Clean Block Copolymer Microparticles from Supercritical CO 2 : Universal Templates for the Facile and Scalable Fabrication of Hierarchical Mesostructured Metal Oxides

Bennett, Thomas M.; He, Guping; Larder, Ryan R.; Fischer, Michael G.; Rance, Graham A.; Fay, Michael W.; Pearce, Amanda K.; Parmenter, Christopher D. J.; Steiner, Ullrich; Howdle, Steven M.

Abstract

© 2018 American Chemical Society. Metal oxide microparticles with well-defined internal mesostructures are promising materials for a variety of different applications, but practical routes to such materials that allow the constituent structural length scales to be precisely tuned have thus far been difficult to realize. Herein, we describe a novel platform methodology that utilizes self-assembled block copolymer (BCP) microparticles synthesized by dispersion polymerization in supercritical CO 2 (scCO 2 ) as universal structure directing agents for both hydrolytic and nonhydrolytic sol-gel routes to metal oxides. Spherically structured poly(methyl methacrylate-block-4-vinylpyridine) (PMMA-b-P4VP) BCP microparticles are translated into a series of the corresponding organic/inorganic composites and pure inorganic derivatives with a high degree of fidelity for the metal oxides TiO 2 and LiFePO 4 . The final products are comprised of particles close to 1 μm in size with a highly ordered internal morphology of interconnected spheres between 20-40 nm in size. Furthermore, our approach is readily scalable, enabling grams of pure or carbon-coated TiO 2 and LiFePO 4 , respectively, to be fabricated in a facile two step route involving ambient temperature mixing and drying stages. Given that both length scales within these BCP microparticles can be controlled independently by minor variations in the reagent quantities used, the present general strategy could represent a milestone in the design and synthesis of hierarchical metal oxides with completely tunable dimensions.

Citation

Bennett, T. M., He, G., Larder, R. R., Fischer, M. G., Rance, G. A., Fay, M. W., Pearce, A. K., Parmenter, C. D. J., Steiner, U., & Howdle, S. M. (2018). Clean Block Copolymer Microparticles from Supercritical CO 2 : Universal Templates for the Facile and Scalable Fabrication of Hierarchical Mesostructured Metal Oxides. Nano Letters, 18(12), 7560-7569. https://doi.org/10.1021/acs.nanolett.8b03044

• Journal Article Type: Article
• Acceptance Date: Nov 8, 2018
• Online Publication Date: Nov 8, 2018
• Publication Date: Dec 12, 2018
• Deposit Date: Nov 22, 2018
• Publicly Available Date: Nov 9, 2019
• Journal: Nano Letters
• Print ISSN: 1530-6984
• Electronic ISSN: 1530-6992
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 18
• Issue: 12
• Pages: 7560-7569
• DOI: https://doi.org/10.1021/acs.nanolett.8b03044
• Keywords: Block copolymer; hierarchical; mesostructures; metal oxide; microparticle; sol-gel
• Public URL: https://nottingham-repository.worktribe.com/output/1299510
• Publisher URL: https://pubs.acs.org/doi/10.1021/acs.nanolett.8b03044
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [insert ACS Articles on Request author-directed link to Published Work, see https://pubs.acs.org/doi/10.1021/acs.nanolett.8b03044
• Contract Date: Nov 22, 2018