ABC triblock copolymer worms : synthesis, characterization and evaluation as Pickering emulsifiers for millimeter-sized droplets

Mable, C. J.; Thompson, K. L.; Derry, M. J.; Mykhaylyk, O. O.; Binks, B. P.; Armes, S. P.

Abstract

Polymerization-induced self-assembly (PISA) is used to prepare linear poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate)-poly(benzyl methacrylate) [PGMA-PHPMA-PBzMA] triblock copolymer worms or spheres in the form of a concentrated aqueous dispersion via a three-step synthesis based on reversible addition-fragmentation chain transfer (RAFT) polymerization. First, GMA is polymerized via RAFT solution polymerization in ethanol, then HPMA is polymerized via RAFT aqueous solution polymerization and finally BzMA is polymerized via ‘seeded’ RAFT aqueous emulsion polymerization. For certain block compositions, highly anisotropic worm-like particles are obtained, which are characterized by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The design rules for accessing higher order morphologies (i.e. worms or vesicles) are briefly explored. Surprisingly, vesicular morphologies cannot be accessed by targeting longer PBzMA blocks – instead only spherical nanoparticles are formed. SAXS is used to rationalize these counter-intuitive observations, which are best explained by considering subtle changes in the relative enthalpic incompatibilities between the three blocks during the growth of the PBzMA block. Finally, the PGMA-PHPMA-PBzMA worms are evaluated as Pickering emulsifiers for the stabilization of oil-in-water emulsions. Millimetre-sized oil droplets can be obtained using low-shear homogenization (hand-shaking) in the presence of 20 % vol. n-dodecane. In contrast, control experiments performed using PGMA-PHPMA diblock copolymer worms indicate that these more delicate nanostructures do not survive even these mild conditions.

Citation

Mable, C. J., Thompson, K. L., Derry, M. J., Mykhaylyk, O. O., Binks, B. P., & Armes, S. P. (2016). ABC triblock copolymer worms : synthesis, characterization and evaluation as Pickering emulsifiers for millimeter-sized droplets. Macromolecules, 49(20), 7897-7907. https://doi.org/10.1021/acs.macromol.6b01729

• Journal Article Type: Article
• Acceptance Date: Sep 21, 2016
• Online Publication Date: Oct 5, 2016
• Publication Date: Oct 25, 2016
• Deposit Date: Sep 26, 2016
• Publicly Available Date: Oct 5, 2016
• Journal: Macromolecules
• Print ISSN: 0024-9297
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 49
• Issue: 20
• Pages: 7897-7907
• DOI: https://doi.org/10.1021/acs.macromol.6b01729
• Keywords: Triblock copolymer worms
• Public URL: https://hull-repository.worktribe.com/output/443535
• Publisher URL: http://pubs.acs.org/doi/abs/10.1021/acs.macromol.6b01729
• Additional Information: Copy of article first published in: Macromolecules, 2016, v.49, issue 20
• Contract Date: Sep 26, 2016