Nikolay. A. Tikhonov

Study of Different Types of Carbon Fiber Oxidation Kinetics

Results are given for a study of the effect of treatment temperature on oxidation kinetics of carbon fibers of different structure. It is detected that carbon fiber oxidation by oxygen depends on the production process for fiber manufacture, and as a consequence on the nature of its structure, primarily the degree of crystallinity that governs the number of active centers emerging as oxidation initiators. It is established that oxidation of carbon fibers with a relatively low treatment temperature (up to 2000°C) is approximated by an autocatalytic reaction mechanism.

Nanodiamond and Nano-Onion-Like Carbon Oxidation Kinetics

Results are given for a study of the effect of treatment temperature on oxidation kinetics of nanodiamond particles. Kinetic models are compared for oxidation by oxygen of nanodiamond powder previously heat treated at different temperatures. It is established that depending on treatment temperature (600 and 1400°C) the kinetic models of oxidation are different. For a specimen treated at 600°C the best model appeared to be two parallel reactions. Oxidation of a specimen heated at 1400°C proceeds according to a model of a single-stage n-th order oxidation reaction. Differences in kinetic models and oxidation reaction kinetic parameters are due to a change in the nature and morphology of specimens, which is connected with nanodiamond transformation into nano-onion-like carbon during heat treatment at a higher temperature.