Effect of graphite surface modification on the properties of exfoliated graphene oxide/epoxy nanocomposites

I&EC 12

Sandi Miller, Sandi.G.Miller@grc.nasa.gov, Polymeric Materials Branch, NASA, 21000 Brookpark Rd, MS 49-3, Cleveland, OH 44135, Paula Heimann, Paula.J.Heimann@nasa.gov, Polymeric Materials, Ohio Aerospace Institute/ NASA Glenn Research Center, 21000 Brookpark Rd, MS 49-3, Cleveland, OH 44135, and Daniel A. Scheiman, daniel.a.scheiman@nasa.gov, Materials and Structures Division, ASRC Aerospace and NASA Glenn Research Center, 21000 Brookpark Road, M.S. 49-1, Cleveland, OH 44135.
Expanded graphite has recently attracted considerable attention as a nanocomposite material. However, its low surface energy results in poor wetting by a polymer matrix. The strength of the polymer-graphite interface is improved by oxidation of the layered graphene sheets. Additionally, the oxidation process introduces functional groups on the graphene plane, allowing chemical modification of the sheets and optimization of the filler-matrix interface. The purpose of this paper is to investigate the toughness, coefficient of thermal expansion, and thermal conductivity of a series of thermally exfoliated graphene oxide/epoxy nanocomposites. Surface treatments on the graphene oxide include: no treatment, covalent attachment of a surfactant, and use of excess hardener to allow covalent bonding between matrix and graphite. The results show considerable improvement in nanocomposite toughness as the strength of the filler-matrix interface is increased. Improvements in resin dimensional stability were observed for most nanocomposites, and increases in thermal conductivity were obtained.
 

High Performance Composites, Sponsored by Advanced Materials and Nanotechnology Sub-Division
8:30 AM-11:50 AM, Sunday, 10 September 2006 Moscone Center -- Room 252/254, Oral

Division of Industrial & Engineering Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006