Elucidating the effects of surface and internal oxidation on material properties of carbon black

Abstract

This paper investigates the effects of surface and internal oxidation of carbon black (CB) using different oxidizing media, such as ozone, hydrogen peroxide, nitric acid, and potassium permanganate, on CB's porosity, crystallite, and functional groups. The study uses various techniques, such as thermogravimetric analysis (TGA), scanning electron microscopy, N2 adsorption, Raman and infrared spectroscopy, X-ray diffraction (XRD), and zeta potential analysis, to analyse the samples. The results show that internal oxidants cause higher changes in the CB's crystallinity and porosity dynamics than surface oxidation, while surface oxidation predominantly occurs at the CB surface interface. The XRD and fractal analysis of the pore network after oxidation indicate that internal oxidation of the crystallites that make up the CB matter reduces the interlayer distance by compacting their pore networks. This study provides a quantitative analysis of the crystallinity and CB porosity dynamics, which can help in the development of highly porous CB that can act as substitutes for higher grades of CB used in polymer products as reinforcement, activated carbons, or as high-end materials in the development of super-capacitors for battery applications.