Surface functionalization and characterization of graphitic carbon nanofibers (GCNFs) Original Research Article

The preparation and characterization of herringbone graphitic carbon nanofibers (GCNFs) surface-derivatized with reactive linker molecules derived from four diamines and three triamines is reported. Surface carbon sites of as-prepared GCNFs are oxidized to carboxylic acid groups by nitric acid and covalently bound to seven different linker molecules containing pendant amino groups using carboxylate amidation chemistry. GCNF materials are characterized by TEM, IR, TGA, laser-desorption/ionization (LDI) mass spectrometry, and by elemental analysis. Approximate GCNF/(linker molecule)x compositions are proposed consistent with acid-uptake and elemental analysis data. Direct evidence for the presence and composition of surface-bound linker molecules is provided by LDI mass spectrometry and by quantitative XPS analysis of trifluoroacetylated derivatives. The reactivity of pendant amino groups present within attached linker molecules is determined quantitatively via Fmoc analysis and synthetically by effecting nucleophilic ring-opening oligomerization of epoxy monomer.