Bicontinuous Nanospheres from Simple Amorphous AmphiphilicDiblock Copolymers.

Bicontinuousnanospheres have been observed (although rarely) froma variety of block copolymers with architectural and compositionalcomplexity, and often in the presence of additives. Unlocking keyfeatures involved in their formation presents possibilities for bicontinuousaggregates with varied functionality and application. An attractiveprospect is the ability to form them from much simpler polymeric structuresderived from facile syntheses. To that end, we herein report the formationof bicontinuous aggregates from simple amorphous amphiphilic diblockcopolymers of poly(ethylene oxide)-b-poly(n-butyl methacrylate), analogous to our previous reportof the same from a semicrystalline comb-like block copolymer. Moreover,we demonstrate that polymorphism can be achieved by altering the relativeblock proportions and the nonselective cosolvent. We find that thepolymeric structure is not the dominating factor in the formationof bicontinuous nanospheres but that the choice of cosolvent for thehydrophilic block appears to have greater influence on determiningthe end morphology. [ABSTRACT FROM AUTHOR]