A microgel-Pickering emulsion route to colloidal molecules with temperature-tunable interaction sites

Soft Matter, vol. 16, pp. 1908–1921

Abstract

A simple Pickering emulsion route has been developed for the assembly of temperature-responsive poly(N-isopropylacrylamide) (PNIPAM) microgel particles into colloidal molecules comprising a small number of discrete microgel interaction sites on a central oil emulsion droplet. Here, the surface activity of the microgels serves to drive their assembly through adsorption to growing polydimethylsiloxane (PDMS) emulsion oil droplets of high monodispersity, prepared in situ via ammonia-catalysed hydrolysis and condensation of dimethyldiethoxysilane (DMDES). A dialysis step is employed in order to limit further growth once the target assembly size has been reached, thus yielding narrowly size-distributed, colloidal molecule-like microgel-Pickering emulsion oil droplets with well-defined microgel interaction sites. The temperature-responsiveness of the PNIPAM interaction sites will allow for the directional interactions to be tuned in a facile manner with temperature, all the way from soft repulsive to short-range attractive as the their volume phase transition temperature (VPTT) is crossed. Finally, the microgel-Pickering emulsion approach is extended to a mixture of PNIPAM and poly(N-isopropylmethacrylamide) (PNIPMAM) microgels that differ with respect to their VPTT, this in order to prepare patchy colloidal molecules where the directional interactions will be more readily resolved.

Authors 4

1. Linda K. Månsson

   Lund University · NanoLund

   Affiliation as printed

   Division of Physical Chemistry

   Lund University

   NanoLund

   SE-22100 Lund

   Sweden

   Division of Physical Chemistry, Lund University, POB 124, SE-22100 Lund, Sweden

   NanoLund, POB 118, SE-22100 Lund, Sweden

2. Feifei Peng

   Lund University · NanoLund

   Affiliation as printed

   Division of Physical Chemistry

   Lund University

   NanoLund

   SE-22100 Lund

   Sweden

   Division of Physical Chemistry, Lund University, POB 124, SE-22100 Lund, Sweden

   NanoLund, POB 118, SE-22100 Lund, Sweden

3. Jérôme J. Crassous Aachen Institute of Physical Chemistry

   RWTH Aachen University

   Affiliation as printed

   52074 AAchen

   Germany

   Institute of Physical Chemistry

   RWTH Aachen University

   Institute of Physical Chemistry, RWTH Aachen University, 52074 AAchen, Germany

4. Peter Schurtenberger corresponding

   Lund University · NanoLund

   Affiliation as printed

   Division of Physical Chemistry

   Lund University

   NanoLund

   SE-22100 Lund

   Sweden

   Division of Physical Chemistry, Lund University, POB 124, SE-22100 Lund, Sweden

   NanoLund, POB 118, SE-22100 Lund, Sweden