SGER: A Novel Process for Preparing Exfoliated Graphite Layers Using Supercritical Fluids

Wayne State University, Detroit MI

Investigators

Abstract

ABSTRACT: (SGER: A Novel Process for Preparing Exfoliated Graphite Layers using Supercritical Fluids) A key challenge to developing new applications for nanocomposites is to find ways to efficiently disperse the composite filler, in order to produce an exfoliated structure. Conventional methods for preparing exfoliated graphite require extreme temperature conditions and long-term acid treatment. In this proposal a novel technique for preparing expanded/exfoliated graphite by using supercritical fluids as a processing aid, is described. This method includes contacting the graphite structure and a supercritical carbon dioxide (scCO2) soluble organic material such as polymer, oil, or monomer with scCO2 for a certain time. At the elevated pressures, the organics dissolve in scCO2 and diffuse between the layers. The solubility of organics drastically drops during depressurization causing it to deposit on the graphite layer surface. If sufficient amount of coating agent is introduced in the scCO2, each layer surface is coated, and the weak bonds between the layers cannot reform. Preliminary results have been encouraging. The proposal may lead to novel, superior graphite-based, nanostructured materials.