Characterization and Modeling of Single-Wall Carbon Nanotube/Polymer Nanocomposites

摘要

Strong single-wall carbon nanotubes (SWNTs) possess very high stiffness and strength. They have potential for use to tailor the material design to reach desired mechanical properties through SWNT nanocomposites. Uniform dispersion is critical to enhance both stiffness and strength. Layer-by-layer assembly technique has been proven to be effective in dispersing SWNT in polymer matrix. This paper will establish the relation between the constituents of the nanocomposites and the Young's modulus. Based on the mechanics of materials and the micromechanics on material stiffnesses, a mixture model is constructed for evaluating effective Young's modulus for polymers reinforced with SWNT with a volume fraction between 0 and 5%. The model yields the same results as determined from Mori-Tanaka approach for dilute SWNT dispersion, but is still valid at higher volume fractions. Several representative nanocomposite models were developed to consider the case of randomly distributed SWNTs in the matrix and numerically analyzed to investigate the effects of SWNT distribution on Young's modulus. Finite element analysis on microstructures with different orientations of carbon tubes were performed to determine the optimum model which is able to characterize the microstructure of SWNT/polymer nanocomposites. The predictive results from the finite element analysis compared reasonably well with the effective Young's modulus of SWNT/Polyelectrolyte nanocomposites with 5% of SWNT loadings from experiments