Two-Particle Microrheology of Quasi-2D Viscous Systems (original) (raw)

NASA/ADS

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Abstract

We study the spatially correlated motions of colloidal particles in a quasi-2D system (human serum albumin protein molecules at an air-water interface) for different surface viscosities ηs. We observe a transition in the behavior of the correlated motion, from 2D interface dominated at high ηs to bulk fluid dependent at low ηs. The correlated motions can be scaled onto a master curve which captures the features of this transition. This master curve also characterizes the spatial dependence of the flow field of a viscous interface in response to a force. The scale factors used for the master curve allow for the calculation of the surface viscosity ηs that can be compared to one-particle measurements.

Publication:

Physical Review Letters

Pub Date:

October 2006

DOI:

10.1103/PhysRevLett.97.176001

arXiv:

arXiv:cond-mat/0604262

Bibcode:

2006PhRvL..97q6001P

Keywords:

E-Print:

4 pages, 4 figures, submitted to PRL