Controlled Dispersion of Carbon Nanotubes Wrapped in Amphiphilic Block Copolymers: Elaboration of Polymer Nanocomposite

摘要

In this work, we aim to prepare polymer nanocomposites by the dispersion of multiwall carbon nanotube (MWCNT) in aqueous solution using amphiphilic block copolymers. First, we report our success in wrapping MWCNT with amphiphilic block copolymers in aqueous solution. We selected poly(ethylene oxide) (PEO) as the hydrophilic block because of its strong affinity for water and its easiness synthesis, while for hydrophobic block we used one of the following polymers: polyethylene, poly(propylene oxide), polythiophene. The dispersions were characterized by different techniques including optical microscopy (OM) and transmission electron microscopy (TEM), along with UV-visible adsorption and dynamic light scattering. Of particular interest, are our findings related to nanocomposites composed of the PEO or poly(methyl-methacrylate)-wrapped MWCNT. We investigated through of their rheological and electrical (percolation) behavior, about the structure and the dispersion of the nanoparticles in the polymer matrix. In terms of the rheological behavior, both dynamic modulus G' and complex viscosity η~* increased especially at low frequencies as the CNT loading increases. We observed two rheological percolations. Electrical measurements showed one electrical percolation.