On complex structure of local free volume in bond fluctuation model of polymer matrix

Complex dynamics in model polymer-based host-guest systems is ascribed to jamming effects resulting from inhomogeneous dynamics of local free volume in polymer matrix. As a first step towards quantification of this assumption we study the local free volume in static configurations in Monte Carlo Bond Fluctuation Model (BFM), using specially devised local free volume parameter V. Statistical analysis, including various correlation functions and probabilistic distributions, yields a quantitative characterization of a typical equilibrium local volume configuration V ((r) over right arrow) on large, intermediate and local scales. Two types of spatial organizations of local free volume are found and characterized: a liquid-like, constrained by steric interactions, and local voids nearly free of monomers. Those voids form large scale-free clusters with power-law distribution of sizes and complex fractal structure with fractal dimension dependent on cluster's size. The emerging physical picture offers a promising starting point for the characterization of inhomogeneous dynamics of local free volume in BFM and of guest molecules embedded in local volume mosaic states of BFM.