Since the late 1990’s, research has been underway in our group at Michigan State University to investigate the production, fabrication and modification of a new nano-sized carbon material, exfoliated graphite nanoplatelets [xGnP]. The xGnP is fabricated from natural graphite and can be used as a nanoreinforcement for polymers as an alternative to expensive carbon-based nanomaterials. The thickness of the xGnP can be controlled in a range from 1 to 25 nm. The diameter of the platelet can be controlled from the sub-micron level to ten’s of microns. Consequently, the surface area of xGnP can range from ~25 to over several hundred m2/g. Since graphite is the stiffest material found in nature (Young’s Modulus = 1060 MPa), having a modulus several times that of clay, accompanied with excellent electrical and thermal conductivity, the xGnP should have similar properties to carbon-based nanomaterials, including carbon nanotubes, nanofibers, and fullerenes, yet the estimated cost is estimated to be $5/lb or less, which makes the material very attractive. In this research, nylon 6 and nylon 66 composites were prepared with small amounts of xGnP added as reinforcement. for. Evaluation of the properties of the resulting composites compared to other carbon based nanoreinforcements show that the xGnP improves the modulus of better than other commercially available reinforcements at equivalent volume fractions. Electrical conductivity as measured by impedance measurements have shown that the percolation threshold can be modified by altering the size of the xGnP to below 5vol%. Thermal conductivity measurement reveal that a conductivity greater than 4 W/m*K can be achieved for xGnP/nylon nanocomposite. Permeability of oxygen was also improved significantly xGnP to a level comparable to nanoclays.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: May 7, 2006
Pages: 282 - 285
Industry sector: Advanced Materials & Manufacturing
Topicss: Advanced Materials for Engineering Applications, Coatings, Surfaces & Membranes