Journal article
Layer with reduced viscosity at water-oil interfaces probed by fluorescence correlation spectroscopy
D Wang, L Pevzner, C Li, K Peneva, CY Li, DYC Chan, K Müllen, M Mezger, K Koynov, HJ Butt
Physical Review E Statistical Nonlinear and Soft Matter Physics | AMER PHYSICAL SOC | Published : 2013
Abstract
The two-dimensional diffusion of isolated molecular tracers at the water-n-alkane interface was studied with fluorescence correlation spectroscopy. The interfacial diffusion coefficients of larger tracers with a hydrodynamic radius of 4.0 nm agreed well with the values calculated from the macroscopic viscosities of the two bulk phases. However, for small molecule tracers with hydrodynamic radii of only 1.0 and 0.6 nm, notable deviations were observed, indicating the existence of an interfacial region with reduced effective viscosity and increased mobility. © 2013 American Physical Society.
Grants
Awarded by DFG
Funding Acknowledgements
The authors acknowledge financial support from DFG (Grant No. SPP1259 KO3747/3-1). C.Y.L. is grateful to the support of the Alexander von Humboldt Foundation.