Polymer organogelators that make supramolecular organogels through physical cross-linking and self-assembly

This tutorial review highlights recent and current advances in polymer organogelators, which are rare compared with low molecular weight gelators. In this review, we classify polymer organogelators in three categories: the formation of supramolecular crosslinking points by conformational changes, the addition of crosslinking agents and the self-assembly of gelation-causing segments. Highly stereoregular polymers form a physical gel in organic solvents, involving conformational changes such as helix formation. The addition of cross-linking agents into polymer solutions provides stimuli-sensitive organogels. Furthermore, polymer organogelators, which consist of versatile polymers, such as poly(ethylene glycol)s, polycarbonates, polyesters, polycaprolactones, polyolefins and low molecular weight gelators, function as good organogelators that can form organogels in many organic solvents at low concentration. The organogelation properties of polymer organogelators are significantly affected by the chemical structures of the introduced low molecular weight gelators and polymer backbones, the molecular weight of the polymer backbones and the linking mode between the low molecular weight gelator segment and the polymer.