Liquid foams of graphene

Abstract

Liquid foams are dispersions of bubbles in a liquid. Bubbles are stabilized by foaming agents that position at the interface between the gas and the liquid. Most foaming agents, such as the commonly used sodium dodecylsulfate, are surfactant molecules with linear or branched chain molecular structures. This thesis presents a new class of liquid foams made with a foaming agent having a sheet molecular structure. In these foams, air bubbles are encapsulated inside graphene shells. The shells have a concentric layered structure made of isophorone diamine modified graphene oxide sheets. The liquid foams of graphene were initially developed as an extractive step in the preparation of graphene-epoxy nanocomposites. Chapter 1 gives an introduction to polymer nanocomposites and graphene. Chapter 2 presents a novel processing method for graphene-epoxy nanocomposites. Chapter 3 deals with the structure, formation mechanism, stability and mechanical properties of the liquid foams of graphene. Chapter 4 reports on materials and methods. Finally, Chapter 5 summarizes the main conclusions of this work and proposes future directions for research.