Heat‐Set Supramolecular Hydrogelation by Regulating the Hydrophilic–Lipophilic Balance for a Tunable Circularly Polarized Luminescent Switch

Abstract Heat‐set supramolecular gels exhibited totally opposite phase behaviors of dissolution upon cooling and gelation on heating. They are commonly discovered by chance and their rational design remains a great challenge. Herein, a rational design strategy is proposed to realize heat‐set supramolecular hydrogelation through regulation of the hydrophilic–lipophilic balance of the system. A newly synthesized amphiphile hydrogelator with pyrene embedded in its lipophilic terminal can self‐assemble into a hydrogel through a heating and cooling cycle. However, the host–guest complex of the gelator and hydrophilic γ‐cyclodextrin (γ‐CyD) results in a sol at room temperature. Thus, heat‐set hydrogelation is realized from the sol state in a controllable manner. Heat‐set gelation mechanism is revealed by exploring critical heat‐set supramolecular gelation and the related findings provide a general strategy for developing new functional molecular gels with tunable hydrophilic–lipophilic balance.