The importance of interfacial design at the carbon nanotube/polymer composite interface

This research focuses on the need for interfacial engineering at the carbon nanotube/polymer composite interface in the effort to obtain enhanced mechanical properties. The mechanical properties of multiwall carbon nanotubes (MWNTs)/poly (methyl methacrylate) (PMMA) nanocomposites were studied as a function of both nanotube concentration and surface treatment. One method, plasma enhanced chemical vapor deposition (PECVD), was successfully used to produce a PMMA conformai coating (using methyl methacrylate monomer) on multiwall carbon nanotubes. Excellent suspensions of MWNTs in organic solvents were achieved via the PMMA coating. The coated-MWNTs were dispersed into PMMA via melt mixing and orientation was achieved by melt drawing. The overall set of mechanical properties indicates that while the conformal polymer coating had a significant effect on the mechanical properties at a 1% concentration of nanotubes as compared to the uncoated nanotube composites, suggesting improved interfacial adhesion between the nanotube and the matrix material. However, the mechanical properties of the 1% coated nanotube composite were not significantly better than those for pure PMMA.