Fig. 5: Dodecane in water emulsions stabilized by ultra-low crosslinked (ULC) PNIPAM microgels.
From: Interactions between interfaces dictate stimuli-responsive emulsion behaviour
a–c Representative cryo-SEM images of ULC microgel at the emulsion interface in top view revealing the pronounced spreading of ULC microgels at the liquid interface. Compared to regular microgels (Fig. 3f–j), no ordered lattice is visible for ULC microgels and the area they occupy at the interface is ill-defined in size and shape (b, c). The top-view morphology of individual microgels is highlighted with green overlays (c). d–e Microgel morphology in cross-section accompanied by a schematic illustration (f). g, h Monomer-resolved Brownian dynamics simulations: Osmotic pressure Π exerted by either one (filled, representing flocculated emulsions) or two (hollow, representing dispersed emulsions) ULC microgels onto the liquid interface as a function of distance d in the swollen (g) and in the collapsed (h) state. A positive Π corresponds to a repulsive force of the microgels onto the two liquid interfaces. (i-iv) Representative snapshots of two ULC microgels at different compression states in the swollen (i-ii) and collapsed (iii-iv) states.
