Figure 1

Chemical structures of the used tracers: (a) rhodamine, (b) PDI1, and (c) dendrimer.Reuse & Permissions

Figure 2

(a) Schematic of the FCS setup. (b) A fluorescence intensity scan through a water–$n$-decane interface on which rhodamine is adsorbed. Scanning was carried out by moving the focus from water into the $n$-alkane phase in steps of 200 nm. (c) Typical autocorrelation curves and their representation with Eq. (1) (solid lines) for rhodamine diffusing at water-decane (black squares) and water-dodecane (blue triangles) interfaces. The autocorrelation curve for rhodamine diffusing in bulk water (magenta circles) is shown for comparison.Reuse & Permissions

Figure 3

Normalized autocorrelation curves of (a) dendrimer and (b) PDI1 diffusing at various water-alkane interfaces and the corresponding fits with Eq. (1) in the main text (solid lines).Reuse & Permissions

Figure 4

(a) Interfacial diffusion coefficient $D_{\parallel }$ versus viscosity of the alkane phase measured for the dendrimer (solid circles), PDI1 (triangles) and rhodamine (squares) molecules at various water-alkane interfaces. The dashed line is a guide to the eye for rhodamine. The continuous line represents the values obtained with Eq. (2) for the dendrimer using $R=4.0$ nm and $\Theta ={90}^{\circ }$. The dotted line represents Eq. (2) with $R=1.0$ nm and $\Theta ={90}^{\circ }$ for the PDI1. The C$j$ on the top of the figure indicates the carbon number of the alkane used. The error bars evaluated from the statistical deviations of the measurements are smaller than the symbol size. (b) Schematic of a spherical particle at a water-alkane interface.Reuse & Permissions

Figure 5

Interfacial diffusion coefficient versus viscosity of the aqueous phase for rhodamine tracers at aqueous-hexane (open squares), aqueous-decane (open diamonds), and aqueous-dodecane (open triangles) interfaces. The solid circles represent the dendrimer tracers diffusing at aqueous-dodecane interfaces. The viscosity of the aqueous phase was adjusted by mixing water with glycerol.Reuse & Permissions

Figure 6

Diffusion time of quantum dots in bulk alkanes as a function of viscosity of alkanes; the red, dotted line represents the prediction of the Stokes-Einstein equation.Reuse & Permissions

Figure 7

Schematic illustrating the positions of the studied tracers at the water-alkane interfaces. The white region represents the reduced viscosity layer.Reuse & Permissions