Patchy Nanofibers from the Thin Film Self‐Assembly of a Conjugated Diblock Copolymer

Abstract

An unexpected morphology comprising patchy nanofibers can be accessed from the self-assembly of an all-conjugated, polyselenophene-block-polythiophene copolymer. This morphology consists of very small (<10 nm), polythiophene- and polyselenophene-rich domains and is unprecedented for both conjugated polymers and diblock copolymers in general. We propose that the patchy morphology occurs from the enhanced miscibility of the blocks arising from the longer alkyl chains in comparison to similar block copolymers with shorter alkyl chains, which fully phase separate, as well as the difference in rigidity between the polythiophene and polyselenophene blocks. This work demonstrates a facile way to tune the self-assembly behavior of conjugated block copolymers by modification of the side chain substituents.

Applying Heteroatom Substitution in Organic Photovoltaics

“…For solution‐processed OPVs deposition conditions have been widely examined using variations in concentrations, substrate and solution temperature, solvents, D‐A ratios, and the addition of various additives . Chemical modifications are used to either modify absorption and charge transport or to alter packing and morphology . The latter set of changes often includes the addition of solubilizing alkyl chains and the introduction of motifs to alternatingly twist or planarize backbones which helps control aggregation and mixing of the respective D‐A components.…”

Synthesis of polymeric organic semiconductors using semifluorinated polymer precursors

“…These properties may be advantageous for applications in self‐assembled materials, however, in which block copolymer micelles with a soluble corona and an insoluble core are desired. Indeed, the self‐assembly of thiophene‐containing block copolymers has been used to create many complex nanostructured materials, including fluorescent nanobeads, micellar fibers of controlled length, and “block co‐micelles” by crystallization‐driven self‐assembly …”

Chemical Institute of Canada and Canadian Society for Chemistry Awards

“…Seferos is interested in electronic processes that take place in organic materials. His report on the self‐assembly of conjugated diblock copolymers is published in this issue …”