Block copolymer self-assembly: Polydisperse corona-forming blocks leading to uniform morphologies

Abstract

<h2>Summary</h2> Bottom-up block copolymer (BCP) self-assembly involving crystallization of the core-forming block can lead, via a multistep protocol, to a range of uniform structures. One normally works with polymers of narrow molecular weight distribution, at low concentrations, and several steps are necessary because one has to separate the nucleation and growth steps. Here, we show that BCPs with polydisperse corona chains enable one to obtain a broad range of uniform structures in a single pot via a single heating-cooling-aging process, in which the nature of the structures is determined by the solvents and the annealing temperature. Most of the sample dissolves upon heating, but a fraction of the components in the mixture with the smallest corona/core block ratio persists as crystallites and, upon cooling, nucleates the growth of the more soluble components. Remarkably, this one-pot self-assembly can be scaled up to a concentration of 12% w/w, opening the door to useful applications.