Synthesis of Hydrophobic and Hydrophilic Graphitic Carbon Nanofiber Polymer Brushes

Herringbone graphitic carbon nanofiber (GCNF)−polymer brushes are prepared by atom transfer radical polymerization (ATRP) using the “grafted-from” synthesis strategy. Polymerization of acrylate esters occurs at surface sites covalently derivatized with ATRP initiators to form GCNF−poly( n -butyl acrylate), GCNF−poly(isobutyl methacrylate), and GCNF−poly( tert -butyl acrylate) polymer brushes. Acid hydrolysis of the GCNF−poly( tert -butyl acrylate) polymer brush gives a GCNF−poly(acrylic acid) polymer brush. Solution dispersibilities of GCNF−polymer brushes are controlled by the solubility properties of the polymer brush component, with GCNF−poly(acrylate ester) brushes being hydrophobic, whereas the GCNF−poly(acrylic acid) brush is hydrophilic. Because of the unique atomic structure of GCNFs, a high surface density (ca. 3 chains/10 nm 2 of GCNF surface) of polymer brush functionalization is realized.