Polysulfobetaine-based diblock copolymer nano-objects via polymerization-induced self-assembly

Abstract

A zwitterionic polysulfobetaine-based macro-CTA is used for the synthesis of spheres, worms or vesicles via aqueous RAFT dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). These new diblock copolymer nano-objects exhibit high tolerance of added salt.

A Critical Appraisal of RAFT-Mediated Polymerization-Induced Self-Assembly

“…However, this has only been achieved for a small minority of PISA syntheses, 55,79,80,101 whereas many RAFT aqueous dispersion polymerization formulations enable access to such “higher order” morphologies. 34,46,54,70,71,89,102,103 Most literature examples of RAFT aqueous emulsion polymerization syntheses only result in the formation of kinetically-trapped spheres, even when targeting highly asymmetric diblock compositions. 35,95,96,104,105 These observations are currently not properly understood and surely warrant further work.…”

“…Generally speaking, it is good practice to examine a partially constructed phase diagram in order to inform further PISA syntheses, with the aim being to minimize uncertainty in the positions of the various phase boundaries. 103 …”

Incorporating Diblock Copolymer Nanoparticles into Calcite Crystals: Do Anionic Carboxylate Groups Alone Ensure Efficient Occlusion?

“…21−25 In particular, PISA syntheses can be conducted in concentrated aqueous solution, 26−40 and the size and morphology of the resulting diblock copolymer nano-objects can be readily adjusted by systematically varying the DP of the core-forming hydrophobic block. 26,41 Moreover, the surface chemistry of such nano-objects can be readily controlled by using nonionic, 26,42−44 anionic, 45,46 cationic, 47,48 or zwitterionic 49−51 blocks as the steric stabilizer for the PISA formulation.…”

One-pot synthesis of micron-sized polybetaine particles; innovative use of supercritical carbon dioxide

“…14 However, they can also be swollen by organic solvents due to their hydrophobic backbone (see SI - Figure S2 top right). Whilst this complicated amphiphilic behaviour allows polybetaines to find use as stabilisers of polymer colloids 42 and nano-objects in polymerisation induced self-assembly (PISA), 43 it also means that they do not reside within a single phase of the inverse emulsion systems, causes extensive aggregation occurring during the attempted dispersion polymerisation, and therefore illdefined particles (see SI - Figure S2 bottom). Because the standard synthesis attempts were unsuccessful, a new route was sought for the synthesis of PDMAPS particles.…”