Design and Morphological Investigation of High‑χ Catechol-Containing Styrenic Block Copolymers

We report the synthesis of multifunctional block copolymers (BCPs) showing a high Flory–Huggins interaction parameter (χ), which enable sub-10 nm line-space structures for a low degree of polymerization (<i>N</i>). The high χ BCPs are based on a poly­(3,4-dihydroxystyrene)–<i>block</i>-poly­(4-trimethylsilylstyrene) (PDHS-<i>b</i>-PTMSS) architecture. The controlled synthesis of the PDHS-<i>b</i>-PTMSS precursors was performed using user-friendly sequential nitroxide mediated polymerization (NMP) of poly­(3,4-diacetoxystyrene) and <i>block</i>-poly­(4-trimethylsilylstyrene) (PDAS-<i>b</i>-PTMSS). Thereafter, acid-catalyzed deprotection of the acetoxy moieties produced a library of PDHS-<i>b</i>-PTMSS BCPs with molecular weights ranging from 2.1 to 44.5 kg/mol. Bulk lamellar and cylindrical structures with periodicities as small as 8 nm were revealed by small-angle X-ray scattering. Moreover, PDHS-<i>b</i>-PTMSS thin films were assembled using solvent vapor annealing to define 10 nm line-space patterns in favorable conditions, i.e., at 20 °C for 20 min. In summary, our work brings further knowledge to the BCP toolbox for next-generation nanomanufacturing needs.