Well-defined double-brush copolymers with each graft site carrying a polystyrene (PSt) graft and a polylactide (PLA) graft were synthesized by simultaneous reversible addition fragmentation chain transfer (RAFT) and ring-opening polymerization (ROP) processes, followed by ring-opening metathesis polymerization (ROMP) "grafting through" of the resulting diblock macromonomer (MM). Their Janus-type 1 morphologies were detected by transmission electron microscopy (TEM) imaging after thermal annealing to facilitate the intramolecular self-assembly of PSt and PLA grafts. This finding provides critical evidence to verify double-brush copolymers as Janus nanomaterials.
Li, Y., Themistou, E., Zou, J., Das, B. P., Tsianou, M., & Chong, C. (2012). Facile Synthesis and Visualization of Janus Double-Brush Copolymers. ACS Macro Letters, 1(1), 52-56. https://doi.org/10.1021/mz200013e