Phase transformations of nanometer size carbon particles in shocked hydrocarbons and explosives

Estimates for the displacement of the phase equilibrium lines for small car bon particles containing from several hundred to several tens of thousands of atoms are made, and an error analysis of the uncertainties in these esti mates is derived and evaluated using available experimental data. Hugoniot calculations for methane, benzene, polyethylene, and polybutene, based on a carbon particle surface energy adjusted equation of state, are in better a greement with shock pressure-volume and temperature data than those obtaine d with a bulk carbon equation of state. The results suggest that carbon par ticles, of order 10(3)-10(4) atoms, can exist in the liquid state at lower temperatures than bulk carbon. (C) 2001 American Institute of Physics.