Title Surface Modification of Exfoliated Graphite Nano-Reinforcements
Source Proc. 38th. SAMPE Tech. Conf.,
Year 2006
Author(s) Allred, R. E.; Gosau, J. M.; Barlow, J. P.
Abstract Nano forms of graphite and carbon, such as flakes, worms, and tubes, can significantly modify the properties of polymers when used as reinforcements. Challenges remain in processing composites with these nano-reinforcements in the form of attaining uniform dispersions. Many of these difficulties are due to a lack of wetting of the nano-reinforcements by the polymer. Poor wetting is caused by the very low surface energy of the as-produced graphite nano-reinforcements. Opportunities exist for modifying the surface chemistry and energy of nano-reinforcements that will allow improved wetting and provide a means for chemical bonding at the interface with polymers such as epoxy. Two approaches for surface modification are presented: (1) oxidative plasma treatments to populate the graphite surface with carboxyl and hydroxyl groups, and (2) bonding of epoxy oligomers to the nano-reinforcements using reactive coupling agents. Both of these approaches have proven successful with exfoliated graphite nanoflakes. These unique nano-reinforcements will find many applications in structural composites for military and commercial aircraft, aerospace, chemical processing, and medical structures. The nano-materials markets are projected in the billions of dollars in the next decade, which will provide numerous outlets for the surface modified nano-reinforcements.
Keywords plasma treatment, plasma effects, nano materials, nano structures, nano-reinforcements, polymers, epoxy oligomers, nanoflakes