Solution and Melts of Barbwire Bottlebrushes: Hierarchical Structure and Scale-Dependent Elasticity

Abstract

We present a scaling theory describing hierarchical structural organization of semidilute solutions and melts of ”barbwire” bottlebrushes. Such macromolecules consist of a long flexible main chain (backbone) and several side chains emanating from each branching point of a backbone in a starlike manner. We investigate local and large scale conformational properties as well as extensional elasticity of barbwire bottlebrushes in a melt and solutions within a broad concentration range. On small length scale depending on the architectural parameters bottlebrushes exhibit either cylindrical or spherical symmetry imposed by excluded volume interactions between side chains. On a larger scale bottlebrushes behave in solution as self-avoiding chains. Upon increasing the solution concentration the excluded volume interactions get screened on progressively decreasing length scales. We identify semidilute solution regimes that differ with respect to power-law dependences of large scale and local conformational propert...