surface with the contact angle of 146 degrees was obtained from gel 1 in DMSO and exhibited the characteristic of "lotus-effect". The hydrophobicity of film 1 produced profound effects on the fluorescence intensity and the lifetime of the excited state. This work offers a new way to construct supra-hydrophobicity via self-assembly.