ToF-SIMS and XPS study of sulphur on carbon black surface

Abstract

A very broad range of carbon blacks (CB) from different origins and different manufacturing processes (furnace CB, plasma CB, acetylene CB, plasma-treated CB, etc.) were analyzed by surface-sensitive techniques: time-of-flight secondary ion mass spectrometry (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The data were compared with conventional bulk properties of industrial CB: specific surface area and sulphur titration. Different types of sulphur functional groups were identified at CB surfaces by ToF-SIMS (HS-, SOx-, HSOx-, SCN-, etc.). A linear relationship between the ToF-SIMS intensity of the sulphur-containing ions and the total sulphur bulk quantity was observed. The total intensity of ToF-SIMS spectra was found to be dependent on the specific surface area of the CB samples. The total quantity of sulphur measured by XPS, when detected, was in good agreement with the total sulphur bulk quantity. However, the ToF-SIMS sensitivity for sulphur functional groups was much higher than the XPS sensitivity.