Supramolecular hydrogel based on amphiphilic calix[4]arene and its application in the synthesis of silica nanotubes

Abstract

Novel amphiphilic calix[4]arenes bearing four carboxylic groups at the upper rim and four alkyl chains at the lower rim were synthesized. It was found for the first time that a hydrogel could form by leaving the suspension of the amphiphilic calix[4]arene in aqueous media to stand at room temperature for a period of time. Unlike most supramolecular gels which result from the aggregation of a solute in hot solution upon cooling, this kind of hydrogel was produced through a dissolution-reassembly process from nanospheres to nanofibers, which could be used as a template for preparation of silica nanotubes.