Low-Molecular-Weight Gels: The State of the Art

The Bigger Picture Gels are ubiquitous soft solids that are widely used in everyday life. Most gels are based on polymeric materials, as either entangled biopolymers or covalently crosslinked networks. Low-molecularweight gels, or supramolecular gels, are another fascinating and useful class of gel. Here, the assembly of small molecules into a network immobilizes the solvent. These materials are becoming increasingly common and offer an opportunity to prepare interesting, designed, and responsive systems. Specific areas where we believe that there will be advances include exploiting the process-dependent nature of gelation and systems that utilize multiple gelators to access new properties. Low-molecular-weight gels are currently a hugely important class of materials that are attracting significant interest. These gels are formed when small molecules self-assemble into one-dimensional structures that entangle and cross-link to form a network that is capable of immobilizing the solvent. Here, we critically discuss the current state of the art and highlight two key areas where we believe there is significant untapped potential. The first is the observation that the properties of the gels are highly process dependent, which means that it is possible to access materials with very different properties from a single gelator. Second, using multiple gelators offers the opportunity to prepare materials with a high degree of information content and with a wider range of properties. We aim to spark thought and discussion on these aspects.