No abstract

Recent studies of carbon oxidation by scanning tunneling microscopy indicate that measured rates of carbon oxidation can be affected by randomly distributed defects in the carbon structure, which ®ary in size. Ne®ertheless, the impact of this obser®ation on the analysis or modeling of the oxidation rate has not been critically assessed. This work focuses on the stochastic analysis of the dynamics of carbon clusters' con®ersions during the oxidation of a carbon sheet. According to the classic model of Nagle and Strick-( ) land-Constable NSC , two classes of carbon clusters are in®ol®ed in three types of reactions: gasification of basal-carbon clusters, gasification of edge-carbon clusters, and con®ersion of the edge-carbon clusters to the basal-carbon clusters due to thermal annealing. To accommodate the dilution of basal clusters, howe®er, the NSC model is modified for the later stage of oxidation in this work. Master equations go®erning the numbers of three classes of carbon clusters, basal, edge and gasified, are formulated from stochastic population balance. The stochastic pathways of the three different classes of carbon during oxidation, that is, their means and the fluctuations around these means, ha®e been numerically simulated independently by the algorithm deri®ed from the master equations, as well as by an e®ent-dri®en Monte Carlo algorithm. Both algorithms ha®e gi®en rise to identical results.