Polymers, Colloids & Interfaces, Contributed Talk (15min)

Self-Assembly of Polymeric Nanocapsules towards Multi-Functional Supracapsules

M. Hu1, N. Reichholf1, L. A. Frances1, S. N. Ramakrishna1, Y. Xia2,3, X. Cao2, S. Ma3, A. J. deMello2, L. Isa1*
1Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland, 2Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland, 3Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen, Fujian, China

The assembly of nanomaterials offers the possibility of fabricating functional materials for various applications. Compared with a single nanomaterial exhibiting a single function, the co-assembly of different nanomaterials allows performing multiple tasks simultaneously or in sequence.1-3 Usually, nanoparticles are the most commonly used building blocks in nanomaterials assembly. However, nanocapsules possess more functionality and versatility.4,5 Herein, we use evaporation-guided assembly to produce controlled assemblies of polymeric nanocapsules, called supracapsules. We first synthesize dextran-based nanocapsules with fluorescent dyes and superparamagnetic nanoparticles, by interfacial polyaddition in a water-in-oil miniemulsion. Subsequently, we confine the synthesized nanocapsules within monodisperse oil droplets in an oil-in-water emulsion obtained by microfluidics. After evaporating the oil, the nanocapsules spontaneously assemble into a spherical cluster, which we term supracapsule. By controlling the size of the droplets and the concentration of nanocapsules, the size of supracapsules can be finely tuned. After assembly, the resulting supracapsules preserve the functions presented in the nanocapsules. In the case of the incorporation of magnetic nanocapsules, the magnetic properties of supracapsules are enhanced compared with single nanocapsules, resulting in an easily controllable motion. Interestingly, the supracapsules have unique release kinetics compared with single nanocapsules. The release profile of encapsulated cargos in supracapsules can be further programmed. We envision that this new generation of assembled materials could promote the development of supraparticle-based materials for a wide range of applications.

[1] Zhihong Nie, Alla Petukhova, Eugenia Kumacheva, Nature Nanotechnology, 2010, 5, 15-25.

[2] Susanne Wintzheimer, Tim Granath, Maximilian Oppmann, Thomas Kister, Thibaut Thai, Tobias Kraus, Nicolas Vogel, Karl Mandel, ACS Nano, 2018, 6, 5093-5120.

[3] Songbo Ni, Jessica Leemann, Ivo Buttinoni, Lucio Isa, Heiko Wolf, Science Advances, 2016, 4, e1501779.

[4] Banu Iyisan, Katharina Landfester, Macromolecular Rapid Communications, 2018, 40, 1800577.

[5] Minghan Hu, Stefan Peil, Yaowen Xing, Diana Döhler, Lucas Caire da Silva, Wolfgang H. Binder, Michael Kappl, Markus B. Bannwarth, Materials Horizons, 2018, 1, 51-58.