Controlling Self‐Sorting versus Co‐assembly in Supramolecular Gels

Abstract

Supramolecular gels formed by the combination of different organic molecules are of significant interest in the search of new functional materials. When two different molecules are mixed to form gels, the self-assembled fibres can be a result of self-sorting or co-assembly. A key challenge is to control the network type. Here, we demonstrate that control over the network type can be achieved either by varying the hydrophobicity of a component or by employing a pH-switch method.

Macroscopic volume phase transitions in supramolecular gels directed by covalent crosslinking

“…These results indicate coassembly of 1 and 2. 33 To confirm this, powder X-ray diffraction (PXRD) study of the wet gels was conducted (Figure 2g). In both cases, no sharp diffraction peak was seen, suggesting less ordered molecular packing in the gels.…”

“…In this case, deprotonation of the ammonium group of 2 generates the corresponding amine. 33 Visually, the solution of 2 turned into a gel (pH 10.4) upon addition of equimolar amounts of NaOH (Fig. 2a and Fig.…”

“…S5, ESI †). 33,34 In the gel (1 + 2), the monomer peak was redshifted by 3 nm with a significant increase in the relative intensity of the excimer emission band. These results indicate coassembly of 1 and 2.…”

“…In this case, deprotonation of the ammonium group of 2 generates the corresponding amine. 33 Visually, the solution of 2 turned into a gel (pH 10.4) upon addition of equimolar amounts of NaOH (Figure 2a, Figure S2). The gel consists of spherulitic domains of fibres as observed in confocal and optical microscopy imaging (Figure S2).…”

“…The solution of 2 exhibited a sharp emission at 320 nm with a shoulder band near 365 nm corresponding to the monomer and excimer emissions of the fluorenyl group, respectively (Figure S5). 33,34 In the gel (1+2), the monomer peak was red-shifted by 3 nm with a significant increase in the relative intensity of the excimer emission band. These results indicate coassembly of 1 and 2.…”