Journal of Chemical Physics, Vol.116, No.1, 347-351, 2002
Continuum percolation in athermal mixtures of flexible and rigid macromolecules
An integral equation treatment of connectedness percolation in macromolecular fluids is extended to athermal mixtures of semiflexible and rodlike polymers. The percolation threshold for formation of a geometrically connected network of rodlike particles dispersed in a medium of flexible polymers is investigated as a function of the particle aspect ratio. Results are also presented for a one-component model of identical rodlike particles in the absence of a matrix. The dependence of critical volume fraction on rod aspect ratio is strikingly similar in both instances, and close to that predicted by an analytic thread-chain approximation. The primary effect of explicitly including the athermal, flexible, matrix polymer molecules is a reduction of the critical volume fraction by a factor which depends only weakly on the aspect ratio of the rodlike particles.