Functionalization of carbon nanofibers by a Diels-Alder addition reaction.

This paper reports functionalization of CNF via a Diels-Alder addition reaction and the characterization of the obtained materials. The functionalization was assessed by a calorimetric technique (DSC) and the morphology of CNF modified materials was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The functionalization was observed to be dependent on the preparative conditions. Detailed analysis of the CNF modified material surface using TEM, shows a deposited layer homogeneously distributed over the CNF structures with an average thickness of about 15 nm. Finally the chemical activity of the raw CNF and functionalized CNF was analyzed to determine the pH of the point of zero charge (pHpzc) values. The results obtained showed that the functionalized CNF materials presented enhanced acid activity comparatively with the modified carbonaceous materials reported in literature.