Temperature-Directed Formation of Anisotropic Kettlebell and Tadpole Nanostructures in the Absence of a Swelling-Induced Solvent

Sung-Po R Chen; Valentin A Bobrin; Zhongfan Jia; Michael J Monteiro

doi:10.1002/anie.202113974

Temperature-Directed Formation of Anisotropic Kettlebell and Tadpole Nanostructures in the Absence of a Swelling-Induced Solvent

Angew Chem Int Ed Engl. 2022 Mar 7;61(11):e202113974. doi: 10.1002/anie.202113974. Epub 2022 Jan 31.

Authors

Sung-Po R Chen¹, Valentin A Bobrin¹, Zhongfan Jia¹, Michael J Monteiro¹

Affiliation

¹ Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.

PMID: 35043533
DOI: 10.1002/anie.202113974

Abstract

Anisotropic Janus ("snowman") nanoparticles with a single protrusion are currently made via the solvent swelling-induced method. Here, we demonstrate without the aid of toxic solvents a generally applicable method for the formation of anisotropic polymer nanoparticles directly in water by controlling polymer mobility through tuning its glass transition temperature (T_g ). Spherical structures, formed immediately after the emulsion polymerization, transformed into uniform tadpoles (with head diameter ≈60 nm and tail length ≈130 nm) through the protrusion of a single cylindrical tail when cooled to a temperature above the T_g of the polymer. Cooling the spheres to below the T_g produced kinetically trapped kettlebell structures that could be freeze-dried and rehydrated without any structural change. These unique kettlebells could transform into uniform tadpoles by heating above the T_g , representing a triggered and on-demand structural reorganization.

Keywords: Anisotropic Nanoparticles; Asymmetric Structures; Emulsion Polymerization; RAFT Polymerization; TDMT.

Publication types

Research Support, Non-U.S. Gov't