In-situ investigation of self-assembled block copolymer nanostructural evolution during sulfonation-based crosslinking

Block copolymer (BCP) self-assembly provides a facile, low-cost method for developing intricate, well-ordered nanostructures with several applications, such as the synthesis of ordered mesoporous carbon (OMC). We have demonstrated the heterogeneous, sulfonation-based crosslinking of a triblock copolymer, polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene, for OMC synthesis, where crosslinking and nanostructural rearrangement occur simultaneously. This talk will present a systematic, in-situ study to develop fundamental understanding on the nanostructure evolvement during crosslinking, where a rich interplay between domain rearrangement and kinetic morphology trapping determines the final self-assembled nanostructure. Specifically, in-situ small-angle x-ray scattering (SAXS) will be employed to probe how sulfonation temperature and time affect domain spacing and degree of ordering. The morphological development of SEBS during crosslinking will be corresponded with their chemical transformation kinetics throughout the reaction. A relationship between sulfonation conditions and BCP self-assembly was established, providing opportunities for developing a process-tunable platform for intricate nanostructure control in ordered porous materials.