Research paperHow do molecular structures affect gelation properties of supramolecular gels? Insights from low-molecular-weight gelators with different aromatic cores and alkyl chain lengths

In this study, two types of potential low-molecular-weight gelators with different structural features were designed and synthesized. The influence of two structural features (e.g., aromatic core and alkyl chain length) on gel formation, thermal stability, and morphological structures have been thoroughly investigated using various techniques. The gelation tests suggested that the aromatic cores could produce a dramatic influence on gelation. Compared with compounds containing a very small aromatic core (benzene group), compounds containing a much larger aromatic core (1,3,5-triphenylbenzene group) had better gelation ability. The results for thermal stability showed that the alkyl chain length attached to the aromatic core also had an important influence on the gelation behavior. More specifically, increasing the length of alkyl chains of the gelator first enhanced and then decreased the gel-to-sol transition temperature value under identical concentrations. The morphological investigation revealed that organogels were all composed of twist fibrous aggregates with different shapes and dimensions. From the experimental results presented, it can be deduced that the designed gelators should possess a much larger aromatic core and appropriate alkyl chain lengths to achieve highly efficient gelation. These findings provide useful insight into the design of gelators for the development of supramolecular soft materials.

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