Pearl-necklace structures of molecular brushes with rigid backbone under poor solvent conditions: A simulation study.
Bottle-brush polymers, where flexible side chains containing N=20 to 50 effective monomers are grafted to a rigid backbone, are studied by molecular dynamics simulations, varying the grafting density σ and the solvent quality. Whereas for poor solvents and large enough σ the molecular brush is a cylindrical object, homogeneous in axial direction, for intermediate values of σ an axially inhomogeneous structure of "pearl-necklace" type is formed. The "pearls," however, have a strongly nonspherical ellipsoidal shape, due to the fact that several side chains cluster together in one pearl, qualitatively consistent with predictions of Sheiko et al. [Eur. Phys. J. E 13, 125 (2004)] We analyze the structure of these pearls and study both the transition to the axially uniform cylinder at high σ and to the trivial pearl-necklace structure at small σ, where each pearl contains a single collapsed chain only.
Theodorakis
P E
PE
Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, Mainz D-55099, Germany. theodora@uni-mainz.de
Paul
W
W
Binder
K
K
D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature
D011108:Polymers; D012997:Solvents