Spontaneous Adsorption of Graphene Oxide to Oil–Water and Air–Water Interfaces by Adsorption of Hydrotropes

Abstract

The interfacial adsorption of graphene oxide (GO) is crucial in phenomena such as emulsification and froth flotation, where presence of 2D nanomaterials facilitates Pickering stabilization. This process usually requires the input of high amounts of shear energy, or is aided by surfactants in order to make it possible at room temperature. In this work, a surfactant-free method for interfacial enrichment through the use of a family of tetraalkylammonium hydrotropes, the most effective being tetraethylammonium chloride (TEAC), is demonstrated. As both GO and hydrotropes do not spontaneously enrich to interfaces on their own, this synergistic, spontaneous effect highlights that hydrotropes adsor..