CONFIGURATIONAL CHARACTERISTICS AND SCALING BEHAVIOR OF STARBURST MOLECULES - A COMPUTATIONAL STUDY

The growth of starburst molecules having trifunctional branch points and flexible spacers of Ρ (= 1, 3, 5, 7, 9, and 11) steps are studied by a computer simulation. A self-avoiding walk algorithm is employed to kinetically grow the molecules. The center-to-branch-end distance is found to scale with the radius-of-gyration of the molecule throughout growth. Intramolecular density profiles indicate that the ends of the branches traverse the entire molecule and are not confined to its surface. This branch growth behavior indicates highly folded branches throughout all stages of growth. In general, kinetically grown models of starburst molecules behave as modified Cayley trees. The radius of gyration, R, of the molecule is found to scale with the molecular weight M and the spacer length Ρ according to Rg ~ MνPβ. The exponents β and ν change throughout growth with ν = 0.22 ± 0.02 and β = 0.50 ± 0.02 m the high molecular weight scaling region. © 1990, American Chemical Society. All rights reserved.