Morphology and surface structure of nanocarbon allotropes: a comparative study

Different carbon allotropes, including vulcan carbon, multiwall carbon nanotubes, graphene, and nanodiamonds, were processed by chemical purification and treated in a mixture of H2SO4–HNO3. The materials were characterized by infrared and Raman spectroscopy as well as by scanning and transmission electron microscopy. Oxidative differences are indicated by Raman through the G band (∼1570 cm−1), D band (∼1340 cm−1), and G’ band (∼2684 cm−1). The crystal size (La) and purity, relative to the amorphous carbonaceous material, were studied as well, along with the morphological changes induced by the treatment

Determination of the surface functionality of nanocarbon allotropes by boehm titration

Critical point (CP) in a titration curve to quantify carboxylic, lactonic, and phenolic groups on multi-walled carbon nanotube (CNT) and Vulcan carbon (VC). Titration technique used was Boehm type and tipping point measurement from titration curve was done by second derivative method. The calculation functional groups on nanocarbons (NCs) presents lowest uncertainty previously published. An order of ±10−4meq/g is the precision of the values obtained, one order of magnitude below reported. Both NCs display a high quantity of carboxylic groups created after being treated with regard to the other functional groups generated, mainly for functionalized Vulcan carbon VC-F