Pair distribution function and related properties of star-branched chains

Full Paper: Pair configurations of linear and star-branched chains with F = 4, 8 and 12 arms embedded in the tetrahedral lattice were investigated. Pair data were determined by exact enumeration of all possible pair configurations. When the separation between two (linear) chains reached zero (r --> 0) the pair distribution function g(r) read approximate to0.15 for athermal and approximate to0.6 for theta conditions in full accordance with former work. For star-branched chains, g(r) approached a value zero at small separations for both thermodynamic conditions and the range of g(r) = 0 increased with an increase of the number of arms. As a consequence, the characteristics maximum of g(r) for theta conditions was the more pronounced the larger the number of arms. For stars, the extent to which mean squared dimensions and shape parameters depend on intermolecular distance was similar to that of linear chains, at least in the region of intermediate and large intermolecular separations. transformation of the data into a concentration dependence revealed that with an increase in concentration, the dimensions decreased in the case of athermal solvents while they increased for theta -solvents regardless of the functionality given.