Pore development process according to burn-off of activated carbon black with CO2 gas

Abstract

This study examined the pore development of carbon black according to burn-off (BO) ratio of carbon black activated in CO2atmosphere. A horizontal tube furnace was charged with carbon black when the internal temperature reached 1000 °C, and activation time was adjusted to obtain BO ratios of 7.2%, 15.4%, 30.4%, 48.2%, 59.9%, and 83.2%. SEM observations showed that the primary particles of carbon black were aggregated, and varying BO ratios did not cause significant differences in shape and size. Carbon black was presumed to contain pores since the size of primary particles remained largely the same with varying BO ratios, and TEM observation revealed that pores existed within primary particles. The nitrogen adsorption isotherms were of type IV, which is characterized by a hysteresis loop. The specific surface area of raw carbon black was 61.4 m2/g, while that of BO at 83.2% increased 18.0 times to 1107.6 m2/g.