Dartmouth Events

Abstract: The incorporation of very small volume fractions of nanoscale graphitic particles to varied base materials has been explored across many fields ranging from automotive to aerospace to commercial plastics with the goal of utilizing their enhanced thermal conductivity, electrical conductivity or mechanical strength. The use of homogeneous fractions of length or chirality sorted nanotubes affords the study of unique network behavior attributed to them in thin films, melts and solutions. In engineering the mechanical properties of thin films and composites using these nanoscale components, we seek to meet the needs of next generation materials processing and technology development; which are now even more multifaceted, requiring “smart” diagnostic features from components that are mechanically stronger, while remaining viscous neutral during processing, but capable of sensing for non-destructive failure diagnostics on the product end, and are energy efficient. We are at a new frontier at which manipulating nano scale components into unique architectures is achievable and percolation, the ability to form a connected network to allow electrical conductivity for example, is key to developing these next generation smart materials. We have found that near the percolation threshold, the conductivity exhibits a power law dependence on the network geometrical parameters. I will present evaluations of incorporating these single-walled carbon nanotubes into thin film networks in terms of optical transparency, conductivity and noise spectrum at critical percolation concentrations. Also, I will present an evaluation of their network non-linear elasticity, which is modeled as a shift in percolation threshold, generated by strain-induced nanotube alignment, en route to demonstrating modified nanotubes in polymers for decreased viscosity applications.