Parameters affecting morphology and chemical structure of carbon black synthesized by acetylene black process

Abstract

Acetylene black is widely used as a composite in various applications such as electronic devices, electrode materials, pigments, polymer composites, and catalyst supports. Not only its unique property of electrical conductivity but also other properties are required for various applications. The properties of acetylene black mostly depend on its morphological and chemical structures which can be controlled by synthesis parameters or modified by pre- and post-treatment. In this work, we observe the effect of temperature, acetylene concentration, and residence time on morphological and chemical structures of synthesized acetylene black through thermal decomposition process. The results show that, at an initial state, heat energy accelerates the nucleation rate, which provides smaller particles in both of primary and aggregate forms, and induces the reaction over the heated area. Higher temperature condition contributes to the sintering between crystal edges (La) and to the elimination of organic functional groups which totally disappear over 1100 °C. Higher concentration of feedstock generates higher saturated system which drives the collision between molecules and particles. It also induces the nucleation as the effect of temperature. Then, active collisions of particles push the larger size of aggregate structure. The long residence time also expands the growth period of carbon particles which increases the sizes of primary particles, aggregates, and La. In addition, synthesis temperature acts as a key parameter in the formation of acetylene black. The acetylene concentration and residence time slightly affect the acetylene black structure.