Unexpected stability of aqueous dispersions of raspberry-like colloids.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30190497.
- Also identified by DOI 10.1038/s41467-018-05560-3 and PMC identifier 6127241.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Aqueous colloidal suspensions, both man-made and natural, are part of our everyday life. The applicability of colloidal suspensions, however, is limited by the range of conditions over which they are stable. Here we report a novel type of highly monodisperse raspberry-like colloids, which are prepared in a single-step synthesis that relies on simultaneous dispersion and emulsion polymerisation. The resulting raspberry colloids behave almost like hard spheres. In aqueous solutions, such prepared raspberries show unexpected stability against aggregation over large variations of added salt concentrations without addition of stabilisers. We present simple Derjaguin-Landau-Verwey-Overbeek (DLVO) calculations performed on raspberry-like and smooth colloids showing that this stability results from our raspberries' unique morphology, which extends our understanding of colloidal stability against salting. Further, the raspberries' stability facilitates the formation of superspheres and thin films in which the raspberry colloids self-assemble into hexagonally close-packed photonic crystals with exquisite reproducibility.