Toward Uniform Nanofibers with a π‑Conjugated Core: Optimizing the “Living” Crystallization-Driven Self-Assembly of Diblock Copolymers with a Poly(3-octylthiophene) Core-Forming Block Ulrich Tritschler Jessica Gwyther Robert L. Harniman George R. Whittell Mitchell A. Winnik Ian Manners 10.1021/acs.macromol.8b00488.s001 https://acs.figshare.com/articles/journal_contribution/Toward_Uniform_Nanofibers_with_a_Conjugated_Core_Optimizing_the_Living_Crystallization-Driven_Self-Assembly_of_Diblock_Copolymers_with_a_Poly_3-octylthiophene_Core-Forming_Block/6737228 Crystalline poly­(3-alkylthiophene) (P3AT) nanofibers are promising materials for a myriad of device applications, but nanofiber length control and colloidal stability are difficult to achieve. We report an in-depth study of the solution self-assembly of regioregular poly­(3-octylthiophene)-<i>b</i>-poly­(dimethylsiloxane) (P3OT-<i>b</i>-PDMS) diblock copolymers with a crystallizable π-conjugated core-forming block. Use of the “living” crystallization-driven self-assembly (CDSA) seeded-growth method in solvents selective for PDMS allowed access to relatively low length dispersity, colloidally stable P3OT-<i>b</i>-PDMS fiber-like micelles with a crystalline, tape-like P3OT core, a PDMS corona, and lengths up to ca. 600 nm under optimized conditions. Significantly, the presence of a small percentage of common solvent and the use of slightly elevated temperature (35 °C) were found to enhance the length control. Analogous studies for P3OT-<i>b</i>-PS (PS = polystyrene) suggest that solvent composition and temperature represent key parameters for the general optimization of fiber formation by living CDSA for P3AT block copolymers. 2018-07-03 16:29:17 600 nm PDMS fiber-like micelles Diblock Copolymers length dispersity P 3AT nanofibers P 3OT b core-forming block crystallizable π- tape-like P 3OT core diblock copolymers P 3AT block copolymers optimized conditions CDSA length control fiber formation PDMS corona device applications solution self-assembly seeded-growth method Uniform Nanofibers PS nanofiber length control Analogous studies