Development of gelling agents to harden organic fluids and elucidation of gelation mechanism

Development of low-molecular-mass gelling agents to harden organic fluids and their gelation mechanism are described. The previously reported gelling agents were briefly outlined, and then the properties and gelation mechanism for our gelling agents were mentioned. The examined gelling agents are i) amino acid derivatives, ii) equimolar mixtures of barbituric acid derivatives and 2,4,6-triaminopyrimidine derivatives, iii) cyclo(dipeptide)s, and iv) oligo(a-amino acid)s. The gelation mechanism is as follows; fiber-like aggregates are formed from numerous molecules by intermolecular hydrogen bonding, then they are juxtaposed and interlocked by van der Waals interaction, and finally immobilized organic fluids. The concluded three features that are important in the development of gelling agents are the existence of intermolecular interactions to build up macromolecule-like aggregates, the occurrence of intertwining of the aggregates, and the presence of some factor to prevent the transformation from a metastable gel to a crystalline mass.