Structure/function correlation of thixotropic additives based on three leaf-like triamide derivatives containing three alkyl-chains

Abstract

The effect of the solvent gelation ability of three leaf-like triamide derivatives, having three 12-hydroxystearyl or octadecyl chains, as thixotropic-induced additives was investigated. Furthermore, the clarification of origin of the physical properties of these compounds was carried out by monolayer investigation on the water surface. The solvent gels formed by the addition of these triamide compounds reflowed on application of external pressure. Two kinds of three leaf-like triamide derivatives achieved nanofiber formation by intermolecular hydrogen bonding in an organic solvent. The nanofiber film of the three leaf-like triamide derivative with an asymmetric carbon (owing to the introduction of a hydroxyl group at the 12th position of the stearyl chain) exhibited chirality because of its structural configuration. The nanofibers of the triamide derivative that exhibited chirality did not grow linearly, and the solvent containing these fibers gelled more efficiently. It was predicted that a more entangled nanofiber aggregate forms a sponge-like structure, which abundantly incorporates the solvent molecules. The influence of the hydrogen bond between the hydroxyl groups at the 12th position of the stearyl chain was evaluated by experiments on the monolayers of the triamides. As a result, only the triamide derivative containing an asymmetric carbon was able to form a nanofiber in the monomolecular layer.