Unexpected stability of aqueous dispersions of raspberry-like colloids

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.

Polymeric raspberry-like particles via template-assisted polymerisation

“…Recently, we have shown that raspberry-like particles exhibit unprecedented stability against salt-induced aggregation over large variations of salt concentrations on account of their unique morphology. 34 In this study, we also find that the PMMA raspberry-like particles show incredibly high resistance to salt-induced aggregation (Fig. 4c).…”

Full-Spectrum High-Resolution Modeling of the Dielectric Function of Water

“…The huge amount of water at the earth's surface supports a multitude of dissolved gases and nano-particles that are significant in climate change; cf., for instance, black carbon [2]. Further issues related to water are the behaviour of oil films [3], the synthesis of nano-materials for medical applications [4,5], the behaviour of two-dimensional materials [6], and the behaviour of colloidal suspensions [7,8]. The functional mechanism of membranes [9,10] is also a relevant class.…”

Microfluidics‐Assisted Assembly of Injectable Photonic Hydrogels toward Reflective Cooling

“…It is clear that the hard PS@poly(HPA‐ co ‐VI) microspheres mostly crystallized into a hexagonal closely packed symmetric structure at the surface of the supraball. Such highly ordered surface is sufficient to promote the Bragg diffraction as evidenced by the reflection spectra (Figure e) . Additionally, the as‐prepared photonic supraballs exhibit excellent water stability and no obvious structural changes was detected after stored in water for up to 12 h (Figure S4, Supporting Information).…”