Uniform shape monodisperse single chain nanocrystals by living aqueous catalytic polymerization.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31197178.
- Also identified by DOI 10.1038/s41467-019-10692-1 and PMC identifier 6565736.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The preparation of polymer nanoparticles with a uniform size and shape, beyond spheres, is an unresolved problem. Here we report a living aqueous catalytic polymerization, resulting in particles grown by a single active site and composed of a single ultra high molecular weight polyethylene (UHMWPE) chain. The control on a molecular level (M<sub>w</sub>/M<sub>n</sub> = 1.1-1.2) and at the same time on a particle level (PDI < 0.05) together with the immediate deposition of the growing chain on the growing nanocrystal results in a distinct evolution of the particle morphology over time. These uniform nanocrystals are obtained as concentrated aqueous dispersions of > 10 wt-% (N ≈ 10<sup>19</sup> particles L<sup>-1</sup>) polymer content. Key to this robust procedure to single chain nanoparticles are long-lived water-stable Ni(II) catalysts that do not undergo any chain transfer. These findings are a relevant step towards polymer materials based on nanoparticle assembly.