Clean block copolymer microparticles from supercritical CO2: universal templates for the facile and scalable fabrication of hierarchical mesostructured metal oxides

Research output: Contribution to journalLetterpeer-review

Authors

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

Colleges, School and Institutes

External organisations

  • University of Nottingham
  • Adolphe Merkle Institute

Abstract

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 CO2 (scCO2) 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 TiO2 and LiFePO4 . 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 TiO2 and LiFePO4 , 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.

Details

Original languageEnglish
Pages (from-to)7560-7569
Number of pages10
JournalNano Letters
Volume18
Issue number12
Publication statusPublished - 8 Nov 2018

Keywords

  • Block copolymer, hierarchical, mesostructured, metal oxide, microparticle, sol-gel