Derry, Matthew J., Mykhaylyk, Oleksandr O., Ryan, Anthony J. and Armes, Steven P. (2018). Thermoreversible crystallization-driven aggregation of diblock copolymer nanoparticles in mineral oil. Chemical Science, 9 (17), pp. 4071-4082.
Abstract
A poly(behenyl methacrylate)37 (PBeMA37) macromolecular chain transfer agent is utilized for the reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate (BzMA) directly in mineral oil at 90 °C. Polymerization-induced self-assembly (PISA) occurs under these conditions, yielding a series of sterically-stabilized PBeMA37–PBzMAx diblock copolymer spheres of tunable diameter as confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM) studies. Rheological studies indicate that a relatively transparent, free-flowing, concentrated dispersion of non-interacting 32 nm PBeMA37–PBzMA100 spheres at 50 °C forms a turbid, paste-like dispersion on cooling to 20 °C. Turbidimetry and differential scanning calorimetry (DSC) studies conducted on solutions of PBeMA37 homopolymer in mineral oil suggest that this switchable colloidal stability is linked to crystallization-induced phase separation exhibited by this stabilizer block. Indeed, variable-temperature small-angle X-ray scattering (SAXS) indicates that a loose mass fractal network of strongly interacting spheres is formed on cooling to 20 °C, which accounts for this thermoreversible sol–gel transition. Moreover, SAXS, DSC and wide-angle X-ray scattering (WAXS) analyses indicate that the behenyl (C22H45) side-chains first form crystalline domains comprising adjacent stabilizer chains within individual spherical nanoparticles, with subsequent crystallization between neighboring nanoparticles leading to the formation of the mass fractal aggregates.
Publication DOI: | https://doi.org/10.1039/c8sc00762d |
---|---|
Divisions: | College of Engineering & Physical Sciences College of Engineering & Physical Sciences > School of Infrastructure and Sustainable Engineering > Chemical Engineering & Applied Chemistry College of Engineering & Physical Sciences > Aston Polymer Research Group |
Additional Information: | This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. |
Publication ISSN: | 2041-6539 |
Last Modified: | 07 Oct 2024 07:29 |
Date Deposited: | 07 Jan 2020 14:41 |
Full Text Link: |
http://www.scop ... tnerID=MN8TOARS |
Related URLs: |
https://pubs.rs ... 2D#!divAbstract
(Publisher URL) |
PURE Output Type: | Article |
Published Date: | 2018-04-02 |
Accepted Date: | 2018-04-01 |
Authors: |
Derry, Matthew J.
(
0000-0001-5010-6725)
Mykhaylyk, Oleksandr O. Ryan, Anthony J. Armes, Steven P. |